MODEL 722L. 2 Channel LCD Inductive Loop Detector Operation Manual

Transcription

1 MODEL 722L 2 Channel LCD Inductive Loop Detector Operation Manual Manual Number: February 2009 Published by Naztec, Inc. 820 Park Two Dr. Sugar Land, Texas Phone: (281) Fax: (281) Copyright 2009 Naztec, Inc All rights reserved.

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If you violate these Terms of Use, Naztec, Inc. may terminate your use of the Manual, bar you from future use of the Manual, and take appropriate legal action against you. Permitted Use You agree that you are only authorized to read, view and retain a copy of pages of this Manual for your own personal use, and that you will not duplicate, download, publish, modify or otherwise distribute the material on this Manual for any purpose other than to review product information for personal use or the use of a government or non-profit organization. No Commercial Use Users may not use this Manual for any commercial purposes such as to sell merchandise or services of any kind. You must obtain our prior written consent to make commercial offers of any kind, whether by advertisements, solicitations, links, or by any other form of communication. Naztec, Inc. will investigate and take appropriate legal action against anyone who violates this provision. 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You agree that any dispute involving these terms of use or this Manual will be heard in a court with jurisdiction in Fort Bend County, Texas. You further agree that the prevailing party in any legal action will be entitled to recover its reasonable attorneys fees incurred in connection with that action. If for any reason a court of competent jurisdiction finds any provision of these Terms of Use to be unenforceable, the remaining terms will continue in full force and effect. Entire Agreement These Terms of Use are the final and entire agreement between you and Naztec, Inc. with respect to this subject and replace any and prior or contemporaneous understandings or agreements, written or oral, regarding the subject matter. Any waiver of any provision of these Terms of Use shall be effective only if in writing and signed by an authorized representative of Naztec, Inc. MODEL 722L Operations Manual 1BFebruary 2009 Page 2

3 Table of Contents 1. GENERAL DESCRIPTION FUNCTIONS AND PROGRAMMING SENSITIVITY FREQUENCY SELECTION OUTPUT MODE : PRESENCE / PULSE / OFF / CONSTANT DELAY AND EXTEND TIMING PRESENCE RETUNE TIMEOUT VEHICLE COUNTING USER DEFINED CHANNEL LABEL TS1 / TS2 CONFIGURATION DETECT LEDS FAULT LEDS RESET EVENT LOGS SET FACTORY DEFAULTS FIRMWARE VERSION INSTALLATION INSTRUCTIONS SELECTING THE SENSITIVITY SELECTING THE LOOP FREQUENCY FIELD TROUBLESHOOTING LOOP INSPECTION THEORY OF OPERATION GENERAL CONCEPT IMPLEMENTATION On-board Power Regulation Loop Oscillator Precision High Resolution Counters Detection and Status Outputs LCD Display and User Interface Non-volatile EEPROM Storage SPECIFICATIONS ELECTRICAL SPECIFICATIONS OPERATIONAL SPECIFICATIONS PIN ASSIGNMENTS MODEL 722L Operations Manual 1BFebruary 2009 Page 3

