Quantum MODBUS Plus Communication


Thread Starter


I am currently working on PLC5 to ControlLogix migration project.
Currently PLC5 communicates to Quantum PLC using SSL X-Link converter. But as part of this project I am planning to remove X-Link converter and install Prosoft Modbus Plus (MVI56-MBP) module in CTRLX rack. so that both PLC can talk to each other.

My question is....What kind of updates/changes required in Quantum PLC so that Quantum PLC can read or write from Prosoft module?

it looks like Quantum PLC is master.
Good morning,

As far as I know, the Quantum processors (models 434, 534 and 113-03 which I've worked with, anyway) natively communicate with Modbus Plus. So if the Prosoft module you're referring to adheres to the Schneider-Electric Modbus Plus standard, I think it should work.

Mind you, I've only had Quantum processors communicating with other processors, or with Modbus Plus expansion cards in IBM compatible PCs. (Such cards as the PCI 85 and SA 85, using Cyberlogic MBX drivers, under Windows.)

You said that you thought that the Quantum PLC is the master. Well, it can be the one to initiate communications, but in a Modbus Plus setup, any device (or node) which has the "token" can request data from, or send data to, another node, as far as I understand it.

There should be plenty of information on the Schneider-Electric website explaining how Modbus Plus works, as it's quite an old means of communication. (Old doesn't mean "no good"; it's a little slow, at only 1 megabit, but when set up correctly, it's very robust.)

Pardon me for being verbose, and I hope this answers your question. :)
Kind regards,
Roger V.