CompactLogix 1769 l35e ethernet hanging up?

[Ken Roach]

kf5pv: You should be able to do some diagnostics using the embedded web page.

If you are having collisions or the media error counters are increasing on the Ethernet port, solve the media problems first.

Another issue I've run into with older firmware (prior to v16) is that MSG instructions that are self-retriggering or are fired by a timer without regard to whether they've completed or not tend to clog the backplane buffers between the Ethernet daughtercard and the CPU.

The CompactLogix 1769-L32E and -L35E both only support 32 CIP connections, so it wouldn't take much to cause the controller to run out of resources if you're regularly running at 27 connections.

Can you optimize any of your connections, like Produced/Consumed Tags or Rack Optimized I/O ?

 

[NevisGroup]

I ran into some network switches that seam to have problems with the communications. Everything works fine for a while then it all starts to fall apart. I had a nice managed switch that turned out to be too smart for it own good. There were two issues. It would decide (for no good reason) to try to negotiate link speeds at random.
The bigger problem was that the switches internal tables were getting corrupted. Power cycling the switch fixed things for a while. I put in a cheap switch that was in the bottom of may laptop bag and all was well.
Had something to do with the PLC (Rockwell) communications. The managed switch is off in a different corner of the building and working fine with a room full of CAD stations plugged into it.


Of course YMMV. Just something I ran into.

 

[TheWaterboy]

i have seen switches that don't handle auto negotiate properly. try setting both ends to a fixed setting.

 

[kf5pv]

I think I got the 27 connections from the task monitor.
That was some info I was given by someone else.

 

[The Plc Kid]

I think I got the 27 connections from the task monitor.
That was some info I was given by someone else.

I recommend you download and use the ethernet Ip connections tool from the Rockwell website and use that to count your connections yourself.

You may be suprised at what you get.