4 1. General Description The Naztec 722L (P/N ) is an advanced two-channel micro-controller based digital inductive loop detector with a back-lighted front panel graphics liquid crystal display (LCD). The 722L meets or exceeds the NEMA TS1 and TS2 requirements for an inductive loop detector. For TS2, this loop detector supports the configuration requirements of a Type A, C, AC, or CC loop detector. The graphics LCD provides the user with a simplified and much enhanced interface for programming and control of the equipment. The LCD s back-lighting makes it readable even in low ambient lighting conditions. Programming of the 722L can be performed through a variety of menu driven display screens by using the two front panel mounted toggle switches. These spring-loaded toggle switches provide four (4) different user keys. They are labeled UP, DN, BACK, and SEL. During normal operations, status and activities of each channel can be monitored through the front panel display screen in addition to the Detect and Fault LEDs. Displayed parameters on certain status screens can be customized to the user s preference. Special diagnostic setup screens are also available for troubleshooting and to simplify initial setup for rapid deployment of equipment. Each channel can be individually programmed to operate in Pulse or Presence mode. In Pulse mode, a single 125 ms output pulse is produced each time a vehicle enters the loop. In Presence mode, a constant level output is produced while the loop is occupied. Alternately, a channel can be completely disabled by setting it to the Off or Constant mode. In Constant mode, a constant call is made at its Detect output regardless of whether the loop is occupied or not. There are 20 programmable sensitivity settings available that range from 3.5% down to a highly sensitive 0.003%. User programmed configuration parameters are saved in the on-board non-volatile memory. In case of a power interruption or failure, previous settings are retained and automatically re-applied upon power restoration. Programmable Delay and Extend features are provided with the 722L. Each channel can be separately programmed to have Delay only, Extend only, or both, or none. Delay can be programmed from 0 to 300 seconds, whereas Extend can be programmed from 0 to 60 seconds in steps as small as 0.1 second. Programmable Retune time feature is also provided. This time indicates the maximum time that a call will be held before re-tuning of the detector channel. Retune time may be programmed to Short, Med, Long, or the User setting. In the User setting, Retune time may be set from 1 to 120 minutes. Vehicle counting is supported and can be enabled on a per channel basis through the menu driven programming screens. The total number of vehicles counted can be viewed on the LCD. The count range is from 0 to 999,999. The 722L can be optionally configured to provide a separate pulsed Count output signal, available on separate pins from the Detect output. Each loop input is transformer isolated. High voltage transient suppression circuitry is provided to help protect against adverse transient electrical events. The detection outputs are optically isolated to maximize transient protection. In case there is no power applied to the detector, the output circuitry is designed to automatically place a constant call at the outputs. This failsafe feature conforms to the requirements of the TS2 standards. The 722L loop detector operates by sequentially scanning each channel to avoid cross talk from adjacent channels. In addition, there are eight user selectable loop frequency settings for each channel. This allows adjacent loops to be set at dissimilar frequencies and thus further reduces the chance of cross-talk. An added benefit from sequential scanning is a 50% reduction of power consumption by the loop oscillators. The 722L supports EIA232 serial communications per the requirements of the NEMA TS-2 standard. MODEL 722L Operations Manual 1BFebruary 2009 Page 4

5 2. Functions and Programming The Naztec 722L is initially programmed with a set of default operating parameters at the factory. These settings can be changed by the user. Front panel mounted toggle switches are provided for navigating through various menu driven screens for programming and status viewing. To program, invoke the MAIN MENU from a normal Status display screen, press the BACK key once. From there, use the UP or DN key to move the cursor to the desired item on the menu, then press SEL to select. If applicable, a sub-menu would appear for further choices. Use the same key sequence to select the desired item, or use the BACK key to go back. After power up, channels 1 and 2 are selected for display in a 2-Up screen (where two channels are displayed simultaneously). The displayed contents in this screen can be changed using the UP or DN key. For example, pressing the DN key one time will change the KHz display to the uh display. Pressing the DN key again will change it to the Cnt display. Pressing it one more time will change the format to a 1-Up screen, with channel 1 being the active current channel. To change channel while the 1-Up screen is active, simply press the SEL key. The 1-Up screen is an information-rich format which uses the entire screen to display information about the selected channel. Sensitivity Sensitivity sets the minimum level of change in loop inductance to which the unit will respond with a Detect status change. The level is expressed as a percentage of loop inductance change in response to the presence of a vehicle on the loop (delta L / L ). There are 20 individually selectable sensitivity settings for each channel. Listed below are the available settings and their corresponding percentage levels. From MAIN MENU > Program > Sens, the available SensLvl settings are as follows: Setting Sensitivity Remarks % Least sensitive % % % % % % % % % % % % % % % % % % % Most sensitive MODEL 722L Operations Manual 1BFebruary 2009 Page 5

