Thank you for your query,
Could you describe your solution in more detail?
To identify your trailer you could use ELA ID beacons, which would send their IDs to the device in the trailer head, this data then could be sent to your server and further implementation could help you to identify, which trailer is connected.
ELA ID COIN product can be found in our website:
FMB trackers are capable of supporting BLE sensors and beacons using the new experimental firmware version, to test this please contact your sales manager,
Hope this helps,
If you have further questions inform us,