How do Modbus registers map to OIDs?
The Babel Buster SP functions as a stand-alone server device. It can be configured as a Modbus RTU master or slave. It is also concurrently a Modbus TCP client and server. When the RTU side is configured as the master, it automatically polls the various Modbus devices periodically. The TCP client, if used, will also automatically poll various Modbus TCP devices periodically. This data is stored in local registers in Babel Buster SP. This data is simply saved, waiting for SNMP to Get the data. When SNMP does a Set, this results in data being written to the Modbus device once per update, or repeatedly if configured to do so. To begin the process of mapping Modbus to SNMP, you need to obtain documentation from the device manufacturer telling you which registers contain what data. You will also need to see that baud rates are matched, and you know or can set the RTU slave address (or unit number, comparable to a shortened IP address). There are technically four types of Modbus “registers”;
