Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers

Transcription

1 FANs 1162, 693 Issue Date 0401 APPLICATION NOTE Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers Variable Air Volume Modular Assembly (VMA) 1200 Series Controller Applications... *3 Introduction...*3 Key Concepts...*4 VMA1200 Series Controllers... *4 Variable Air Volume (VAV) System...5 VAV Terminal Box...6 VAV Box Fans...6 Control Loop... *8 Network Interface...13 VMA1200 Objects... *16 Application Description...*18 Q&A Path... *18 VMA Type... *20 Pressure Independent...20 Fan Control... *21 Space Temperature Input...23 Setpoint Calculation... *24 Occupancy Calculation... *33 Application (App) Mode Request Calculation... *36 Main Sequencer Control... *41 Cooling Loop... *44 Primary/Secondary Heating Loops... *47 * Indicates those sections where changes have occurred since the last printing Johnson Controls, Inc. Code. LIT

2 2 Room Sensors... *55 Sideloop Control...56 CO2 Control... *58 Diagnostics...60 Zone Bus Interface... *61 Network Variables...*62 Configuration Properties...*68 LONWORKS Technology...*78 * Indicates those sections where changes have occurred since the last printing.

3 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 3 Variable Air Volume Modular Assembly (VMA) 1200 Series Controller Applications Introduction The Variable Air Volume Modular Assembly (VMA) 1200 Series controller is an integrated module that includes the controller, actuator, and differential pressure sensor. VMA 1200 applications are developed to meet the LONMARK Space Comfort Control (SCC) profile using standard objects designed for the VMA. These applications are configured and downloaded to the VMA1200 using M-Pro software, available with M-Tool Release 2.0 or later. For more information about using M-Pro software, please refer to the M-Pro User s Guide (LIT ) in the M-Tool Manual (FAN 693). This document introduces the VMA1200 controller and provides procedures for the creation of single duct applications.

4 4 Key Concepts VMA1200 Series Controllers The VMA1200 is an integrated module that includes a VAV (Variable Air Volume) controller, actuator, and differential pressure sensor. VMA1200 applications can be used only with the VMA1200 controller; the VMA1200 applications cannot be downloaded to any other digital controllers, such as the Unitary (UNT) controller, the VMA1400 Series controller, or the VAV110. VMA1200 Series controllers support only single duct applications. vma1200 te: Figure 1: VMA1200 Controller Model The VMA1200 is available in two hardware models. The VMA1210 has no external Binary Outputs (BOs) or Analog Outputs (AOs) and is used in cooling only applications. The VMA1220 has five external BOs and one AO, which can be used for various single loop heating and sideloop control applications. The actuator on both models is controlled with internal outputs. For more information on the VMA1200 controller, refer to the documents listed in Table 1.

5 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 5 Table 1: Related Documentation For Information on This Topic Refer to: VMA1200 Product VMA1200 Installation VMA1200 Engineering VMA1200 Mounting and Wiring VMA1200 Downloading and Commissioning VMA1200 Troubleshooting Using the VMA Balancing Tool (VBT) Creating Applications and Editing Configuration Properties/Network Variables for the VMA1200 Mapping the VMA1200 VMA1200 Series Controller Product Bulletin (LIT ) VMA1200 Installation Sheet (Part ), packed with the product Variable Air Volume Modular Assembly (VMA)1200 Series Overview and Engineering Guidelines Technical Bulletin (LIT ) Mounting and Wiring VMA1200 Series Controllers Technical Bulletin (LIT ) Downloading and Commissioning VMA1200 Series Controllers Technical Bulletin (LIT ) Comm Pro User s Guide (LIT ) Troubleshooting VMA1200 Series Controllers Technical Bulletin (LIT ) Using the VMA1200 Balancing Tool (VBT) Software Technical Bulletin (LIT ) M-Pro User s Guide (LIT ) LONWORKS Compatible Devices Supported by NCM350 Technical Bulletin (LIT ) Variable Air Volume (VAV) System While generally maintaining constant supply air temperature, a VAV system adjusts the volume of air delivered to zones to maintain a desired zone temperature. The air flow rate required to maintain this desired zone temperature is determined by the size of the space, the internal heat generation, and external gains through the envelope. This is unlike the constant volume system that maintains a relatively constant airflow rate, but varies the temperature in response to changes in zone temperature. The supply air temperature and the static pressure of the air handling unit are controlled by the air handling unit controller, while each zone is controlled by a VAV controller. The air handler unit typically maintains a minimum of 0.5 to 1.5 in. W.C. (Water Column)/125 to 375 Pa static pressure in the supply duct. Most VAV applications are cooling only or cooling with reheat. In the cooling only situation, as the zone temperature increases, the VAV controller opens the box damper to allow more cool air to enter the space. For cooling with reheat applications, the controller enables heating control after the flow has been at minimum for a specified saturation time and the zone temperature falls below setpoint.

6 6 VAV Terminal Box While the heating control is active, the controller holds airflow constant at a specified heating flow (to allow for maximum heat transfer to occur and to minimize energy consumption while still providing acceptable ventilation) and modulates the heating device to satisfy setpoint. After the heating device has been at its minimum for a specified saturation time and the zone temperature rises above the cooling setpoint, the controller disables the heating control and enables the cooling control again. The VAV terminal box is a sheet metal box with a damper. The VAV controller positions the damper and actuator to act as a flow regulator varying the volume of air flow based on zone heating/cooling requirements. The basic parts of the VAV terminal unit are the VAV controller, actuator, flow rate sensor, chamber, zone temperature sensor, and damper. The size of the VAV terminal box, the static pressure at the box inlet, and the inlet air temperature determine its maximum cooling capacity. Therefore, the ability of the VAV terminal box to meet the zone temperature is dependent on the engineer s sizing practices. If the installed box is too small, the zone may overheat and audible noise may occur. If the installed unit is too large, there may be difficulty in controlling flow rate because a small change in damper position gives large changes in airflow. Boxes may be moderately oversized to allow for quiet operation or for reserve cooling capacity. VAV Box Fans Small fans are sometimes installed in VAV terminal boxes. These fans are installed either in series or parallel with the primary air damper. Both series and parallel fans can be implemented using the question and answer session in the M-Pro configuration tool. Series Fans Shown in Figure 2, the series fan is installed in series with the supply air stream. The conditioned air from the air handling unit is supplied into the fan chamber. Additional air is drawn from the ceiling plenum to maintain a relatively constant airflow into the zone. The constant speed fan discharges into the downstream supply air duct, which could contain a heating coil unit to warm the air before it is discharged to the zone. If cooling is not required, the primary air damper closes to its minimum flow rate settings and the air recirculates from the ceiling plenum. Series fans improve the comfort of occupants by maintaining a constant airflow through the diffuser, providing a better mix of air, regardless of the position of the air damper.

7 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 7 The series fan provides temperature based control. The series fan remains off during Shutdown and Calibration modes and runs continuously during Occupied and Standby modes. During Unoccupied mode, the fan cycles on and off if heating is required. Damper Actuator Primary (Duct) Air Fan Flow Adjust Airflow Pickup Secondary (Plenum) Air Optional Heating Cell series1 Figure 2: Single Duct VAV Box, Series Fan Parallel Fans Figure 3 shows the parallel fan arrangement in the single supply duct VAV box. When the box heating control is active, the parallel fan is started, which adds return air from the ceiling plenum to the discharge air. Damper Actuator Primary (Duct) Air Airflow Pickup Secondary (Plenum) Air Optional Heating Cell Fan Flow Adjust para1 Figure 3: Single Duct VAV Box, Parallel Fan

8 8 Control Loop Figure 4 shows a typical control loop with cooling and two sources of heat. Room Loop Temperature Sensor Cool Loop Flow Setpoint Cooling Working Setpoint PI with PRAC Flow Rate Span P-Adaptive Damper and Actuator Room Flow Calculation Flow Loop Pressure Sensor Heating Working Setpoint PI with PRAC Primary Heat Loop Actuator or Electric Heat PI with PRAC Secondary Heat Loop Actuator or Electric Heat PI Loops Coordinated Via Saturation Status (Heating/Cooling Sequencer) PI (Proportional + Integral Control) PRAC (Pattern Recognition Adaptive Control) P-Adaptive (Proportional-Adaptive Control) overview Figure 4: System Overview The difference between the cooling temperature setpoint and the zone temperature causes the cooling PI control loop to generate an output. This output is spanned between the minimum and maximum flow rate setpoints. The output of the flow span block is the flow setpoint for the flow loop. The difference between the flow setpoint and the box flow is used to position the damper. The flow loop uses P-Adaptive control, which provides fast response and minimum steady-state error. This cascaded control strategy is used because it has the ability to reject supply duct pressure fluctuations at the VAV box before they adversely influence the temperature in the zone.

