The MODBUS server that is built-in implements MODBUS TCP. MODBUS is a request / response protocol and is not as efficient as other protocols. That being said, MODBUS is widely used.
Since the JNIOR is security conscious, we have a login option built-in for applications where a custom function command can be implemented and sent. The Login is set to true by default. If a login cannot be sent, set the ModbusServer/Login registry key to false and reboot the JNIOR.
INTEG can write custom applications to communicate with other MODBUS devices across any of the MODBUS protocols. MODBUS RTU over RS-485 can only be used on the JNIOR 410. The JNIOR 410 is the only model with RS-485 capabilities.