Automation Direct C-More and AB Compactlogix connection

I have a compactlogix L32E. I am connecting about 20 Automation Direct C-More touch screens to it. The current PLC Protocol I am using to connect is the "Allen-Bradley EtherNet/IP Client Tag-Based (Control/CompactLogix)".

Some times I lose connection for a couple of seconds (5-10). I am looking for a way to make this connection more reliable.

The C-More also allow one to connect using the "Allen-Bradley EtherNet/IP Server (Generic I/O Messaging)".

Does any one have experience with both of these types of connection protocols and know which one is faster/more reliable?

Allen-Bradley EtherNet/IP Client Tag-Based (Control/CompactLogix)

or

Allen-Bradley EtherNet/IP Server (Generic I/O Messaging).

There is a limit on how many connections an L32E can have (I believe it's 32). I don't know how many connections a C-More takes, but I know that a Panelview Plus takes up to 5, meaning any more than 6 of them and you'll risk losing reliability. Keep in mind almost every sort of connection counts as well. Connecting to it with your laptop over Ethernet is a connection as well.

My guess is you're simply hitting your limit on connections and the processor can't handle it. If this is the case, you'd need a Control Logix series processor to have more reliable performance.

The 1769-L33ER compact logix processor should work for you. Hopefully Ken Roach will chime in and Explain the difference. If not contact your local AB folks they should be able to help.

We have a pretty handy whitepaper on using C-More with AB PLC's over at the AutomationDirect Technical Support site.

It should help with most of the common issues with getting the two components to work together.

If you still have issues, give Technical Support a call at 1(800) 633-0405 or email us. It's free.

Thanks Guys, these answers help, I now have a good idea of where to go with this to speed up my connection.

icky812 said:

We have a pretty handy whitepaper on using C-More with AB PLC's over at the AutomationDirect Technical Support site.

If you still have issues, give Technical Support a call at 1(800) 633-0405 or email us. It's free.

Click to expand...

Like the AB support...

I agree that the user is probably encountering a CIP Connection capacity limit for the controller, but it's also possible he has different problems on his network or with his controller.

CIP capacity limits usually manifest themselves as refused connections, as in "it works when we have 15 panels connected, but the 16th panel does not connect". When a connection drops and then re-establishes, it suggests a timeout.

The embedded Web page for the Ethernet module will give him some good diagnostic information about how many connections are in use simultaneously. The RSLogix 5000 Task Monitor Tool is another way to get that information.

20 HMI units on a CompactLogix is far more HMI loading than is typical.

The Generic I/O Module connection might work more predictably than the tag data access method, because the connections and resources are pre-allocated and not subject to the availability of buffers, but that's generally a much smaller amount of data so it may not fulfill the application's needs.

Ken Roach said:

CIP capacity limits usually manifest themselves as refused connections, as in "it works when we have 15 panels connected, but the 16th panel does not connect". When a connection drops and then re-establishes, it suggests a timeout.

Click to expand...

I thought this too. I ran into this because I didn't realize the 1747-AENTR makes a separate CIP connection for each module in the rack and when I'd plug in a second Panelview, I wouldn't be able to go online. I figured maybe the fact that it's Automation Direct it might behave differently. Also, I know you can lower the number of CIP connections in a Panelview but A-B warns you the connections can become unstable if you do. I figure maybe the C-Mores are doing this automatically.