9 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 9 When cooling is required, the VMA positions the damper as required to regulate the supply air at the quantities needed to maintain the zone temperature near setpoint. Refer to the Cool Loop and Flow Loop in Figure 4. Because the supply air is cool, the zone airflow increases when the zone temperature is above setpoint, and decreases when the zone temperature is below setpoint. To satisfy ventilation requirements, there is usually a minimum supply airflow. This is accomplished by setting the low limit of the flow rate span block shown in Figure 4. For exterior zones, reheat coils are commonly installed at the VAV box. If the VAV box is at its minimum flow and additional heat is required to maintain the zone setpoint, the reheat coil capacity is increased. This is accomplished via the actuator or electric heat control logic shown in Figure 4. Additional secondary heat (baseboard radiation) may also be sequenced. The VMA s velocity forms PI control loops that use the PRAC algorithm to automatically tune the control loop. This saves commissioning time and ensures stable control under all load conditions. te: PRAC (Pattern Recognition Adaptive Control) is not used with staged outputs such as electric heat coils. Proportional-Integral-Derivative (PID) The Heating, Ventilating, and Air Conditioning (HVAC) industry uses PID feedback control algorithms. The derivative portion is not available in the VMA1200, typically because it amplifies airflow noise and leads to instability. PI control algorithms have two parameters that affect controller performance: proportional gain and integral time. The HVAC controls manufacturer typically uses default PI control parameters shipped with the controller. The default parameters may not be appropriate, and using them can lead to poor control and performance. Also, many control loops require frequent re-tuning because external conditions affecting the heating and cooling dynamics of a space vary over time.

10 10 Pattern Recognition Adaptive Control (PRAC) 1 The VMA utilizes a Johnson Controls patented Pattern Recognition Adaptive Control (PRAC) algorithm to tune its PI feedback loops. The PRAC algorithm automatically adjusts the proportional band and the integral time of a PI control loop based on patterns of the sensed values from the process variable, setpoint, and the output of a PI control loop. PRAC uses a measure of the system damping and response speed of the process output to characterize the closed loop response with respect to setpoint changes and load disturbances. This results in near-optimal closed loop control performance. PRAC automatically adjusts to different process noise levels and has minimal calculation and memory requirements. Using PRAC reduces commissioning time for new control systems, eliminates operator time for re-tuning control loops and increases actuator life, since motor runtime is reduced. PRAC is used to tune the zone temperature control loop in pressure independent applications. When two position valves or electric heat are selected, PRAC should not be enabled. PRAC is automatically disabled at saturation, upon an error, and during an override situation. P-Adaptive Control 2 The P-Adaptive flow control algorithm uses a patented fixed gain, proportional control loop with a self-adjusting deadband whose value is related to an estimate of the noise variance. The P-Adaptive control strategy is used in the secondary flow control loop for pressure independent applications. P-Adaptive control has the advantage of much tighter flow control without oscillation. This is because it dynamically adjusts the flow deadband, based on the turbulence (noise) measured on the pressure sensor. P-Adaptive does not require any tuning. 1 2 Seem, J. E., A New Pattern Recognition Adaptive Controller, 13th Triennial IFAC World Congress, The International Federation of Automatic Control, San Francisco, CA., Volume K on Adaptive Control, Session on Auto-tuning and Adaptation, Paper 3B-043, pp , Peragamon, Federspiel, c., Flow control with Electric Actuators. International Journal of Heating, Ventilating, Air Conditioning, and Refrigeration Research, Vol. 3, 3.

11 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 11 Modes of Operation Table 2 and Table 3 provide a condensed overview of the controller actions for the possible modes of operation and during flow override conditions. tes: For the shaded areas, refer to the Main Sequencer Control section of this document. When the Fan Unocc Dmp Ovrd attribute of the HtgClgSeq object is true, it commands the damper to close when unoccupied and configured with a series fan, or when in heating mode and configured with either a parallel or parallel flow fan. This option may be used to prevent the fan from spinning backward in the UnOcc mode if the damper is left open. The information in Table 2 for the occupied mode also applies to standby mode. The only difference between the occupied and standby modes in the action of the damper, heat, fan, etc., are the setpoints for cooling and heating. The temperature setpoints are the standby setpoint values, but the action of the controller is the same as the occupied mode control.

12 12 Table 2: Modes of Operation for the VMA1200 Series-rmal Operation Mode/ Occupancy Heat/Occ Cool/Occ Heat/Unocc Cool/UnOcc Warm-up/ UnOcc Warm-up/ Occ Cooling Only Series Fan Parallel Fan Cooling Only with Reheat Damper controls to Cooling Minimum Flow. Damper modulates from Cooling Minimum to Maximum Flow. Damper controls to Cooling Minimum Flow. Damper modulates from Cooling Minimum to Maximum Flow. Same as Occupied Mode except controls to the Unoccupied Heating Setpoint. Maximum Heating Flow until space temperature reaches Occupied Heating Setpoint. Then box closes to Off mode. Damper controls to Heating Minimum Flow. Heat On. Fan On. Damper modulates from Cooling Minimum to Maximum Flow. Heat Off. Fan On. (Fan Unocc Dmp Ovrd is True) Damper closed. Heat On. Fan On (Fan Unocc Dmp Ovrd is False) Damper Controls to Heating Minimum Flow, Heat On. Fan On. (Fan Unocc Dmp Ovrd is True) Damper closed. Heat Off. Fan Off (Fan Unocc Dmp Ovrd is False) Damper Modulates. Heat Off. Fan Off. Same as Occupied Mode except controls to the Unoccupied Heating Setpoint. Maximum Heating Flow, Fan On until space temperature reaches Occupied Heating Setpoint. At Occupied Heating Setpoint Damper closes and Fan On. Heat Off. (except low limit) Damper controls to Heating Minimum Flow. Heat On. Fan Off (unless below Pfan minimum flow or Pfan based on Temperature) then On Damper modulates from Cooling Minimum to Maximum Flow. Heat Off. Fan Off. (unless below Pfan minimum flow) (Fan Unocc Dmp Ovrd is True) Damper closed. Heat On. Fan On. (Temperature or Flow based) (Fan Unocc Dmp Ovrd is False) Damper controls to Heating Minimum Flow. Heat On. Fan On. Damper modulates from Cooling Minimum to Maximum Flow. Heat Off. Fan Off. Same as Occupied Mode except controls to the Unoccupied Heating Setpoint. Fan always Off. Maximum Heating Flow, Fan Off (unless below Pfan minimum flow) until space temperature reaches Occupied Heating Setpoint. At Occupied Heating Setpoint Damper closes Fan Off. Heat Off. (except low limit) Damper controls to Heating Minimum Flow. Heat On. Damper modulates from Cooling Minimum to Maximum Flow. Heat Off. Damper controls to Heating Minimum Flow. Heat On. Damper modulates from Cooling Minimum to Maximum Flow. Heat Off. Same as Occupied Mode except controls to the Unoccupied Heating Setpoint. Maximum Heating Flow until Occupied Heating Setpoint. Box closes. Heat always Off. (except low limit) te: For the shaded areas, refer to the Main Sequencer Control section of this document. When the Fan Unocc Dmp Ovrd attribute of the HtgClgSeq object is true, it commands the damper to close when unoccupied and configured with a series fan, or when in Heating mode and configured with either a parallel or parallel flow fan.

13 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 13 Table 3: Modes of Operation for the VMA1200 Series-Flow Override Mode/ Occupancy Override- Closed/Occ or UnOcc Override- Open/Occ or UnOcc Override_Min/ Occ Override_Min/ UnOcc Override_Max/ Occ Override_Max/ UnOcc Cooling Only Series Fan Parallel Fan Cooling Only with Reheat Box goes Unoccupied. Damper closes. Damper opens. Damper controls to Minimum Cooling Flow. (CO2 adjusts minimum for all box types) t a show stopper! Damper controls to Minimum Cooling Flow. (CO2 adjusts minimum for all box types) t a show stopper! Damper controls to Maximum Cooling Flow. Damper controls to Maximum Cooling Flow. Box goes Unoccupied. Damper closes. Heat always Off. Fan Off. Damper opens. Heat always Off. Fan On. Damper controls to Min Cooling Flow. Heat always Off. Fan On. Damper controls to Minimum Cooling Flow. Heat always Off. Fan On. Damper controls to Maximum Cooling Flow. Heat always Off. Fan On. Damper controls to Maximum Cooling Flow. Heat always Off. Fan On. Box goes Unoccupied. Damper closes. Heat always Off. Fan Off. Damper opens. Heat always Off. Fan always Off. Damper controls to Minimum Cooling Flow. Heat always Off. Fan Off (unless below Pfan minimum flow) Damper controls to Minimum Cooling Flow. Heat always Off. Fan always Off. Damper controls to Maximum Cooling Flow. Heat always Off. Fan Off. (unless below Pfan minimum flow) Damper controls to Maximum Cooling Flow. Heat always Off. Fan always Off. Box goes Unoccupied. Damper closes. Heat always Off. Damper opens. Heat always Off. Damper controls to Minimum Cooling Flow. Heat always Off. Damper controls to Minimum Cooling Flow. Heat always Off. Damper controls to Maximum Cooling Flow. Heat always Off. Damper controls to Maximum Cooling Flow. Heat always Off. Network Interface The VMA1200 has a fixed set of data that can be accessed from the network (using LONWORKS compatible third-party software such as LonMaker software). This data is in the form of Network Variable Inputs (NVIs), Network Variable Outputs (NVOs), Network Configuration Inputs (NCIs) and Configuration Properties (CPs). These values are commonly referred to as the Device Profile. When an application is built by M-Pro software, it creates an object type (VAV PROFILE) named TCV VAV App (Figure 5 and Figure 6). The input attribute data of this object has connections that ultimately send data to the NVOs of the profile. These connections are made automatically and cannot be changed by the user. However, this object also holds NCI/CP attribute data that may be changed before the application is downloaded to the controller.

14 14 te: t all NVOs are supported by every application. If there is no connection to a specific NVO, it remains at its default value. Likewise, not all NCIs/CPs are used by every application, in those cases the CP value is ignored. Figure 5: TCV VAV App, Part 1

15 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 15 Figure 6: TCV VAV App, Part 2 Refer to Appendix A: Example of Network Management Tool Using M-Pro as a Plug-In: Echelon LonMaker Software in the M-Pro User s Guide (LIT ) or LonMaker literature for information on viewing NVIs, NVOs, NCIs, and CPs. In this document, NVIs and NVOs are referenced by their name and Metasys hardware reference (in brackets). For example, nvospacetemp [01AI26].

