We will ne using three (3) compactlogix PLC's communicated through Ethernet Gateway. These PLC's will the be communicated with a PC through Modbus RTU gateway. Can we use 460ETCMC Gateway in this application? To communicate the Compactlogix PLC the PC which will have a Factorytalk application.
In theory, you could use the Modbus gateway to map Modbus registers to CompactLogix database tags, then use a third-party OPC provider inside FactoryTalk to read and write those Modbus registers.
I cannot think of a good reason to do so, though, since FactoryTalk View includes RSLinx Enterprise, which has stable, fast, optimized access to the CompactLogix tag database over Ethernet.