If a vehicle is idling for 200 seconds or more, the existing trip will be deemed finished by MyGeotab and a stop will be created on the map. The idling duration after the trip will then become its own individual trip. Idling is measured when the device detects that the ignition is on, but the speed of the vehicle is zero. A stop is detected when the ignition is off. There is no way to change the logic for idling length.
In the new version of MyGeotab, if you navigate to Vehicle>(Pick a Specific Vehicle)>Driver Feedback, and turn on the option for "Enable Driver Identification Reminder", you can set a specific time frame. This time frame works in two way. First it defines the time limit the driver has to start the vehicle after he swipes in with his GO Key or NFC Key. The time frame also defines the amount of time that has to pass before the driver is disassociated with a vehicle.
For example, if I set this limit to 30 seconds, I must start the car within 30 seconds of swiping in as a driver. The device will also disassociate me as a driver 30 seconds after ignition has been turned off.