16 16 VMA1200 Objects Applications for the VMA1200 Series controller are constructed using input, output, and control objects. Objects are configurable and reusable features of the VMA1200 that contain both data and a means to act on that data to achieve desired results. It reads data from its inputs, performs some preset calculation using this data along with setup (configuration) data, and creates output data that can be used by other objects and/or be read from the network. The following diagram illustrates a typical view of an object through M-Pro software. There are references to the TCU and TCV, upon which the VMA1200 is based. Figure 7: Attribute Group Screen The Attribute GROUP column is the ObjectName assigned to the object by M-Pro software. It is used by other objects to reference input connections. The Attribute NAME column lists a set of Input and Setup attributes of the object that can be initialized by M-Pro software when the object is created. Each Object type has its own unique set of attributes that can be viewed by M-Pro software.

17 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 17 Inputs to the VMA1200 objects are performed through references to outputs from other objects. These inputs are viewed in the Value column. te that not all inputs require connections. Unconnected input attributes are blank. M-Pro software creates all the required and optional connections (references) based on how the questions in the Q&A (Question and Answer) session are answered. The user cannot create or change these connections. They appear in the Value column as REF ObjectName.AttributeName where the Object Name refers to an object or Attribute Group within the application and the Attribute Name is a valid output from that object. Setup attributes are also viewed in the Value column. Setup values are used by the object to set limits and modes of operation, and other information used by the controller. Setup data is initialized with appropriate default values by M-Pro software and can be changed by the user to meet specific application requirements. Setup values have associated units that appear in the Units column. All LONWORKS controllers default to SI (International Standard) units. The user may view the data in IMP (Imperial or English) units by selecting Action/Display Units or pressing Ctrl + U in M-Pro software. te: Some rounding error appears as the displayed units are toggled back and forth. This error should be insignificant in the actual application. The Execution Offset attribute establishes the order of execution of the object. M-Pro software uses this number to sort the objects before they are downloaded to the controller. The controller executes the objects in the order that they are downloaded. Inputs have low numbers, control objects mid-range numbers, and outputs high numbers. M-Pro software initializes this number and the user should not typically change it. Refer to Figure 7 for an example screen showing these attribute objects. The remaining attributes are specific to each object. See the specific headings in the Application Description section for information on how each object is used in the application as it is created by M-Pro software.

18 18 Application Description Q&A Path M-Pro software is a tool that steps through a series of questions that are answered by the user to configure an application that gets downloaded to the controller. This process is commonly referred to as a Q&A session. With each question that is answered, M-Pro software inserts specific standard objects into the application, makes connections to other objects, and initializes Attribute Data of the objects. After the Q&A session is completed, the user may need to change some of the Attribute Data specific to the application. te: The user cannot add objects or connections; this can only be done automatically by M-Pro software. This results in a finite set of fixed applications that can be performed by the controller. The remaining sections of this document provide more detail on what is happening when specific questions are answered, the objects that are created, and attributes of interest that might be changed. See Figure 8 for a diagram of the questions in the Q&A path. Refer to the individual sections in the Application Description section of this document for more information on each question and the variables/properties assigned with each answer.

19 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers What hardware device is being configured? (1210/1220) a. VMA1210 b. VMA1220 Q1 a Q2 1. Application Selection a. VMA1210/1220 Single Duct 3. Select the single duct VAV box control strategy: a. Pressure Independent Q3 4. Fan Type and Output Type: a. Fan b. Series Fan-BO c. Parallel Fan-BO-Temperature Based d. Parallel Fan-BO-Flow Based 5. Heating Configuration: a. ne (Cooling only) b. Single Source (Primary) c. Dual Source (Primary and Secondary) Q4 Q5 b c Q5b/ c 1 Q5b/c 1. Primary Heating: a. Position Adjust Output (Incremental) b. Analog Output c. Binary Output (rmally Open Valve) d. Binary Output (rmally Closed Valve) e. Electric 1-stage f. Electric 2-stage g. Electric 3-stage 6. Thermostat Style/Product: a. TMZ b. Metastat 7. Thermostat Type: a. Remote Adjust b. Remote Setpoint 8. Binary Input for Low Limit (Energy Hold Off) mode? a. b. Q6 a Q7 Q8 b Q5c 2 Q6b Q5c 2. Secondary Heating: a. Position Adjust Output (Incremental) b. Analog Output c. Binary Output (rmally Open Valve) d. Binary Output (rmally Closed Valve) e. Electric 1-stage f. Electric 2-stage g. Electric 3-stage Q6b. Thermostat Type: a. Remote Setpoint b. Warmer/Cooler Adjust c. Remote Setpoint VMAflow 9. Summer/Winter compensation of zone setpoint based on outdoor air temp: a. ne b. Outdoor Air Temp via Network Variable Q9 10. Local Occupancy Sensor? a. b. Q CO2 ventilation control strategies? a. b. Q Define Sideloop type: a. Sideloop b. Humidity Control (Voltage Input) Q12 Figure 8: Question and Answer Session

20 20 VMA Type Pressure Independent Application and Hardware Selection (Questions 1-2) An attribute group called VMA appears in the Attribute Data tab, which has a read-only Object Type attribute value of either TCV1210 DVC or TCV1220 DVC. This attribute cannot be changed and does not get downloaded to the controller. It is only used by M-Pro software when it compiles the application to determine if the selected hardware model has the correct number and types of I/O to handle the application configuration. In pressure independent control schemes, two feedback control algorithms (Proportional-Integral [PI] and Proportional-Adaptive [P-Adaptive]) cascade together in the flow and temperature control loops. The primary loop controller uses the PI algorithm to generate an airflow setpoint for the secondary loop using the P-Adaptive algorithm. The PI algorithm is supplemented by the PRAC algorithm based on the zone temperature error. The secondary loop modulates the box damper as required to minimize the difference between airflow rate measured at the box inlet and the flow rate setpoint. This secondary loop rejects arbitrary supply duct static pressure disturbances before they adversely influence the zone temperature. VMA Control Strategy (Question 3) The VMA1200 uses a pressure independent application to control the VAV box supply flow, independent of the supply duct static pressure variations. The control strategy question only has one answer in the Q&A path at this time.

21 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 21 Fan Control Fan Type and Output Type Choose from the options in Table 4. Table 4: Fan Type and Output Type (Question 4) Option Description Fan Series Fan-BO Parallel Fan-BO- Temperature Based Parallel Fan-BO- Flow Based points, properties, or logic are assigned for this answer. The series fan remains off during Shutdown and Calibration modes and runs continuously during Occupied and Standby modes. During Unoccupied mode, the fan cycles on if heating is required. Prior to starting the fan, the damper is driven closed for the fan start delay time plus the damper stroke time to ensure that the fan is not rotating backwards. During warmup, the series fan cycles on if heating is required. A single BO is used. When this option is selected, the parallel fan remains off during Shutdown and Calibration modes and cycles on whenever the Heating modes are active, regardless of Occupancy mode. If box heating is not chosen for this box, the temperature based parallel fan is not turned on. A single BO is used. When this option is selected, the parallel fan remains off during Shutdown and Calibration modes and cycles on whenever the Heating modes are active during the Unoccupied mode. In addition, the parallel fan is cycled on during Standby and Occupied modes when the supply flow is less than the parallel fan minimum flow. A single BO is used. Depending on the answer to the fan question, M-Pro software adds the Fan Controller and BO Fan objects with default values. setup properties can be changed by the user. The Fan Controller object manages all the box fan types used by VMA1200 Series controllers. In parallel fan powered terminal boxes, the fan runs intermittently to produce a flow of plenum air through the box, whenever needed. This occurs even if the box damper is fully closed to the primary air source. When configured as Parallel Fan Based On Supply Flow, the fan remains off during Shutdown and Calibration modes and cycles during Standby and Occupied modes when the supply flow is greater than the value of the parallel fan minimum flow property. During Unoccupied mode, the fan is cycled when heating is required. When configured as Parallel Fan Based on Temperature, the fan remains off during Shutdown and Calibration modes and when the heating is active.

22 22 Table 5: Fan Control Attribute Groups Table 5 shows the attribute groups involved in fan control. Attribute Group Name Fan Controller BO Fan Function Controls the three fan types used with the VMA1200: no fan, parallel fan, or series fan. Takes commands from the output value of the Fan Controller and controls a physical binary output. Attribute Comments Fan state can be overridden from the network using nvifanspeedcmd [01MO10B] and the current state can be monitored on nvofanspeed [01BO276]. Slot: Defaults to BO1 with a rmal Polarity. Setup: Should remain as an On/Off Type. Figure 9 shows a screen showing fan control attributes. Figure 9: Fan Control Attribute Group Example Refer to Table 2 and Table 3 in this document for more information on how control over different fan types changes based on HeatCoolMode, Occupancy Mode, Air Flow, and flow sensor reliability.

