Hello,
To read data from the device, you need the AVL ID's of the data you want to receive. You can find the list of all of the FMB devices (including FM3001) AVL ID's, including OBD data, on our Teltonika wiki page here:
https://wiki.teltonika.lt/view/FMB_AVL_ID
Our devices mostly use the Codec 8 protocol to send data to the server. However if the AVL ID of the element you want to receive is larger than 255, then Codec 8 Extended will have to be used, since in Codec 8, the AVL ID size is 1 Byte, while in Codec 8 Extended, it is 2 Bytes. To enable Codec 8 Extended protocol, you have to set the Data Protocol in the configurator of your device, in the System settings, to Codec 8 Extended.
You can find the description of the Codec protocols on our Teltonika wiki page as well:
https://wiki.teltonika.lt/view/Codec
With the AVL ID list and Codec protocol description, you can start integrating them into your service.
I hope I've provided you with useful information. If you are satisfied with the answer, be sure to rate this answer!
If you have any questions, feel free to ask and I will be happy to help!