6 Frequency Selection There are 8 individually selectable frequency settings for each channel. This feature permits the user to select dissimilar operating frequency of individual loops to reduce cross-talk between adjacent loop channels. The settings are numbered 1 through 8. The higher the number, the higher the loop frequency. The exact loop frequency will depend on the inductance of the particular loop. To help quickly determine an optimum frequency selection, the FREQ SELECT programming screen displays the instantaneous loop frequency as the selection is being changed. A Loop Frequency Stability graph is also displayed to indicate the quality of the current selection. Frequency settings of all other channels are also graphically represented as a reference. From MAIN MENU > Program > Freq, the available settings are as follows: Frequency Setting Frequency 1 Lowest Highest Actual frequency will depend on the inductance of the loop. Output Mode : Presence / Pulse / Off / Constant In Presence mode, the detection output is held active while the loop is occupied. In Pulse mode, the detection output is pulsed active for 125 ms when a vehicle enters the loop. For longer loops or side-by-side loops where multiple occupancies are possible, a pulse is generated for each additional vehicle entering the loop. In Off mode, the loop will not oscillate and the detection output will always be inactive. In Constant mode, the loop will not oscillate, but the detection output will always be active regardless of whether the loop is occupied or not. From MAIN MENU > Program > Detect, the available output modes are as follows: Mode Legend Remarks Presense PRES Pulse PULSE Off OFF DET LED off Constant CONST DET LED on Delay and Extend Timing Delay determines the length of time that the detection output will be delayed before providing an active output once a vehicle has entered the loop. Extend timing determines the length of time that the detection output will be held active after the vehicle has left the loop. Each of these parameters can be individually programmed from 0 to 300 seconds on a per channel basis. Time increments for shorter periods begin from 0.1 second and gradually increase as the period lengthens. Delay and Extend timing are only applicable to the Presence mode; Pulse mode overrides any Delay or Extend timing. While a delay is active, the front panel Detect LED will flash at a rate of 2Hz. Likewise, while an extension is active, the front panel Detect LED will flash at a rate of 4Hz. MODEL 722L Operations Manual 1BFebruary 2009 Page 6

7 From MAIN MENU > Program > Timing, the timing modes can be enabled or disabled. Selections are listed as follows: Mode None Both Extend Only Delay Only Legend NONE DEL+EXT EXTEND DELAY On the same screen, additional selectable fields are provided to change the amount of Delay or Extend time using the UP or DN keys. Presence Retune Timeout In case of a prolonged occupancy of the loop, the Presence Retune time determines the maximum time that a detect output call will be held before re-tuning of the detector channel. In effect, the occupying vehicle(s) will be tuned out. Retune time may be programmed to Short, Med, Long, or the User setting on a per channel basis. The Short, Med, and Long times are pre-set at the factory. In the User setting, Retune time may be set from 1 to 120 minutes. See table below for actual values. From MAIN MENU > Program > Retune, the Retune period can be changed. Selections are listed as follows: Period Legend Minutes Short SHORT 15 Medium MED 30 Long LONG 120 User Defined USER On the same screen, an additional selectable field is provided for changing the amount of user-defined retune time using the UP or DN keys. Vehicle Counting Vehicle counting can be enabled or disabled on a per channel basis. In addition, the accumulated count can be reset to zero using one of the programming screens. When enabled, the count is incremented as each vehicle is detected. The highest displayable total count is 999,999. To see the count, perform the key sequence as below: 1. From the normal (Status) display screen, press the DN key once. The KHz display is replaced by the uh value. 2. Press the DN key again. The uh value is replaced by the Cnt value. From MAIN MENU > Program > Count, the count mode can be enabled or disabled. Selections are listed as follows: Enable Count Disabled Enabled Legend NO YES Hint: If enabled in Pulse mode, all detected vehicles are counted. If enabled in Presence mode, a vehicle can be excluded from being counted if Delay Timing is activated, and if it vacates the loop before the Delay time expires. MODEL 722L Operations Manual 1BFebruary 2009 Page 7

