B&B Electronics MESR9xx manual From Serial Masters To Ethernet Master, Slave IDs Fixed

From Serial Masters To Ethernet Master, Slave IDs Fixed

Legacy Modbus slaves may have fixed IDs. To integrate these into a Modbus TCP network, a multiport MESR model (List here) can assign virtual slave IDs. For information on virtual slave IDs, see (list reference):

Figure 25. Scada to Slaves, IDs Fixed

Keep Serial Master, Add Ethernet Master(s)

In this scenario, the control system is a direct, time-critical serial system. The serial master must not be replaced, but Ethernet masters will need to have access to the serial slaves for monitoring or supervision.

Figure 26. Time Critical Control System

A sophisticated Modbus gateway (MESR921 or MESR922) can connect to the devices, with slaves going to one link and master another. The gateway allows communication between slaves and master, with a redirector aspect that lets the serial master keep on communicating with the slaves.