Modicon 984-A141 Comms to ControlLogix

[Mick Hughes 0]

Hello all, My first post on this site, so excuse me if I break protocol (sorry about the bad pun). My customer has a Modicon 984-A141 stand alone processor on site. They are implementing a new machine but want to keep the existing running. The new machine has a ControlLogix processor. I am going to parallel wire or add connectors to the existing PLC panel to pick up the required field signals, modiying the existing and new PLC code accordingly. My life would be some much easier if I could pass data between the controllers. Has anyone done this? I'm researching the Schneider/Modicon 174 CEV 300 20 card - hopefully this will suffice. Thanks, Mick

[Crossbow 295]

There are no Modicon devices which can easily communicate with Allen Bradley. In the years I worked with them, my best option was cards from Prosoft, which go into the AB rack and add Modbus serial or Modbus Plus. But I haven't touched a Modicon since 2002 (and that's not a complaint!).

[Mick Hughes 0]

Thanks! I talked with Modicon/Schneider technical support and they said it's no problem as long as the ControlLogix has the ability to talk Modbus TCP... I'll keep on digging!

[aggattapauer 2]

Hi Mick. You can easily talk with any Allen Bradley PLC.......yes.....now. But if you have Unity processors. Because of your Modicon 984 you may communicate only in Modbus RTU protocol and only with Prosoft module installed on AB PLC. CEV device is a gateway Modbus TCP <--> Modbus RTU (RS485). If in the AB PLC configuration you have an Ethernet module supporting Modbus TCP, you might connect the CEV to an rs485<-->232 converter and then to the Modbus port of Modicon 984. Allen Bradley will be the master and Modicon the slave. Otherwise you need the MCM....... Prosoft module installed on AB rack, so you can connect the Prosoft module to the converter and that one to the Modicon Modbus Port.

[Crossbow 295]

As I said, the old Modicon doesn't offer AB comm options. You need third party devices like the Prosoft modules. And by default AB does NOT have Modbus/TCP, they use Ethernet/IP for their Ethernet protocol.

[Mick Hughes 0]

Thanks chaps!!! I think the consensus is to use one of the third parties - Prosoft, Prolinx Gateway, Advantech or Westmoro - are the players I have discovered so far - THANKS FOR YOUR HELP!!!!