We do not have any converters to SNMP and cannot advise on how to implement the interfacing of SNMP traps to our devices over RS485.
We can only offer the link to a software that allows monitoring the Modbus commands transferred across the RS485 between our interfaces and the Modbus master (our software tool ModTool). The software can be used to test the Modbus communication.
The software can be downloaded from following article:
ModTool Communication with our Products