...
Modbus enables communication among many devices connected to the same network, for example, a system that measures temperature and humidity and communicates the results to a computer.
Modbus protocol and Teltonika
Teltonika supports two types of modbus Protocol:
...
The Modbus protocol module supports reading and writing to all valid Modbus registers from Modbus compatible devices.
Supported devices
Networks devices
...
All Teltonika routers and gateways has ModBus TCP master functionality to read data from other slave devices; Currently
As of 2020-03:
RUT955, TRB142 and TRB145 can be used to read data via ModBus RTU, since they has ModBus RTU master functionality;
...
RUT955, TRB142 and TRB145 can read ModBus slaves data using ModBus TCP and ModBus RTU protocols;
You can have more information in the link below:
...
https://wiki.teltonika-networks.com/view/Monitoring_via_Modbus
Vehicles Telematics devices
...
As of 2020-03, FMB640, FM63 and FMB125 support RS485, therefore they can support MODBUS Protocol, . But functionality it is not available, thus special development is required.