CompactLogix, maximum number of 3:rd party HMI connections?

[Supporter 1]

Hi, We are trying to connect more than 15 Beijer operator panels to the same CompactLogix CPU (via Ethernet). 15 panels are working OK but when trying to add the 16:th panel to the network it will Always get a Comm Error (the other 15 are still working OK). I'm assuming that this has nothing to do with the Beijer driver since 15 panels can connect and communicate properly, the limitation seems to be on the CPU-side. According to documentation I found the CPU should support 256 CIP Connections (and 120 TCP Connections). I've not been able to find any references to limitations similar to our situation/application. Do you have any ideas or tricks that we could test? I appreciate any help or advices that you can provide.

[Mark- 17]

Hello, http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1769-um011_-en-p.pdf Page 50 The 1769-L32E and 1769-L35E controllers support 100 connections. However, the built-in EtherNet/IP port supports only 32 CIP connections over an EtherNet/IP network. With these controllers, the number of end-node connections they effectively support depends on a connection’s RPI. Requested Packet Interval - Max EtherNet/IP Port Communication Connections 2 ms - 2 4 ms - 5 8 ms - 10 16 ms - 18 32 ms+ - 25+

[Ken Roach 194]

Mark is on the right path. Exactly which CPU are you using ?

[BobLfoot 302]

Not that it's related, but it is similiar. I once did a job with a ControlLogix CPU and 128 GPPro HMI. Yes 128 HMI. For optimum performance we wound up using 8 ethernet cards in the rack with the single cpu. Turns out there are some connection limits both at the CPU and at the adapter which can give you headaches for multiple HMI configs. OF course that was 8 years ago the tech has improved since then.

[Ken Roach 194]

My guess is that the Beijer panels are using 2 CIP connections each, and that the controller is a 1769-L32E or 1769-L35E. It's also possible that there are other CIP connections in use to the controller, including the RSLogix 5000 instance, or maybe some remote I/O over EtherNet/IP. Supporter didn't say how many panels he has to connect, just that it is 'more than 15'. If he can describe the scope of the machine control network, he can predict whether the architecture is even possible with the controller he is using. The embedded Web page of the CompactLogix will show both scheduled and unscheduled connections, so that's an easy place to start. Disconnect all the Beijer panels, then connect one at a time and see what shows up on the CIP connection diagnostic display on the web page. The RSLogix 5000 Task Monitor utility may also be useful in this case, to show the number of connections being made over the Ethernet daughtercard. It's a free tool that is installed with RSLogix 5000 and generally launched from the Tools menu in RSLogix 5000.