8 On the same screen, an additional selectable field is provided for clearing the count on all or just the current channel. Clear Count None All Channels Current Channel Legend NO ALL CHAN User Defined Channel Label The label for each channel can be customized by the user. Up to 5 alphanumeric characters (upper and lower case letters included) can be entered for the label. Customized labels are saved in non-volatile EEPROM. From MAIN MENU > Program > Label, each character can be sequentially entered by using the UP or DN key to change, followed by the SEL key to select and move the cursor to the next character. TS1 / TS2 Configuration The Naztec 722L LCD Loop Detector can be configured to operate in the NEMA TS1 or TS2 mode. This primarily affects the behavior of the channel STATUS outputs. This configuration item is saved in non-volatile EEPROM. From MAIN MENU > Config, the mode can be toggled between TS1 and TS2 by using the UP or DN key. Press SEL key to make the selection. The selected mode will be applied to all channels of the module. Detect LEDs There is a Detect (DET) LED associated with each channel. Its ON or OFF state normally reflects the state of the channel s Detect output. When Delay and / or Extend timing is active, the LED will blink at different rates to indicate these respective conditions. Listed below are the states and blink rates with their associated meaning. State Meaning Off Detect output inactive On Detect output active 4 Hz Flash Extend is active 2 Hz Flash Delay is active Fault LEDs There is a Fault (FLT) LED associated with each channel. It is normally OFF if there had not been any fault conditions since the last reset or power up. Otherwise, the last encountered fault type will be indicated with a blink rate associated with the particular type of fault. Note that there may not be a currently active fault even if a channel s Fault LED is blinking. The blinking will persist until a reset or power cycle is performed. Listed below are the states and blink rates with their associated meaning. MODEL 722L Operations Manual 1BFebruary 2009 Page 8

9 State Meaning Off Normal operation/channel Off On CPU Failure 4Hz Flash Loop Shorted 2Hz Flash Loop open 1/2Hz FlashLoop inductance change > 25% Note: The FLT and DET LEDs will rapidly blink back-and-forth if the channel is in retune, or about to retune after a loop fault condition has been rectified. Reset An individual channel or the entire board can be reset with a simple key sequence. The channel(s) will be immediately forced into retune with the current configuration parameters. In addition, fault condition LED indications are cleared. However, any previous Log Events saved are not affected. From MAIN MENU > Reset, the current channel can be reset using the SEL key while the cursor is on Channel, or use the DN key to make another selection. The selections are listed below. Selections Current Channel Entire Module Channel 1 Channel 2 Legend Channel Module Chan1 Chan2 Event Logs Loop faults (events) are recorded and retained in non-volatile EEPROM. These fault conditions include Short, Open, and >25% Loop Inductance Change. Event logs can be viewed on a per channel basis. The most recent fault is displayed first. Logs can be cleared using the Event Menu. From MAIN MENU > Events, log events for the current channel can be viewed using the SEL key while the cursor is on ViewLog, or use the DN key to make selections relating to clearing of log events. The selections are listed below. Selections View Current Channel Clear Current Channel Clear All Channels Legend ViewLog ClearLog ClearAll Set Factory Defaults A set of default operating parameters was initially programmed into the non-volatile EEPROM at the factory. The factory defaults provide a basic, mid range operating condition for the detector. These settings can be restored through one of the menu screen selections. Note that setting Factory Defaults also clears all event logs and User Labels. From MAIN MENU > Default, the FACTORY DEFAULT menu screen is displayed, with the cursor on the selection entry under Restore Factory Default Settings:. To restore factory default, press the SEL key, then the DN key to change the selection. The selections are listed below. MODEL 722L Operations Manual 1BFebruary 2009 Page 9

