Interface between AB PLC and INCOM network

We have a AB PLC-5/40 hot back-up system with 1746 Remote I/O and would like to interface Cutler-Hammer Westinghouse IQ-1000 II, IQ Data Plus Motor Protection System Relays to the PLC. The relays can be connected on a Westinghouse Local Area Network called INCOM.

Is there any solution available for this?

An alternative solution by which these relays can be interfaced to a new stand-alone Allen-Bradley PLC is also acceptable.

By "AB PLC-5/40 hot back-up system", I presume you have a 1771-BCM (and possibly a -BEM as well).

If so, then just as all your 1746 Remote I/O are being handled by the -BCM, so will any other Remote I/O you put on the Remote I/O network. You refer to the Cuttler-Hammer devices as "relays". If they are just relays, wire them up to any remote I/O card+scanner system you want (1771-, 1746-, Flex I/O). They'll show up in the I/O image table of both PLCs, just as if there was only one.

Write the program as you would normally, and make sure that both PLCs have the same program.

Now, if you need to have the two PLCs sychronize data between them over the BCM high-speed serial link, well, that's a different matter altogether, and the subject of a different post.

INCOM is a proprietary twisted-pair serial LAN that Cutler-Hammer/Westinghouse use for networking their power management products. It's not particularly fast. Your baud rate options are 1200 and 9600.

There is a bridge module between INCOM and Modbus RTU. It's called NetLink. There is also a device called the MINT II RS232 translator which converts the INCOM network data to a stream of ASCII characters. I don't know if Cutler-Hammer publishes the details of the INCOM protocol. If they do, you might be able to use a BASIC module in the PLC5 to interpret the data from the RS232 side of the MINT II.

Your best bet would be to get someone from Cutler-Hammer familiar with the power management product line, and someone from AB familiar with the hot backup PLC5/40 in the same room at the same time to review your options.

John Rinaldi at Real-Time Automation in Wisconsin has built IMPACC protocol application programs that will interface a MINT-II box to an Allen-Bradley slot-mounted interface module.

Their website shows a version that runs on the 1746-BAS module, as well as one for the (ugh, not my favorite) 2760-RB module.

http://rtaautomation.com

But the 1746-BAS doesn't have some of it's extended functionality (M-files) when you put in in a remote chassis with a 1747-ASB, so you might go for the 2760-RB module in a 1771-A1B chassis.

It won't be cheap, it might not be easy, but if you need to interface these two systems this is a product you may wish to investigate.

I am not familiar with this product, but we have had much success interfacing GE Multilin Motor Management relays to both SLC 500 and PLC 5 processors. They communicate using Modbus protocal. We use Prosoft modules to communicate with them.

Here are some web links in case you are interested.

Multilin 239 Motor Protection Relay

http://www.geindustrial.com/products/brochures/239.pdf

Multilin 469 Motor Management Relay

http://www.geindustrial.com/products/brochures/469.pdf

Prosoft Modbus Communications Module (3100-MCM)
and Modbus Communications Module (3150-MCM)

http://www.psft.com/download/Datasheets/English/3100MCM.pdf