The logger sends the temperature as response for a command, so I need to send a comand too.
Can I configure something in the GPS to send every 5 minutes using RS232 a text string to get the response from the temperature data logger?
If you want more info about this to implement in your devices, let me know and I can send you info. Simple command, simple response.
Truck fleets with refrigerated trailers has this temperature dataloggers and can be a nice feature in you devices.