10 Selections No Actions Restore All Channels Restore Current Channel Legend NO ALL CHAN After the selection has been made, press the SEL key to activate the command. Firmware Version Firmware version identification can be viewed on the LCD. From MAIN MENU > Version, firmware version of the micro-controllers can be viewed. Use the BACK key to return to the normal display screens. MODEL 722L Operations Manual 1BFebruary 2009 Page 10

11 3. Installation Instructions The 722L Loop Detector is pre-configured with a set of most common operating parameters, and can be ready to operate in some cases. Because loop sizes and configurations vary, channel sensitivity should be checked and adjusted to suit the particular installation for an optimum operating condition. Selecting the Sensitivity If sensitivity is set too low, the Loop Detector will miss calls. On the other hand, if set too high, it can issue false calls. However, it is generally accepted that a slight bias be given to the more sensitive side, i.e. it is better to have the sensitivity set slightly high than low. On the Sensitivity programming screen, below the frequency and inductance display is the Detect Signal Strength bar graph, which is actuated as each vehicle passes over the loop. Increase or decrease the sensitivity such that the signal strength bar graph falls between the two vertical hash marks for all desired vehicle types. For some loop configurations, this may not be easily done. In these cases, it is best to adjust for low-signal vehicles being near the left hash mark even if largesignal vehicles are above the right hash mark. Mid scale of the hash marks for an average vehicle is the optimum. (Note: The small tick mark to the left of the first hash mark is the minimum detection threshold level). Follow the steps below to set the sensitivity. 1. Press the BACK key to invoke the MAIN MENU 2. Use the DN key to highlight Program, then press the SEL key. 3. While Sens is highlighted, press the SEL key. 4. Default current channel is Channel 1. If a different channel is desired: a. Use the DN key to highlight the channel number. b. With each press of the SEL key, the channel number is incremented. c. When finished changing, press the DN key to return to SensLvl. 5. Below the frequency and inductance display is the detect signal strength bar graph, which is actuated as each vehicle passes over the loop. Increase or decrease the sensitivity such that the signal strength bar graph fall between the two vertical hash marks for all desired vehicle types. Mid scale of the hash marks is the optimum. (Note: The small tick mark to the left of the first hash mark is the minimum detection threshold level). 6. To change the sensitivity: a. Press the SEL key while the sensitivity number is highlighted. b. Use the UP or DN key to change the sensitivity number. c. Press the SEL key to select. If a vehicle is on the loop, the bar graph will immediately respond accordingly. 7. Use the BACK key to return to the normal display screens, or the UP key for another channel. To further help the user assess whether the settings are appropriate, a Detect Level History graph, followed by a scrolling Loop Frequency Stability graph is provided below the Detect Signal Strength bar graph. The Detect Level History graph is a time plot of the detect signal strength. In effect, it shows the signal strength profile associated with a certain vehicle passing over the loop. The scrolling Loop Frequency Stability graph provides an indication of the noise (or lack there of) level of the channel. See section 3.2 below for a further explanation of this graph. Selecting the Loop Frequency It is generally desirable to operate adjacent loops at dissimilar frequencies to minimize interference and cross talk. In case this becomes necessary, a special FREQ SELECT display screen is available to facilitate such selections and diagnosis. On this screen, a scrolling Loop Frequency Stability graph is displayed along with the current loop frequency in hertz. The graph changes in response to loop frequency changes as a result of vehicles passing over the loop, or just interference from other loops. Therefore, with no vehicle movements over the loop, a thin straight line graph indicates a very quiet channel. On certain installations, it may be necessary to change the loop frequency to move the channel towards this direction. Follow the steps below to set the loop frequency. MODEL 722L Operations Manual 1BFebruary 2009 Page 11

