1. Applicability Geo-Fencing with the SkyRouter (TN034) All 4200, 4400, and 4550 models with required firmware upgrade. For the 4200/440 the required firmware is 4.02.02.07 or 6.00.01.00 or newer and for the 4550 the required firmware is 6.00.01.00 or newer. 2. Background Information This TechNote covers the setup and operation of the SkyRouter s geo-fencing feature. It also explains how the geo-fencing feature interfaces with Ctek s Automation application and how Automation can be used to enhance and extend the geo-fencing capabilities. Geo-fencing application models examined include the native web browser interface (Section 3), an SMS managed interface (Section 4), a physical model based on a switch and LED indicator (Section 5), and a control model based on the SkyRouter s XML interface (Section 6). Figure 1 - Various Application Models
3. Geo-Fencing Setup Geo-fences are defined on the location source page. Geo-fences are also enabled/disabled from this page. In the next section, an alternative method of enabling/disabling geo fences using the Automation application is described. 3.1 Location Source Screen System Location Options Panel The Location Source screen contains the following fields and controls. See Figure 1 below. Location Source GPS (Internal) Use the inbuilt GPS subsystem [Require for Geo-fencing] Use Lat/Lon Below User defined location for stationary installations Latitude Latitude expresses as a decimal value for user defined location (Example 42.83169). User defined locations cannot be geo-fenced. Longitude Longitude expresses as a decimal value for user defined location (Example -77.93366). User defined locations cannot be geo-fenced. Reset Interval The interval in minutes at which the GPS subsystem will be reset if a fix cannot be obtained. 3.2 Location Source Screen Fence 1&2 Configuration Panels Mode Options are Enabled, Disabled, or Automation Control. Enabled and Disabled control the state of the fence with regards to setting up a fence using the web interface. The Automation Control setting makes the fence available for use with the Geo-Fence- Set automation function described in section 4.1 below. In the Automation Control mode, the fence can only be enabled or disabled through Automation Control. Fence Type Options are Fence In or Fence Out. The Fence In setting generates an alarm when the device leaves the defined area. The Fence Out setting generates an alarm when the device enters the defined area.
Coordinate Source Options are GPS or User Defined. GPS will use the current GPS provided position as a center point of the fence, User Defined will use the user provided Lat/Lon for the fence. Geo-fences constructed with MODE=Automation Control must use the internal GPS. In this case the center of the fence will be the coordinates being received from GPS at the moment that the fence is enabled through Automation Control. In the case where MODE=Enabled or Disabled a user defined coordinate set may be used as may the internal GPS coordinates. Latitude/Longitude The User defined values describing the center point of the fence. Decimal format required. See Coordinate Source above for a discussion of the restrictions for various modes. Radius (mi) The field specifies the radius of the geo-fence being created in miles. Decimal fractions e.g. 0.4 are allowed. Ctek recommends that the fence radius be greater than 0.2 miles to avoid false positives.
Figure 2 - Location Setting Page Geo-fence #1 and geo-fence #2 can be configured to describe areas that are either geographically overlapping or geographically mutually exclusive where either fence can be of type fence In or Fence Out. In Figures 1 and 2 below we see some examples of two-fence constructs. In Figure 2 Alarm O triggers when the device enters the Fence Out area and Alarm I triggers when the device leaves the Fence In area. In Figure 3 Alarm O1 triggers when the device leaves the inner fence and Alarm O2 triggers when the device leaves the outer fence.
Figure 4 - Fence Models Figure 3 - Fence Models 3.3 Geo-Fence Alarm Indications Geo-fence alarms (violations) are presented as digital signals (alarm/clear) on Automation input pins. Typically, a virtual input pin will be used. The state of the pin can then be used to send SMS and email alarms as defined in the Automation Unit configuration page. In addition, the geo-fence alarm pin can be connected to a physical output pin(s) to set visible or audible alarms if desired. Figure 4 below shows a typical geo-fence alarm pin set up. In the example shown the fence violation alarm is configured to repeat 3 times at 30-minute intervals.