23 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 23 Space Temperature Input M-Pro software adds two objects that measure and condition the space temperature (Table 6). Figure 10 shows a screen with space temperature attributes. Table 6: Space Temperature Input Attribute Groups Attribute Group Name Space Temp AI SW AI Filter Function Measures and conditions the space temperature by reading the physical analog input and calculates a temperature value. Conditions the space temperature by removing noise and calibrating the value from the Space Temp AI object. Attribute Comments Value of the temperature sensor can be overridden by writing a value to nvispacetemp. Output Range High, Output Range Low, and the Offset: Should not be changed. Input Offset: May be modified to account for an excessive amount of resistance in the wiring between the sensor and the controller. Filter Weight: Should remain at 0. Setup: Defaults at Nickel Linearization on Slot 1. Change these values if a sensor type other than TE-6x00 is used or if it is physically connected to some other analog input. Generally, leave these settings at default. The output from this object can be monitored from nvospacetemp [01AI26]. Offset: Read the Offset from the VAV profile cptempoffset. If necessary, change before the application is downloaded to the controller or during field commissioning by a network tool. Spike Window: Sets the maximum for the adaptive anti-spike window to detect invalid electrical signals in the sensor environment or an intermittent sensor fault. Filter Coeff: A second order low pass butterworth digital filter that removes noise above a cutoff frequency (0.024 Hz).

24 24 Figure 10: Space Temperature Input Attribute Group Example Setpoint Calculation Summer/Winter Compensation of Zone Setpoint Based on Outdoor Air Temperature Choose from the options in Table 7. Table 7: Summer/Winter Compensation of Zone Setpoint Based on Outdoor Air Temperature (Question 9) Option Description ne Outdoor Air Temp via Network Variable points, properties, or logic are assigned for this answer. Summer/winter compensation allows temperature setpoint reset based on outdoor air temperature. The Space Temperature Setpoint is determined based on a series of calculations based on the type of thermostat used and whether Summer/Winter compensation is used. See Table 8 for descriptions of the Setpoint Calculation attribute groups. Figure 11 shows a screen of setpoint calculation attributes.

25 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 25 Table 8: Setpoint Calculation Attribute Groups Attribute Group Name Space Setpoint AI Summer/Winter Setpoint Calc Function Reads an external setpoint potentiometer. An analog input used to obtain the space temperature setpoint. The AI can be either a Remote (absolute, for example ) type or a warmer/cooler [relative, for example, +/- 3 ] type. The warmer/cooler type is not available with a TMZ1600 sensor. Adds a bias to the space temperature setpoints based on outdoor air temperature and the Occupancy mode when Outdoor Air Temp via network variable is selected in the Q&A session. Makes the final calculation of the effective heating and cooling setpoints that are used by the heating and cooling PIs. Helps to determine the space temperature setpoint. This calculation uses the LONMARK Asymmetrical Setpoint Calculation method. Attribute Comments Some attributes may have to be changed if you use a thermostat that is not the thermostat (TE-6x00 or TMZ1600) style. Remote Setpoint Max/Min: Values can be adjusted through the profile object or with a network tool to change the range of the setpoint. Input Range High/Low: Change these values if other than a TE-6x00 sensor is used. nvioutdoortemp [01A019] should be bound in a networked system or commanded from a Metasys Network. setup properties can be changed by the user.

26 26 Figure 11: Setpoint Calculation Attribute Groups Example Absolute Setpoint If Remote Setpoint is selected in the Q&A session and/or nvisetpoint [01AO02] is written to, then it overrides the SpaceSetpoint AI and its value is used as the Setpoint input to the SetpointCalc object. Warmer/Cooler Setpoint If Remote Setpoint is selected and/or nvisetptoffset is written to, then nvisetptoffset overrides the SpaceSetpoint AI and its value is used as the Setpoint Offset input to the SetpointCalc object. Setpoint (Offset) = Space Setpoint AI When not overridden, the Space Setpoint AI calculates the setpoint with the following equation: AI Value + InputRange (RemoteInput Max-RemoteInput Min) + RemoteInput Min (InputRange High-InputRange Low) * Low

27 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 27 Summer/Winter Compensation This attribute object alters the temperature setpoint when the outdoor air temperature exceeds specific limits. Figure 12 and the following equation illustrate how the setpoint shift is calculated based on the outdoor air temperature input and the six configuration properties. xxxshift = (OutdoorTemp xxxsetpoint) * xxxauthority if xxxshift > xxxlimit, then xxxshift = xxxlimit where: xxx = ncisummer or nciwinter Effective Setpoint Shift ( F) Summer 5 4 Compensation Limit (+5 F) Winter Authority (+0.1) Winter Authority -2 (-0.1) Winter Setpoint -3 Winter (60 F) -4 Compensation Summer Setpoint Limit (-3 F) -5 (76 F) Summer Authority (+0.2) Outdoor Air Temperature ( F) stptshift Figure 12: Summer/Winter Setpoint Shift When not overridden (using nvisetptshift), the calculation provides an equal shift for Occupied and Standby modes for heating (winter compensation) and cooling (summer compensation). The unoccupied shifts are always set at zero. Setpoint Calculator Calculates the effective heating and cooling setpoints based on the current occupancy mode. The calculation uses the LONMARK Asymmetrical Setpoint Calculation method. First, the absolute setpoint is calculated as the difference between the setpoint input and the mean of the occupied cooling and occupied heating setpoints. setup values can be edited by the user, but Table 9 shows the M-Pro makes based on the type of thermostat used. Table 9: Setpoint Connections Made by M-Pro Software TE-6x00 with Remote Setpoint or Remote Setpoint TE-6x00 with Warmer/Cooler Setpoint Setpoint Input Setpoint AI nvisetpoint [01AO02] Setpoint Shift (six values) nvisetptshift [01AO041 to 01AO046] or Summer/Winter Setpoint Offset nvisetptoffset [01AIO3] Setpoint AI nvisetptshift [01AO041 to 01AO046] or Summer/Winter

28 28 Table 10: Setpoint Calculations The absolute setpoint offset is calculated as follows: absspoffset = SetpointInput - [(ncisetpoint.occ_cool - ncisetpoints.occ_heat)/2] te: If SetpointInput is not valid, the absspoffset is set to 0. The effective heating and cooling setpoints are absolute values and are calculated as follows based on occupancy mode: Occupancy Mode Occupied and Bypass Standby Unoccupied Setpoint Calculations Cooling=nciSetpoints.occ_cool+absSpOffset+SetpointOffset+SetpointShift.occ_cool Heating=nciSetpoints.occ_heat+absSpOffset+SetpointOffset+SetpointShift.occ_heat Cooling=nciSetpoints.standby_cool+absSpOffset+nviSetptOffset+SetpointShift.standby_cool Heating=nciSetpoints.standby_heat+absSpOffset+nviSetptOffset+SetpointShift.standby_cool Cooling=nciSetpoints.unocc_cool+SetpointShift.unocc_cool Hetating=nciSetpoints.unocc_heat+SetpointShift.unocc_cool The heating and cooling setpoints are also clamped by the Maximum Heating Setpoint and the Minimum Cooling Setpoint respectively. For example, an application using the given properties TE-6x00 room sensor with an absolute setpoint set for 65 to 85 F (18.3 to 29.4 C). Set to 70 F (21.1 C). ncisetpoints.occ_cool = 74 F (23.3 C) ncisetpoints.occ_heat = 70 F (21.1 C) ncisummerauth = 0.1 F (0.1 C) ncisummersetpoint = 80 F (26.7 C) ncisummerlimit = 5 F (2.78 C) nvisetpoint = INVALID (t overriding the Setpoint AI) nvisetptoffset = INVALID (t controlled from network) nvisetptshift = INVALID (t overriding the Summer/Winter calculation) nvioutdoortemp = 85 F (29.4 C) (As written from Metasys system) Then using the above table and formula: SetpointInput = 70 F (21.1 C) (from Setpoint AI) SetpointShift = 0.5 F (.278 C) = (85-80) * 0.1 F or [( )*.056 C] (from Summer/Winter object) SetpointOffset = 0 (from nvisetptoffset) absspoffset = -2 F (-1.10 ) = 70 [(74+70)/2] F or 21.1 [( )/2] C

29 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 29 Then Occ CoolingSetpoint = 72.5 F (22.5 C) = 74 + (-2) F or ( C) Occ HeatingSetpoint = 68.5 F (20.3 C) = 70 + (-2) F or ( C) Setpoint Calculation Example There are six values in the ncisetpoints configuration property that establish three deadband zones for the controller: one for Occupied, one for Standby, and one for Unoccupied. If the actual room temperature is within an active deadband zone, then the controller is said to be satisfied. The diagram illustrates the three satisfied deadband regions. te: While the deadband regions are shown to be symmetrical, symmetry is not required. ncisetpoints Effective Setpoints unoccupied_cool standby_cool Cooling Region unoccupied_cool standby_cool occupied_cool occupied_cool Occupied Standby Unoccupied Satisfied Region occupied_heat standby_heat occupied_heat unoccupied_heat standby_heat unoccupied_heat Heating Region rmal Setpoint Active Setpoint Figure 13: Setpoints setpoints

30 30 The minal Setpoint is always equal to the average of the occupied_heat and occupied_cool values as set in the ncisetpoints configuration property. The Active Setpoint can come from several sources. If a warmer/cooler adjust stat is being used, the Active Setpoint is the sum of the nvisetpoint [01AI03], nvisetptoffset [01AI03], and the offset from the stat. If an absolute adjust stat is being used, then the Active Setpoint is the sum of the value from the stat (typically F) and the nvisetptoffset [01AI03]. If no stat is being used, then the Active Setpoint is the sum of nvisetpoint [01AI02] and nvisetptoffset [01AI03]. The Active Setpoint is used by the controller to shift the baseline values set in ncisetpoints and determine an effective setpoint. As the Active Setpoint is increased/decreased above/below the minal Setpoint, the six mode setpoints move proportionally. The controller chooses the appropriate setpoint based on the current heat/cool mode and occupancy state of the controller. This effective setpoint can be viewed by monitoring nvoeffectsetpt [01AI28]. te: The effective setpoint can be further adjusted by using Summer/Winter compensation or writing to the nvisetptshift [01AO41 to 01AO46] values. However, this is beyond the scope of this example. Using a vertical line along the Active Setpoint as a reference line, if the controller is in a cooling mode when the zone temperature falls into the active satisfied region, then it remains in the cooling mode and the flow is controlled to the minimum cooling setpoint (nciminflow). Likewise, if the controller is in a heating mode and the room temperature increases into the active satisfied region, the controller remains in the heating mode with the heating outputs off and the flow being controlled at the minimum heating flow setpoint (nciminflowheat). Depending on the heating load, the room temperature may rise or fall when the controller is operating in the satisfied region. The controller does not switch heat/cool modes until the room temperature enters the opposite Heating or Cooling Region and the appropriate saturation timer has expired.

