Localizing ECAT link outages

[jhenning]

We have a CK3E (FW 2.7.0.0)  with 31 EtherCAT slaves attached in a tree topology.  In case a station is lost due to cable problems or power loss we would like to identify where in the tree the problem occurs.  Our code is all in BGCPLCs, so a solution using C language constructs is desirable.

I have code that works:

    for (j=0; j<31; j++) {
        pshm->P[10] = j;
        Command ("L0 = P10");
        Command ("P11 = ECAT[0].Slave[L0].Online");
        if (! pshm->P[11]) { fault handling }

   }

Unfortunately it is very compute intensive, ~600us to complete the loop.  Given all the information gathering in Acontis, is there a PMAC variable or command that would immediately recognize and localize a station loss?

We could probably approach this in a more hardware-oriented way: since all stations have a digital input terminal, one line could be made always active, so if it reads 0 a station outage would be indicated, but this would be a fallback solution.

Thanks!

John

 

[steve.milici]

You may be able to identify a “gross” EtherCAT device “issue” in a PLC looking at one or more of the following elements and then run your BGCPLC to identify which slave is the offender:

Motor[x].AmpFault

ECAT[i].Error

ECAT[i].LineCrossed

ECAT[i].NotAllDevsOperational

ECAT[i].RTDomainOutputState

ECAT[i].Status[i] ;i=0-3

 

[jhenning]

Yes, using pshm->ECAT[0].NotAllDevsOperational to detect slave loss does make this PLC much more efficient (25% decrease in BG CPU usage) under normal conditions.

    if (pshm->ECAT[0].NotAllDevsOperational) {
        for (j=0; j<31; j++) {
            pshm->P[10] = j;
            Command ("L0 = P10");
            Command ("P11 = ECAT[0].Slave[L0].Online");
            if (! pshm->P[11]) { fault handling }

       }

   }

Thank you.