Figure 5 - Geo-Fence Alarm Pin 4. Extending Geo-Fencing Capabilities Using Automation Note This section assumes that the user is familiar with Ctek s application note APN007 that documents the Automation Control application 4.1 The Geo-Fencing Control Function The Automation Control application can be used to enable/disable the geo-fences using SMS commands, the Automation Control Panel, or the SkyRouter s XML interface. When using Automation Control Define the fence type. Define the fence radius. The longitude/latitude coordinates are defined by the system when enabled by Automation Control using the SkyRouter s current position. The fence will not enable if the device is in motion or does not have a GPS ready indication. The control methods are based on assigning an action function (Geo-Fence-Set) to one or more Automation programs, which in turn can be assigned to control pins of a geo-fence. The syntax of geofencing specific control function is: Geo-Fence-Set <fence #> <enable: 1/disable: 0> Important Programming Note:
TN034 - Geo-Fencing with the SkyRouter When enabled, upon the SkyRouter getting its center coordinates the fence s ON status is set and OFF is cleared. If the SkyRouter cannot establish the center point of the fence within 15 minutes, the OFF status is set and an SMS/email alarm indicating that fence is not enabled to be generated. However, the program will continue to try to establish the fence until you run the program to shut the fence off. If the 15 min. timer has expired and the fence could not be brought up, turning the fence off with a program will reset the timer for the next start attempt. A power cycle or restart of the unit with an active geo-fence will automatically re-enable the geofence when the GPS gets a fix, and initiate a geo-fence on status. This is done since the unit may have been moved after it was powered down. A geo-fence that has been disabled, or has never been enabled will behave in a similar fashion. 4.2 A Complete Geo-Fence Application Managed by Automation Control This example application makes use of the following virtual automation pins: Input 1 [digital] Set when geo-fence 1 is violated, reset when geo-fence is activated or deactivated Input 2 [digital] Used as a toggle to execute the Geo-Fence Set function for both On and Off. Input 3 [digital] Geo-fence ON status indicator pin. This pin is used to initiate a text message when the geofence has been successfully enabled. Input 4 [digital] Geo-fence OFF status indicator pin. This pin is used to initiate a text message when the geo-fence has been successfully disabled. Output 1 [digital] Executes the activate geo-fence 1 programs. Can be set using SMS (see TN009). Also appears on the control panel for simple web interaction. A simple logic diagram follows: Figure 6 - Fence Logic
See Figure 5 above TN034 - Geo-Fencing with the SkyRouter Setup for Input 1 Setup for Input 2 Figure 7 - Input Pin 2 (Enable Command)
Setup for Input 3 Setup for Input 4 Figure 8 Input Pin 3 (Status = On) Figure 9 - Input Pin 4 (Status = Off)
Setup for Output 1 Figure 10 - Output 1 (Activate/Deactivate Control Pin) Activate Program Figure 11- Activate Program
Deactivate Program Figure 12 - - Deactivate Program 4.3 Theory of Operation Preface First, carefully review the notes found in section 4.1 above. Especially note that the operation of input 3 and 4 is not persistent, meaning that it will only indicate the condition of the geo-fence until the next restart/power-fail. Upon recovering from a restart/power-fail the fence will be activated or deactivated based on the last command received but status pins 2& 3 are no longer valid. The pins should be viewed as pulses, showing the status of fence activation only during the current restart/power-up cycle. Activation When Output pin 1 (Figure 8) is set to on, it toggles Input pin 2 and the Arm Program is executed. The program attempts to start the geo-fence. The fence will be started if, and only if speed = 0 and the GPS ready signal is present. As noted above the Activate Program will attempt to establish a fence for 15 minutes based on these requirements. If the program is successful, it will set the fence status ON pin (input 3) which will notify the user via SMS/email that the fence is active. At the end of 15 minutes of attempting to establish a fence, if the operation is not successful, the fence status off pin (Input 4) will be set to indicate via SMS/email that the requirements for a fence could not be met. However, the activate program will continue to attempt to establish a fence until the next time the Deactivate Program (Figure 12) is executed. Deactivate When Output pin 1 is set to off, it toggles Input pin 2 and the Disarm Program is executed. If the program is successful, it will set the fence status OFF pin (input 4) which will notify the user via SMS/email that the fence is active.
4.4 SMS (Text Messaging) Control With the set up described above geo-fence # 1 can now be activated at the units current coordinates, using a previously defined radius size, by using the text command ===SET o 1 1. See TN009 for additional detail. Upon successful fence activation or unsuccessful activation at the end of the 15-minute timer, a status SMS will be sent to the phone numbers specified in the unit configuration screen. Likewise, the fence can deactivated using the text command ===SET o 1 0 and the user will receive status via SMS/email. 4.5 Automation Control Panel In addition to controlling the geo-fence from the Location Source screen the following optional control panel mechanisms are now available as a result of the Automation Control design described above. Figure 13 - Control Panel 4.6 XML Control Another alternative method of activating and deactivating a previously defined fence using the Automation set up described above is through the SkyRouter s XML interface. Using the XML messaging structure defined in APN005, output pin 1 can also be set and reset, and status values defined for input 2 can be obtained.
5. Managing a Geo-Fence with a Switch and LED 5.1 Enable and Disable With a few modification on the design described in section 4, a SPST switch connected to the SkyRouter s relay input pin can be used to arm the geo-fence and an LED connected to the SkyRouter s relay output can be used to indicate the armed/disarmed status of the fence. The set up for a switch and single LED implementation is described below. This example application makes use of the following virtual automation pins: Input 1 [digital] Set when geo-fence 1 is violated, reset when geo-fence is activated or deactivated. Alarms violations via SMS and email Input 2 [digital] Connected to the SkyRouter s relay input. Used to arm/disarm the geo-fence Output 1 [digital] Connected to the SkyRouter s relay output and is used to light the armed LED. 5.2 Switch/LED Enabled The Programs Figure 14 - Switch Activation
Figure 15 - Switch Deactivation 5.3 Switch/LED Enabled The Inputs Figure 16 - Fence Violation Alarm Pin
Figure 17 - Fence Switch Control Pin 5.4 Switch/LED Enabled LED Driver Output Figure 18 - LED Control 6. Automation Control Extensions The logic described in this TechNote details a number of basic geo-fencing implementations. With Automation Control AND & OR logic, a more complex mechanism could easily be developed that would support a combination of SMS, Control panel, and physical (switch) controls.