Hello,
Thank you for your question,
The value of iButton/RFID can be saved throughout the single trip, if "Trip" scenario is used, in the configurator Trip / Odometer section you should be able to find "Advanced Trip Settings" and select Remember iButton - Enable.
Please note that iButton value is saved until the ignition is OFF and scenario ends according to the set up of parameters.
Hope this helps,
Regards.