Communicating between plc's with different IP's

[plcaholic 0]

I am trying to get produced and consumed tags set up between 2 1756 racks with different ip's.

The 1st rack has an ip address 172.28.6.3.

The 2nd rack has an ip address of 10.81.105.8.

Would this be as simple as adding an EN2T card to one of the racks and setting the ip of one onto the same network? Or is there a better way to do this?

[Michael Lloyd 85]

Adding a second NIC would work. It probably wouldn't be any more expensive that adding a router and getting that programmed to bridge the two networks.

Just curious, why Produced / Consumed instead of using a Message block

[plcaholic 0]

I am just more familiar with produced / consumed tags since all of our plant is set up in this way. So trying to keep everything consistent for troubleshooting is the main reason. How could this be done with just using a router?

[Michael Lloyd 85]

That makes sense. I've never been a fan of them but if you're already invested, why not.

Routers are outside of my skillset but the router, when programmed right, can bridge two different networks (route one to the other). If you have an IT department check with them

[Joe E. 251]

If this were our system, we would have to add a second network module since our IT folks lock down all devices more sophisticated than an unmanaged switch. We have a lot of 1756-ENBTs in service, but I know they're getting closer to end of life so we would probably use an -EN2T. That can support either MSG or produce-consume.

We typically use MSG instructions since our PLCs span a wide range of versions and types (including MicroLogix, SLC 5/04, PLC-5s, and various Logix 5000s). The one time I tried to set up produce-consume, I couldn't because the two PLCs were such different firmware versions. One was a 1756-L55 that can only go up to v16 while the other was a 1769-L30ER that could only go back to v18 (I think...). I could add the -L55 to the -L30ER project, but not the other way around. I was going to try to add the -L30 as an older model PLC that was available just to see if it would work, but that project suddenly dropped off of the radar screen and became a lot less important. When I went back to it, I just used MSG instructions.

[Michael Lloyd 85]

Agreed. You control the system vs IT controlling the router

[pcmccartney1 140]

Possibly use a Red Lion DSP?