12 1. Press the BACK key to invoke the MAIN MENU 2. Use the DN key to highlight Program, then press the SEL key. 3. Use the DN key to highlight Freq, then press the SEL key to see the FREQ SELECT display screen. 4. Default current channel is Channel 1. If a different channel is desired: a. Use the DN key to highlight the channel number. b. With each press of the SEL key, the channel number is incremented. c. When finished changing, press the DN key to return to the frequency selection number. 5. To change the frequency selection number: d. Press the SEL key while the frequency selection number is highlighted. e. Use the UP or DN key to change the number. f. Press the SEL key to activate the change. 6. Use the BACK key to return to the normal display screens, or the UP key for another channel. Field Troubleshooting The following is a list of common installation related problems encountered in the field and possible corrective actions required. Intermittent Faults Verify good crimps on the loop lead-ins Verify that external lightning suppression devices, if present, are not faulty. They may need to be temporary removed for the test. Check that loop terminal connections at the loop termination panel in the cabinet are tight. Inspect the condition of the wire loop following the procedure described in Section 3.4. Detector Does Not Operate Verify that DC supply input at card edge connector position B is present and within specifications. Check that the External Reset line is not active (grounded) Make sure channel is not set to OFF or CONST, thus disabling the channel. See Section 2.3. Detector Is Missing Vehicles Increase channel sensitivity following the procedure in Section 3.1 Detector Is Generating False Calls Decrease channel sensitivity following the procedure in Section 3.1 Detector Is Generating Constant Call When Not In CONST Mode When the TS2 compliant 722L is installed in a type 170 cabinet (models 332 & 336 included), it might be necessary to disconnect the EIA-232 circuit of the 722L to resolve pin assignment differences. If so, simply perform the following: Locate shunt jumpers JP2 and JP5 (near transformer T4) on the main board ( ) Hand remove the pluggable shunt jumpers of JP2 and JP5. Note: These shunt jumpers are not available on REV D or earlier version PC boards. Please consult factory. Loop Inspection Poor loop detector performance can often be attributed to faulty loop condition or installation. The following is a very brief checklist that will allow the user to quickly inspect the loop. Described below is a list of items that will allow the user to perform a quick inspection of the loop. It is suggested that each loop lead-in be a twisted pair with shielding termination at the cabinet chassis ground. MODEL 722L Operations Manual 1BFebruary 2009 Page 12

13 1. Disconnect the loop inputs from the cabinet. 2. Meg the input to earth ground, they should be greater than 1 Mega Ohm. 3. Disconnect the loop shield from the cabinet ground. 4. Meg the shield to earth ground, they should be greater than 1 Mega Ohm. 5. Use a multi-meter to measure the resistance of each loop, they should be less than 4 Ohms. MODEL 722L Operations Manual 1BFebruary 2009 Page 13