31 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 31 For an example (see Figure 14), assume the controller is in an occupied state and cooling mode. The nvisetpoint is 72 F and the warmer/cooler stat is set to 3 F giving an Active Setpoint of 75 F, which means the effective setpoint is the occupied_cool setpoint of 77 F. The controller is maintaining the zone temperature and delivering 40% flow to the space. It s cold outside so the room temperature begins to fall. The room temperature enters the occupied Satisfied Region. The controller remains in the cooling mode and ramps down to the minimum cooling flow trying to heat the space. When the room temperature falls below the effective occupied_heat setpoint of 73 F the controller enters the heating mode, bringing up its heating outputs and changing the flow value to the minimum heating flow setpoint. w the controller heats to the effective occupied_heat setpoint. After a while, the heating output may reach 50% to maintain the room temperature at the 73 F setpoint. Then a command comes from the network to enter the unoccupied state. The controller sets the new effective setpoint to the unoccupied_heat setpoint of 69 F. The controller sees that it is in the unoccupied satisfied state, ramps the heating output down to 0 to cool the space, and maintains the airflow at the minimum heating flow setpoint. This allows the room temperature to fall further to the 69 F setpoint. The next day is Saturday so the space stays unoccupied. The room begins to heat up during the day. The controller remains in the heating mode, ramps down the heating output to 0, and waits until the room temperature exceeds the unoccupied_cool setpoint of 81 F. Then it enters the cooling state and regulates the flow to maintain 81 F.

32 32 NciSetpoints Effective Setpoints unoccupied_cool = 77 standby_cool = 75 Cooling Region 81 = unoccupied_cool 79 = standby_cool 77 = occupied_cool occupied_cool = Occupied Standby Unoccupied 71 Satisfied Region 73 = occupied_heat 71 = standby_heat occupied_heat = = unoccupied_heat standby_heat = 67 unoccupied_heat = 65 Heating Region rmal Setpoint = 71 Active Setpoint = 75 setptex Figure 14: Setpoint Example

33 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 33 Occupancy Calculation Local Occupancy Sensor Choose from the options in Table 11. Table 11: Local Occupancy Sensor (Question 10) Option Description Assigns points, properties, and logic for the local occupancy sensor attached to a Binary Input. points, properties, or logic are assigned for this answer. Figure 15 illustrates the five objects associated with the Occupancy Mode Control and the connections made between the objects. Table 12 describes the occupancy calculation attribute groups. OccupancyButton Binary Input BO6 LED Digital Output Occupancy Mode Calculation nvioccmancmd ncibypasstime nvioccschedule nvioccsensor OccSensor Binary Input TempOcc Effective OccManCmd OccSchedule RemoteValue OccSensor (opt.) OccupancyStatus OccRelate nvoeffectoccup Figure 15: Occupancy Calculation Relationship

34 34 Table 12: Occupancy Calculation Attribute Groups Attribute Group Name Occupancy Button Temp Occ BO6 LED Occupancy Sensor Occ Mode Function Monitors the state of the Temp Occ pushbutton on a room sensor or from a separate binary input. Controls the Temporary Occupancy (Bypass) timer. Starts a timer for the time in ncibypasstime when the OccupancyButton has been pressed. It outputs OC_BYPASS to the OccMode Object. Monitors the Temp Occ object. Used when a local occupancy sensor is attached to a binary input. Calculates the effective occupancy mode based on the data connected to its inputs. Attribute Comments Slot 1: Binary Input. If a TE-6700 room sensor is used, the Temporary Occupancy button shorts a separate binary output (BI-1). This is a hardware selection only. If a TMZ1600 is used, the TMZ overrides the BI-1 state for 5 seconds and then releases it. setup properties can be changed by the user. nvioccmancmd [01MS06 or 01MO06] overrides the Temporary Occupancy timer and any other value than OC_NUL passes directly to the OccMode object. OC_BYPASS is the LONWORKS equivalent for Temp Occ. Slot: 6 is an internal output that drives a LED (Light-Emitting Diode) on a TE-6700 room sensor. When the Temp Occ bypass timer is running, then the output is On. Slot: Defaults to a normally open dry contact binary input. Polarity: Set to Reverse if the sensor is a normally closed type. setup data can be adjusted by the user.

35 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 35 Figure 16 shows a screen with occupancy calculation attributes. Figure 16: Occupancy Calculation Attribute Group Example Occupancy Mode Calculation Table 13 shows how the Occupancy Mode object from the OccupancySensor calculates the Effective Occupancy Sensor (if used) and the nvioccsensor network input. Table 13: Effective Occupancy Sensor Calculation Occupancy Sensor (local sensor input) t Used (t Connected) Used (Connection Present) False Remote Input [nvioccsensor (01BI07)] OC_NULL OC_UNOCCUPIED OC_OCCUPIED OC_NULL OC_UNOCCUPIED Effective Occ Sensor (internal) OC_OCCUPIED OC_UNOCCUPIED OC_OCCUPIED OC_UNOCCUPIED OC_UNOCCUPIED OC_OCCUPIED OC_OCCUPIED True Don t care OC_OCCUPIED The Occupancy Mode object calculates the EffectiveOccupancy using Table 14. The value is used by many other objects in the application and can be monitored from nvoeffectoccup [01MI24].

36 36 Table 14: Effective Occupancy Calculation Effective OccSchedule (input) 2 Effective OccSensor EffectOccup OccManCmd (input) (Internal) 3 (output) OC_OCCUPIED Don t care Don t care OC_OCCUPIED OC_UNOCCUPIED Don t care Don t care OC_UNOCCUPIED OC_BYPASS 1 OC_OCCUPIED Don t care OC_OCCUPIED OC_UNOCCUPIED Don t care OC_BYPASS OC_STANDBY Don t care OC_BYPASS OC_NUL OC_OCCUPIED OC_OCCUPIED OC_UNOCCUPIED OC_BYPASS OC_STANDBY Don t care Don t care OC_STANDBY OC_NUL OC_OCCUPIED OC_OCCUPIED OC_OCCUPIED OC_UNOCCUPIED OC_STANDBY OC_UNOCCUPIED Don t care OC_UNOCCUPIED OC_STANDBY Don t care OC_STANDBY OC_NUL OC_OCCUPIED OC_OCCUPIED OC_UNOCCUPIED OC_UNOCCUPIED tes: 1. OC_BYPASS occurs when nvioccmancmd is OC_NUL and the TempOcc timer is running. 2. nvioccschedule [01MO051] references the current state field only. 3. The occupancy sensor can be either a local input (OccSensor) or a network input (Remote Input) or both. See Table 13 for how these inputs affect the Effective OccSensor. Application (App) Mode Request Calculation Binary Input for Low Limit (Energy Hold Off) Mode Choose from the options in Table 15. Table 15: Binary Input for Low Limit (Energy Hold Off) Mode (Question 8) Option Description This choice assigns points, properties, and logic to provide a low limit operation of supplemental heating. When a binary input such as a window contact or overhead door switch, indicates Low Limit mode, the VAV box damper closes, all fans (if present) and box heating (if present) turn off. If the zone temperature drops below the low limit setpoint, the supplemental heat (if present) operates to maintain the zone temperature. points, properties, or logic are assigned for this answer. The Low Limit mode for this application can only be activated by a user override of the VAV Box mode.

