This is an example of a use-case for the G100 in monitoring refrigeration trucks. Setup is the same for a Dart. 

The truck is required to be tracked as per usual, with the additional requirement for logging of run hours of the refrigerator, and the refrigerator status (OFF/ON) to be displayed in the live viewer. This could easily be applied to any use-case where a secondary device requires logging or display in the live viewer. 


The G100 is wired into the truck battery and ignition as usual.

  • Pin 24 (RED)     to the positive terminal
  • Pin 12 (BLACK) to the negative battery terminal
  • Pin 23 (WHITE) to the ignition

The refrigerator battery is connected to the following leads on the harness

  • Pin 16 (BLUE)    to the positive terminal. This is the pin for digital input 2. Any digital input pin could be used. 

See the G100 Harness Definition for more information. 

Once this is set up, the inputs need to be mapped and bias resistors (pull up/pull down) need to be set.


In the Digital Input 2 tab. (Or whatever digital input you want to use) These settings are used.

Digital Input - Input 2: So digital input 2 will be set high when the refrigerator battery is on, allowing state changes to be seen and logged in Telematics Guru

Bias Resistor - Pull-down: We want the bias resistor set to Pull-down. This pin will be pulled down to ground (held LOW) when no input is applied. When the fridge is turned on, input 2 receives a HIGH signal due to the voltage now being supplied from the running fridge battery. 

With this setup we can detect the change in the input. 

Battery OFF = Input is pulled down and reads LOW, 

Battery ON =  Voltage is suppled and Input reads HIGH. 

Active Level - High:  The battery turning on is logged as active (1). 

Log On Active/Log On Inactive/Upload On Inactive: Setting uploads on active and inactive will display the status of the refrigerator in Telematics Guru quickly, rather than waiting for heartbeat or trip uploads. In this case we want to know the status of the refrigerator when the truck is parked, so we set Yes so the G100 uploads whenever the refrigerator is turned on or off. 

Config1: Debounce time - stops multiple events registering. If the voltage seen at the input pin is likely to fluctuate during start up, set this to a reasonably high value (0.5 - 2 seconds). 

In Telematics Guru

Digital input 2 is named the Fridge Motor, and set to display in trip and on the live viewer. To be able to get event reports for fridge run times, we must create an event, in the Admin -> Event Types Menu, and set this in the input mapping. 

The event type will now display in the live viewer: