How many devices can be connected on MODBUS TCP (Ethernet) Network?


Thread Starter

Ajit Yeole

I want to know what are the maximum number of devices a MODBUS TCP Driver / I/O Server can communicate with? We will be using Wonderware InTouch on the SCADA Side and Modicon TSX Micro PLC with ETZ Module (Total 426 nos.) on the RTU Side.

Ganesh Okade

For Ethernet any number theoreotically. But make sure you divide your 426 PLCs properly using switches and hub if you do not want to clog your network!

Ganesh Okade
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Unlimited, in theory. Practically you will need to determine how often you must update the information, how much information will come from each device, how many devices off each switch or hub, etc. If you need faster performance, then simply add an additional ethernet card to your pc and divide the network into two different subnets. Note that the switch closest to the pc, or the pc itself in the scenerio you described, will most likely be the most limiting device on your network performance.