37 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 37 The Application Mode Calculation determines a requested mode of operation of the controller. rmally, the output from this is HVAC_AUTO which allows the Main Sequencer (Heating Cooling Sequencer [HtgClgSeq]) to determine the actual mode. This value can be affected by the LowLimit object, the BIWindowContact object and several NVs and NCs. Table 16 lists the attribute groups used in AppMode. Figure 17 shows a screen with AppMode attributes, Figure 18 displays the inputs and outputs for AppMode, and Figure 19 gives an overview of the AppMode connections made by M-Pro software. Table 16: Application Mode Attribute Groups Attribute Group Name Low Limit BI Window Contact App Mode Function Monitors the space temperature from the SW AI Filter object (see the Space Temperature Input section). Monitors BI 3 and Energy Hold Off. If either of these is true, a true is passed to the AppMode object. Prioritizes information from the Low Limit object, BI Window Contact object, and several NVs to determine mode of operation. Htg Clg Seq object makes the final mode of operation decision. Attribute Comments If the value of the low limit falls below the limit set in ncispacelowlimit, then this object is true. Once true, the output is true until the space temperature is greater than the ncispacelowlimit+ncispacelowdiff. Space Low Limit: 50 F default. Change this value via the TCV VAV App Profile object prior to download or using the network management tool during commissioning. Space Low Differential: 3.6 F default. Change this value via the TCV VAV App Profile object prior to download or using the network management tool during commissioning. Setup: Defaults to Input or NV. This value can be changed to Input and NV to logically AND the Binary Input state of the network variable or to "PV=NV" to ignore the Binary Input state. Slot: Defaults to 3, can be changed to 1 or 2 depending on where input is wired. Polarity: Defaults to rmal, but can be changed to Reverse if a normally closed window contact is used. setup properties can be changed by the user. Priorities for mode: Low Limit input > BI Window Contact input > nviapplicmode > nviheatcool (highest to lowest)

38 38 Figure 17: Application Mode Attribute Example From SpaceTemp AppMode ncispacelowdiff ncispacelowlimit LowLimit LowLimit nviheatcool Mode Request Output To Main Sequencer ncidefaulthvacmode Default HVAC Mode nvienergyholdoff BIWindowContact Binary Input EnergyHoldOff appmode Figure 18: Application Mode Inputs and Outputs

39 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 39 App Mode Object Starting at the bottom of Figure 19, the status from the LowLimit object has the highest priority. If TRUE (1), then the Mode Request is set to HVAC_EMERG_HEAT for emergency heat. Next in priority is the Energy Hold Off status from the BIWindowContact object or directly from nvienergyholdoff if no input is used. If this is indicating TRUE, then the requested status is forced to HVAC_OFF and the controller stops controlling both the Heating and Cooling outputs. te: This does not mean than the outputs drive to 0, they just stay where they are. The nviapplicmode [01MO08B or 01AO08] has the next higher priority. Its value passes to the output if it is anything other than HVAC_AUTO or HVAC_WARMUP. If its value is HVAC_AUTO, then the value determined from nviheatcool [01MO09A or 01AO09]. If its value is HVAC_WARMUP and nviheatcool is HVAC_EMERG_HEAT, then the requested mode sets to HVAC_EMERG_HEAT, else it sets to HVAC_WARMUP. The lowest priority override comes from nviheatcool. This value overrides the value set in ncidefaulthvacmode (default value of AUTO) whenever it is set to anything other than HVAC_AUTO.

40 40 Application Mode Object HVAC Mode Default HVAC Mode Heat (1) Warmup (2) Cool (3) Night Purge (4) Pre Cool (5) Off (6) Test (7) Emerg Heat (8) Fan Only (9) Max Heat (12) 1-9, HVAC Auto HVAC Heat HVAC Mrng Wrmup HVAC Cool HVAC Night Purge HVAC Pre Cool HVAC Off HVAC Test HVAC Emerg Heat HVAC Fan Only HVAC Max Heat HVAC annual (0xFF) (9) (9) nviheatcool (01MO09a) nviapplicmode (01MO08B) Emerg Heat (8) Warmup (2) 8 Heat (1) 8 Cool (3) Night Purge (4) Pre Cool (5) Off (6) Test (7) Emerg Heat (8) Fan Only (9) Max Heat (12) 1-9, Emerg Heat (8) Off (6) Heat Cool Request Energy Hold Off Low Temp Status appmodeflow Figure 19: Application Mode Connections

41 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 41 Main Sequencer Control The Main Sequencer controls the sequencing between cooling and heating modes with up to two heating sources. M-Pro software adds the correct objects depending on the answer given to the Heating Configuration question. Table 17 describes the Heating/Cooling Sequencer attribute group. Figure 20 shows a screen with the HtgClgSeq attribute group. Table 17: Main Sequencer Control Attribute Group Attribute Group Name Htg Clg Seq Function Coordinates the commands going to each of the cooling and heating control loops. Determines the Heat Cool Mode of the controller based on the current Space Temperature and the setpoints and then enables or disables the PI loops as required. Passes the commands to the actuator objects and monitors the override commands. Attribute Comments Fan Unocc Dmp Ovrd: The setup property that can be changed by the user. When True, it commands the damper to close when unoccupied and configured with a series fan, or when in heating mode and configured with either a parallel or parallel flow fan. Figure 20: Main Sequencer Attribute Group Example

42 42 The primary heating loop can be configured for either Position Adjust Output (PAO) (Incremental), Analog Output, Binary Output (normally open valve), Binary Output (normally closed valve), Electric 1-stage, Electric 2-stage, or Electric 3 stage. Dual heating (primary and secondary) supports the same box heating as supplemental heating and the same safety features as single source heating. Primary heating always goes on first, followed by secondary heating. The Secondary Heat Loop is enabled after the primary heat reaches 100 percent output for the specified saturation time. Heating stages must be wired in this order during installation. HtgClgSeq Figure 21 illustrates how the HtgClg Sequencer operates. Cooling Setpoint Space Temperature Cooling PI Cooling Command Enable Cooling Command Flow Controller Damper Command Delta P Value Damper PAO HW Sensor AI Heating Setpoint Space Temperature Primary Heat PI Heating 1 Command Enable HtgClgSeq Heating 1 Command Primary Heat Heating Setpoint Space Temperature Secondary Heat PI Heating 2 Command Enable Heating 2 Command Secondary Heat htgclgseq Figure 21: HtgClgSeq Function

43 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 43 Table 18: System Overrides Overrides Three override commands come in from the network. When active, these overrides change the commands sent to the output actuator objects. Override nviemergencyoverride [01MO17A or 01MS17] nviflowoverride [01MO16P or 01MO16F and 01AO162 and 01AO163] nvivalveoverride [01MO15 and 01AO152] Settings 0-EMERG_NORMAL (rmal operation) 1-EMERG_PRESSURIZE (Start the pressurize operation, open damper) 2-EMERG_DEPRESSURIZE (Start the depressurize operation, close damper) 3-EMERG_PURGE (Start the purge operation, open damper) 4-EMERG_SHUTDOWN (Shutdown all unit functions, close damper) 0-HVO_OFF (rmal control) 1-HVO_POSITION (Set damper position to the value in the percent field) 2-HVO_FLOW_VALUE (Control flow to value in the flow field) 3-HVO_FLOW_PERCENT (Control flow to value in percent field [this is a percent of the maximum flow setting]) 4-HVO_OPEN (Fully open the damper) 5-HVO_CLOSE (Fully close the damper) 0-HVO_OFF (rmal control) 1-HVO_POSITION (Set valves to the value in the percent field) 2-(t used) 3-(t used) 4-HVO_OPEN (Fully open all valves) 5-HVO_CLOSE (Fully close all valves)

44 44 Cooling Loop Cooling Loop objects are included in every heating configuration. M-Pro software makes all the necessary connections between these objects and other objects in the application and the profile. Table 19 describes the cooling loop attributes and Figure 22 shows a screen with cooling loop attribute groups. Table 19: Cooling Loop Attribute Groups Attribute Group Name HW Sensor AI Cooling PRACPI Continued on next page... Function Calculates the differential pressure from the DeltaP sensor. Enabled by the Htg Clg Seq when the space calls for cooling. Outputs commands to the Flow Controller to increase the flow when the Space Temperature is below the setpoint and decrease the flow when the space temperature is above setpoint. Attribute Comments attributes should be changed. Setup: Voltage DeltaP. Selects the correct linearization values for the integral Setra DP sensor. Slot: Defaults to 5 (the AI wired for the integral sensor). values should be changed in a typical install. Low Limit/High Limit: Limit the maximum change request that can be sent out from the object. Leave the values at default. Period: Default to 60 seconds (PI outputs a change once every 60 seconds). A typical room dynamic does not require the control loop run faster than this. Direct Acting: Defaults to Direct Acting (the required value when cold air is in the duct). PRAC Enabled: Defaults to True to enable the self tuning algorithm. If False, the user must manually tune the control loop by adjusting the Proportional Band (ncipbcool) and Integral Time (ncitintcool) through a LONWORKS network management tool. When PRAC is enable, initial values set in ncipbcool and ncitintcool are the starting points from which PRAC tunes. Input Type: Defaults to TempP (the PI is controlling a temperature loop).

45 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 45 Attribute Group Name (Cont.) Flow Controller Damper PAO Function Continued on next page... Calculates the flow setpoint and flow value, controls the P-Adaptive algorithm, and commands the dampers. Integrates (sums) the commands from the Flow Controller and sends a signal to the Damper Output objects. Attribute Comments Flow Coefficient: The constant used in the flow value calculation. This value is rarely changed. Autocal Period: The time between auto-calibrating the DeltaP sensor. When autocalibrating, the damper command is set to override closed. When closed, the value from the DeltaP sensor reads and is used as an offset that is applied to the subsequent DeltaP reading. When higher accuracy of flow reading is desired, set the time lower to autocalibrate more often. Period: How often the flow value is calculated and a new damper command is calculated. Sat Timer Preset: The time that the flow is at the MinFlow (cooling) before indicating that it is saturated low, which signals the HtgClgSeq to switch to heating mode. Max Dp Offset: If the DeltaP offset measured during the autocalibration is greater than this value, the sensor is flagged unreliable and the controller switches to a pressure dependent mode. This may occur if the damper stroke time is too small or if the damper is not fully closing during the calibration due to a bound damper or loose coupling. Max Velocity/Min ise Estimate: Used by the P-Adaptive algorithm. Min Pulse Width: Used by the P-Adaptive algorithm and sets the smallest output pulse that should be sent to the damper output. This number should equal the minimum pulse that the damper can accurately respond to. Polarity: Adjusting this with either a network management tool or Palm compatible balancing tool at ncidamperpolarity causes the actuator to turn in the opposite direction. This may be required where the damper operates as clockwise to close. Stoke Time: Sets the nominal stroke time for the actuator. For the VMA1200 using a 90 degree box, this value should be at least 90 seconds. Adjust ncistroketime with either a network management tool or in the TCV VAV application object before the application is downloaded to the controller. With this connection, Minimum Stroke and Maximum Stroke are not used. Min Pulse Width: Set to a value specific to the internal actuator and should not be changed. Reversal Delay: Causes the PAO to delay before reversing the actuator. Setting this value too small may cause the actuator to reverse excessively causing it to wear out sooner. Saturation Time: Delays the saturation status output from the Damper PAO object. Minimizes the toggling of the saturation output when operating near the end of travel in either direction. Update Rate: Hardware specific and sets the minimum resolution of the output signal. For the VMA1200, an update rate of 20 times per second provides a 50 millisecond resolution.

