Bad Behavior Goes Away When One Node Removed

[RMP 10.3.8]

A couple months ago, I worked with Jacob on a machine that was behaving very strangely. It had 4-5 Yaskawa drives and 3 or so Beckhoff I/O cards. If everything was connected to the EtherCAT network, the network would fail to start. If I removed any node from the network, it would start and function correctly. Jacob did a cursory inspection and noted that we didn’t have anything obviously misconfigured. One of the I/O cards was unnecessary, and we needed to ship the machine, so I just removed the card and hoped it was a fluke.

I’ve got a different machine exhibiting (perhaps) analogous behavior. It’s got 5 identical axes (EverCNC Titanio) and some Beckhoff I/O cards (DI8, DI8, DO8). The network starts, but the inputs are not getting to my application. They look good in RapidSetup, but my application is basically getting stale values for them all. (We’re using recorders to get inputs so that lots of different threads/code points can get the “current” state of the input without calling into the RMP library.)

If I remove any one of the drives from the network, this problem doesn’t happen, and I get all the inputs correctly.

The addresses I’m giving the recorder APIs are coming from NetworkNode->DigitalInAddressGet(...). I haven’t made any changes to this code in over a year, and it seems to have worked fine on dozens of machines (with varying configurations) that we’ve set up in the past and all our current test machines.

Do you have any suggestions for ways to diagnose this problem?

Per our phone conversation, I think looking at Recorder registers in VM3 will give us the clues we need to see what’s going on. Keep us posted.

1 Like

When I look at the recorder configuration (in VM3), I can see that there are not as many configured items as should be there. Thanks for pointing out how to inspect this.


The problem I had was a miscalculation when there were exactly 31 items in the recorder (i.e. the max, since I include the sample counter as item #0).
Thanks for the help.