14 4. Theory of Operation General Concept When a metallic body such as a vehicle passes over a wire loop installed in the pavement, there is a small change in the inductance of the loop. This inductive loop, together with an on-board capacitor, forms part of a resonant LC oscillator circuit, this slight change in inductance will result in a corresponding shift in the resonant frequency. This shift in frequency can be monitored and compared against a preset threshold for vehicle detection. By providing a selectable threshold of change, the detector can be adjusted to suit a particular installed application. Implementation The Naztec 722L loop detector contains functional sections that are responsible for on-board power regulation, loop oscillation, frequency counting and change detection, signal output control, LCD display and user interface, as well as non-volatile memory storage for configuration and event logs. There are two separate micro-controllers on each 722L. While one handles the LCD and user interface, the other is specialized as the detector engine. The combined processing power of the processors provides faster and more reliable performance over conventional designs. On-board Power Regulation The Naztec 722L loop detector contains on-board power regulation with reversed polarity protection. The module is operable from 26.5 VDC down to 10.8 VDC power input. Loop Oscillator Each channel contains its own LC resonant oscillator circuit. Capacitance and a precision op-amp comparator are provided on-board. When connected to the loop (inductor) on the street, the LC circuit is complete. The loop is actually coupled to the oscillator circuit via an isolation transformer. The purpose of the transformer, as its name suggests, is to electrically separate the oscillator circuitry from the loop in the street. This protects the on-board circuitry from any undesirable static discharges or transient events. It also permits lower grade loops to operate satisfactorily. The loop oscillator is designed to start or stop based on some controlling signals. Each oscillator can be independently turned on or off via the control signals driven by the microcontroller. In this fashion, the channels can be sequentially scanned, and thus avoiding the effects of cross talk from adjacent channels. While the LC components oscillate in a sine wave fashion, the output of the oscillator is squared up, and transformed into a digital signal prior to input to the counters. Precision High Resolution Counters To achieve a high degree of timing accuracy and stability, an independent external crystal oscillator is used as the measurement time base. A high-resolution clock counter, integral to the detector engine micro-controller, enables the use of this crystal oscillator clock source as the fundamental basis of time. Using a certain number of complete loop oscillation cycles as the period for counting, the high-resolution counter can be gated to accumulate the number of these clock cycles from the external crystal oscillator. Since the crystal clock period is a known quantity, the exact loop frequency can be determined. Detection and Status Outputs Detection outputs are optically isolated. In case there is no power applied to the detector, the output of the optical isolators will be off. A self-biased Darlington transistor arrangement will automatically place a detection call at the interface. In TS2 mode, the Status outputs continually transmit a pulse width modulated code for Channel Status Reporting as defined in the TS2 standard. MODEL 722L Operations Manual 1BFebruary 2009 Page 14

15 LCD Display and User Interface The LCD display is driven by the LCD micro-controller on the LCD Interface board. User key inputs, LCD status displays, programming menus are handled by the micro-controller. It also communicates with the detector engine to obtain current operating data for display Non-volatile EEPROM Storage In order to store basic configuration settings such as sensitivity, presence or pulse detect mode, delay and extend timing parameters, etc., non-volatile EEPROM storage is provided on-board. On power up, these settings are retrieved by the processor, and applied as operating parameters. A portion of the EEPROM storage is set aside for the event logs. MODEL 722L Operations Manual 1BFebruary 2009 Page 15

16 5. Specifications Electrical Specifications The following information provides a detailed set of electrical characteristics of the 722L Power Input: 10.8 VDC to 26.5 VDC 700 mv rms Max Ripple 100 ma Reverse Polarity Protection Oscillator Supply Voltage: 8 VDC +/- 5% Logic Supply Voltage: 5 VDC +/- 5% Loop Input Transients: +/-2000 V per TS2; +/-3000 V, 3 repetitions Operational Specifications Temperature Range (Operating): -37 to +74 deg C Relative Humidity (Operating): 5 95 % Self-Tuning: The detector is tuned and fully functional within 1 second after power up for most settings. Higher sensitivities may require more time. Temperature Tracking: The detector automatically compensates for frequency shifts due to changes in temperature. Loop Inductance Range: 20uH to 2000uH Loop Frequency Range: 10 KHz to 60 KHz Sequential Scanning: The loops are energized sequentially to eliminate inter-channel cross-talk Pin Assignments The following table details the card-edge connector pin assignments J1 Card Edge Connector PIN A- DC Gnd PIN 1- Inhibit 1 PIN B- +VUNREG PIN 2- Inhibit 2 PIN C- Ext Reset PIN 3- Addr 3 PIN D- Loop 1A PIN 4- Loop 1A PIN E- Loop 1B PIN 5- Loop 1B PIN F- CH1(+) PIN 6- Addr 0 PIN H- CH1(-) PIN 7- Status 1 PIN J- Loop 2A PIN 8- Loop 2A PIN K- Loop 2B PIN 9- Loop 2B PIN L- Earth Gnd PIN 10- Addr 1 PIN S- Count 1 PIN 15- Addr 2 PIN W- CH2(+) PIN 19- TXD PIN X- CH2(-) PIN 20- Status 2 PIN Y- Count 2 PIN 21- RXD MODEL 722L Operations Manual 1BFebruary 2009 Page 16