46 46 Attribute Group Name (Cont.) BO7 Damper Open BO8 Damper Close Function Controls the opening of the damper with commands from the Damper PAO object. This BO is not for general use with the VMA1210 or VMA1220. Controls the closing of the damper with commands from the Damper PAO object. This BO is not for general use with the VMA1210 or VMA1220. Attribute Comments Slot: Defaults to 7, may be changed if external actuator is connected to other physical outputs. Setup: Defaults to Timed Pulsed. Do not change. Polarity: Defaults to normal. Do not change. Slot: Defaults to 8, may be changed if external actuator is connected to other physical outputs. Setup: Defaults to Timed Pulsed. Do not change. Polarity: Defaults to normal. Do not change. Figure 22: Cooling Attribute Group Example

47 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 47 Flow Controller The flow equation is as follows: Flow = FlowCoefficient * BoxArea * P PickupGain1 + ( PickupGain2 * P) where P is change in pressure. If using SI units, the Flow Coefficient is 1289, Box Area is in square meters, and flow is in liters per second. If using rth American units, the Flow Coefficient is 4005, Box Area is in square feet, and flow is in cubic feet per minute. Primary/Secondary Heating Loops Heating Configuration Choose from the options in Table 20. Table 20: Heating Configuration (Question 5) Option ne (cooling only) Single Source (Primary) Dual Source (Primary and Secondary) Description points, properties, or logic are assigned for this answer. Single source heating assigns points, properties, and logic to support heating devices located at a single (primary) source. Single source heating supports incremental, proportional, duration, two position valves and actuators, and one to three stages of electric heat. Dual source heating assigns points, properties, and logic to control both primary and secondary stages of heat (box mounted heating devices and supplemental heating devices). This heating choice supports the same box heating and supplemental heating and the same safety features as single source heating.

48 48 Primary/Secondary Heating Choose from the options in Table 21 Table 21: Primary/Secondary Heating (Questions 5b and 5c) Option Position Adjust Output (PAO) (incremental) Analog Output Binary Output (normally open valve) Binary Output (normally closed valve) Electric 1/2/3-stage Description PAO heat performs incremental control using two triac outputs that drive the open and close actions of the actuator. With the correct stroke time entered, the duration and direction of travel is calculated to reposition the actuator based on proportional or position input. Analog Output heat provides continuous control driving an analog output. The AO receives a signal as a 0 to 100 percent and then spans this to produce a linear 0 to 10 volt DC output at the physical terminals. Binary Outputs (open or closed valves) support a single BO. The logic de-energizes the BO when the heating command is greater than the make limit, and energizes the BO when it drops below the break limit. These two cases are the same except for the way the BO object is initialized. Binary Outputs (open or closed valves) support a single BO. The logic de-energizes the BO when the heating command is greater than the make limit, and energizes the BO when it drops below the break limit. These two cases are the same except for the way the BO object is initialized. Electric heat applications contain logic to avoid operating the heat with inadequate flow (which could trip the optional thermal overload protection). VAV box manufacturers typically provide a pressure switch to lock out electrical heat in the absence of inlet static pressure. Pressure independent boxes enable electric heating when the measured flow is greater than the box electric heating minimum flow property or a box fan is operating. Below this value, electric heat is disabled. If either single or dual source heating configuration is selected, M-Pro software adds the objects and connections required for a primary heating loop. This includes the Primary Heat PRACPI as well as the objects required to drive the outputs for the selected type of heating. The heating type is selected during the Q&A session in M-Pro software. Dual source heating (primary plus secondary) generates additional objects that directly correspond to those created for primary heating, only these are associated with secondary heating. The HtgClgSeq enables the secondary heat loop after the primary heat reaches 100 percent output for the specified saturation time.

49 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 49 Depending on the configuration of the Primary Heating Loop objects, you may need to re-assign the Slot attributes of the output objects so they do not conflict with other objects. The desired mix of outputs may be more than the controller is designed to handle. For example, Primary and Secondary 3 stage electric heating requires six BOs, but only five outputs are available on the VMA1200. Figure 23 shows a screen with primary heating attributes. Secondary heating has the same attributes. Figure 23: Heating Attribute Group Example

50 50 Table 22: Primary/Secondary Heating Attribute Groups Attribute Group Name Primary/Secondary Heat PRACPI Primary/Secondary Heat PAO Continued on next page... Function Enabled when the HtgClgSeq calls for heat. Outputs commands to increase the heat output when the Space Temperature is below the active setpoint and decrease the heat output when the Space Temperature is above setpoint. Integrates (sums) the commands from indirect input from Primary Heat PRACPI through the HtgClgSeq object. Attribute Comments ne of these values should be changed in a typical install. Low Limit/High Limit: Limit the maximum change request that can be sent out from the object. Leave at default in a typical system. Period: Default is 60 seconds (PI outputs a change every 60 seconds). Leave at default for a typical system. Direct Acting: Defaults to Reverse Acting when controlling heat. PRAC Enabled: True enables the self tuning algorithm only for continuous type heating (Position Adjust or Analog Heating). The False setting is used for On/Off or staged electric heat because PRAC cannot tune in these applications. If False, the user must manually tune the control loop by adjusting the Proportional Band (cppropbandhtg) and Integral Time (cpinttimehtg) via the network management tool. When PRAC is enabled, these configuration properties are the starting points from which PRAC tunes. Input Type: Set to TempP (PI is controlling a temperature loop). Polarity: Adjust this with either a network management tool or a Palm compatible balancing tool causing the actuator to turn in the opposite direction. This may be required where the damper operates as clockwise to close. Stroke Time: t connected to a configuration property. The stroke time must be entered through the maximum and minimum stroke time attributes. Max Stroke: Set large enough to guarantee that the actuator fully opens or closes. Min Stroke: Set so the average of this attribute and the Max Stroke attribute is close to the average stroke time of the actuator. Min Pulse Width: Set to a value specific to the internal actuator. Reversal Delay: Causes the PAO to delay before reversing the actuator. Setting this value too small may cause the actuator to reverse excessively causing it to wear out sooner. Saturation Time: Delays the saturation status output from the Damper PAO object. Minimizes the toggling of the saturation output when operating near the end of travel in either direction. Update Rate: Hardware specific and sets the minimum resolution of the output signal. For the VMA1200, an update rate of 20 times per second provides a 50 millisecond resolution.

51 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 51 Attribute Group Name (Cont.) PAO PH1/PH2 PAO SH1/SH2 Primary/Secondary Heat AO AO PH/SH Primary/Secondary Heat BO1 BO PH/SH Primary/Secondary Heat BOx Continued on next page... Function BOs driven from the Primary Heat PAO and control the physical outputs that get wired to the actuator. BOs driven from the Secondary Heat PAO and control the physical outputs that get wired to the actuator. Provides continuous control driving an analog output. Controls the physical analog output that gets wired to the actuator. Driven by the Primary/Secondary Heat AO object. Sums commands from the Primary/Secondary Heat PRACPI through the Htg Clg Seq, which result in an effective command between 0 and 100 percent. BO driven from the Primary/Secondary Heat BO1 object and controls the physical output that gets wired to the actuator. One of these objects for each stage of the electric heat. Together with BO PEHx, works identically to the Primary heat BO1 (normally open) object. Attribute Comments Slot: Change this value to move them to other unused outputs. Setup: Defaults to Timed Pulsed. Do not change. Polarity: Defaults to rmal. Do not change. Slot: Change this value to move them to other unused outputs. Setup: Defaults to Timed Pulsed. Do not change. Polarity: Defaults to rmal. Do not change. Saturation Time: Delays a saturation signal to the Htg Clg Seq object when the output is either at its minimum or maximum value. The Htg Clg Seq uses this signal to enable secondary heating or cooling. Min Output/Max Output: Limit the output at either end. Max Output may be set lower than the Min Output if using a reverse acting valve. Make Limit/Break Limit: Specific to the Binary Output. t used here. Setup: Default is AO causing this object to work as an analog output. This same object type is used for binary and staged electric heat. Slot: Defaults to 1. Do not change. Setup: Set to BO to cause the object to work as a BO. Saturation Time: Delays a saturation signal to the Htg Clg Seq object when the output is either at its maximum or minimum. The Htg Clg Seq object uses this signal to enable secondary heating or cooling. Min Output/Max Output: Used when the object is setup for an AO (not used in this case). Make Limit/Break Limit: Edit to change when the heating switches between active and inactive. Together, these attributes provide some hysterisis so the output does not toggle when the command is near either limit. See Figure 24. Slot: Defaults to 1. May be changed to move to other unused outputs. Setup: Must remain On/Off Type. Polarity: Set to rmal if using BO (normally open valve) or Reverse if using BO (normally closed valve). See the Primary Heat BO1. Make Limit/Break Limit: Make Limit must be higher than the Break Limit.

52 52 Attribute Group Name (Cont.) BO PEHx/SEHx Interlock1/2 Function One of these objects for each stage of the electric heat. Together with Primary Heat/Secondary BOx, works identically to the Primary heat BO1 (normally open) object. Disables the heat from coming on, or shuts it off by sending the appropriate command to the connected output object if the measured flow is below the setup value set in the Box Elec Htg Min Flo attribute. Interlock 1 is for Primary Heat, 2 is for Secondary Heat. Attribute Comments See Primary/Secondary Heat BOx in this table. Box Elec Htg Min Flo: Set high enough to make sure that the heating element does not over heat. Analog Output Selecting Analog Output in the Q&A session configures the controller to provide continuous control driving an analog output. The AO receives a signal as a 0 to 100 percent and then spans this to produce a linear 0 to 10 volt DC output at the physical terminals. Binary NO or NC Output Selecting either Binary NO or Binary NC heating type supports a single Binary Output (BO). The logic de-energizes the BO when the heating command is greater than the make limit, and energizes the BO when it drops below the break limit. These two cases are the same except for the way the binary output object is initialized.

53 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 53 Make Limit/Break Limit Figure 24 shows the relationship between the BO and the Make and Break limits. See Table 22 for more information on the Make and Break Limits. Active Output Status Inactive Break Limit Command Percent Make Limit Figure 24: Make/Break Limits makebreak Staged BO (Electric Heat) Staged BO (Electric Heat) is one of three stages of electric heat can be selected. M-Pro software inserts one Primary Heat BOx object and one corresponding BO PEHx (Primary Electric Heat) object for each stage. These object pairs work identical to the objects created for the Binary NO Output case described above. Each Primary Heat BOx receives a parallel command from the Primary Heat PRACPI and integrates these commands to result in an internal effective command Figure 25. te: Substitute Secondary Heat PRACPI for the Primary Heat PRACPI in Figure 25 to generate corresponding secondary heating commands. Primary Heat PRACPI HtgClgSeq Interlock1 Primary Heat BI1 BO PEH1 Primary Heat BI2 BO PEH2 Primary Heat BI3 BO PEH3 PRACPI Figure 25: Heating Commands

54 54 By correctly initializing Make Limit and Break Limit attributes in each object, a staged sequence can be generated. The Primary Heat BOx then commands the corresponding BO PEHx to go either active or inactive. The Make Limit must be greater than the Break Limit (Figure 26.) Active Stage 3 Inactive Output Stage Active Stage 2 Inactive Active Stage 1 Inactive Break Break Limit 1 Limit 2 Make Limit 1 Break Limit 3 Make Make Limit 2 Limit 3 Effective Command (Percent) Figure 26: Multiple Break/Make Limits makebreak2

55 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 55 Room Sensors Thermostat Style/Product Choose from the options in Table 23. Table 23: Thermostat Style/Product (Question 6) Option Description TMZ Metastat The TMZ1600 room sensor allows for a minimum of 30 minutes and maximum of 4 hours of bypass time. The bypass time is only active when the VMA1200 is not in the OccMode. When the user presses the TMZ Temporary Occupancy button, the VMA goes into Bypass mode for the selected Bypass time. When the timer expires the VMA returns to Standby or UnOcc mode. Pressing the button prematurely toggles between TempOcc and UnOcc with the Red status light on the TMZ room sensor displaying the mode. Red = TempOcc, light = UnOcc. It takes a couple minutes for the TMZ and the VMA to synchronize operation of the red LED. If you try to toggle the button too quickly, it appears to the user as if you are locked out. As soon as the TMZ screen shows Temp Occ text, the user can press the button to toggle the occupancy mode. If the Temporary Occupancy button is pressed while the VMA is already in an Occupied mode, there is no effect and the VMA stays in Occupied mode and ignores the tempocc request. When the user presses the Temporary Occupancy button on the TE-6x00 room sensor (Metastat), the VMA goes into Bypass mode for the Bypass time. When the timer has expired, the VMA returns to UnOcc mode. Pressing the button resets the bypass time for the TempOcc. If the Temporary Occupancy button is pressed while the VMA is already in an Occupied mode, the bypass timer begins and if the VMA is released from the Occupied mode the VMA goes into tempocc until the bypass time has expired. The timer is programmed in ncibypasstime.

56 56 Thermostat Type Choose from the options in Table 24. Table 24: Thermostat Type (Questions 6b and 7) Option Remote Setpoint Description remote setpoint adjustment is provided with this option. points, properties, or logic are assigned. Warmer/Cooler Adjust This adds AI-2 with a default range of -3 to 3 C (-5 to 5 F). This can be scaled by the user. The warmer/cooler adjustment is active during all modes of operation (Occupied, Unoccupied, and Standby). Remote Setpoint This adds AI-2 with a default range of 18 to 30 C (65 to 85 F). This can be scaled by the user. The warmer/cooler adjustment is active during all modes of operation (Occupied, Unoccupied, and Standby). Sideloop Control Table 25: Sideloop Attribute Group The sideloop used by M-Pro software in VMA1200 Series controllers is typically used for humidity control. It is independent of the heating and cooling loops. The sideloop attribute objects are the same as those found for the heating loop (e. g., the sideloop equivalent of PAO SH1 is PAO SL1). Refer to the heating attribute group list in Table 22 for more information. te: As with the heating attributes, the possibility exists that the controller is unable to handle the desired mix of outputs (e.g., Sideloop 3 stage electric requires six BOs, but only five outputs exist for the VMA1200. Access the sideloop setpoint (nvisideloopsetpt [01AO84]) via the LonMaker software or an operator workstation. In the LonMaker software, it may be bound to an nvo. Refer to Table 25 for a description of the sideloop for the VMA1200 Series controller. Figure 27 shows a screen with sideloop attributes and Figure 28 shows the inputs and outputs of the sideloop. Attribute Group Name VoltAI Function The Process Variable for the sideloop. Measures the CO 2 level on the voltage AI. Attribute Comments Output Range Low/High: Defaults to a range of 0-100%. Adjust as required to meet the span of a specific sensor. Input Range Low/High: Defaults to a span of 0-10 volts which M-Pro software converts to ppm. Adjust as required to meet the span of a specific sensor. Slot: Defaults to 3. Do not change. Setup: Defaults to Voltage Input. Do not change. Output Offset: Defaults to 0. Adjust for sensor. Input Offset: Defaults to 0. Adjust for sensor.

57 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 57 Figure 27: Sideloop Attribute Group Example nvisideloopsetpt [01AO84] VoltAI Setpoint Sideloop1 [PRACPI] Output Command Process Variable Output Type: PAO AO BO Staged BO sideloop Figure 28: Sideloop Interactions

58 58 CO2 Control CO2 Ventilation Control Strategies Choose from the options in Table 26. Table 26: CO2 Ventilation Control Strategies (Question 11) Option Description Assigns points, properties, and logic to perform Demand Ventilation functionality. As CO 2 increases, this strategy increases the flow of the box as well. points, properties, or logic are assigned for this answer. This AI has been setup by M-Pro software to convert a 0-10 V input to ppm. The VMA1200 can only measure carbon dioxide levels (ppm) on AI3 with the appropriate transducer, so the Slot and Setup attributes should not be changed. The Output Range Low/High and Input Range Low/High attribute values may need to be changed to meet the specified span of a specific sensor. The [Output] Offset and Input Offset values can be also adjusted for a specific sensor. The Filter Weight attribute value may be modified to dampen a noisy signal from the sensor, but this modification typically is not required. See Table 27 for more attributes of the CO2 object. Figure 29 shows a screen with CO2 attributes. The measured value is used by the CO2 object and can be monitored on nvospaceco2 [01AI46]. Override the local value from the network from a remote carbon dioxide sensor by binding or writing a value to nvispaceco2. Table 27: CO2 Control Attribute Group Attribute Group Name CO2 Function Along with the Volt AI object, CO2 controls the carbon dioxide strategy used to adjust the minimum flow setpoints for proper ventilation. Attribute Comments Access adjusted values from the CO2 object through LonMaker software at ncimaxflow[cool] and nciminflowheat before the application downloads or by the network management tool during commissioning. CO2 Limit: Set in the profile. Used with the Offset to trigger the calculation of a differential value. Flow Adj Prop Band: Sets the sensitivity of the CO2 object. The smaller the number the larger the differential adjustment made to the Min Flow values and the faster the controller goes to maximum flow. Offset: Defaults to 150. When other objects trigger on the same CO2 Limit, this value provides a delay in applying the differential.

59 Variable Air Volume Modular Assembly (VMA) 1200 Series Controllers 59 Figure 29: CO2 Attribute Group Example CO2 Flow Reset The CO2 object compares the CO2 Effective Value measured by VoltAI to the CO2 Limit set in the profile. If the value is greater than the sum of the CO2 Limit plus the Offset, then this object calculates a differential value. The Flow Adj Prop Band sets the sensitivity of the CO2 object. The smaller the number, the larger the differential adjustment that is made to the Min Flow values and the faster the controller is forced to maximum flow. The differential is calculated as follows. ( ncimaxflow nciminflow) *( CO2EffectiveValue ( CO2Limit + Offset ) Diff = FlowAdjPropBand The differential is added to the nciminflow[cool] and nciminflowheat values from the profile. The adjusted values are output values, which are used by the Flow controller object. The adjustments are limited to the ncimaxflow[cool] and ncimaxflowheat values. The nci values can be changed in the profile object before the application is downloaded to the controller or by a network tool during commissioning.