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read EtherCAT status


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I'm using an EtherCAT Yaskawa amplifier. Because of some hardware issues, the encoder occasionally heats up and the amplifier has an alarm. At this point the control of the coordinate system goes awry, with the other axes seemingly continuing motion. I think this is because there's seemingly no error on the PMAC side.


I can read the error

debug1 = ecattypedsdo(0,2,1,$603F,0,0,4) debug1

P8208=2144 //0x860 = overheat


but I saw some document not to put this in a loop, presumably because it is slow. I could make a loop that only read it every 10ms. Is there any standard way to handle this?


And to stop can I just issue a Motor[3].InterlockStop?



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I think your best bet is to use the "auxiliary fault" function here. (I am a little surprised that this is not rolled into the standard amplifier fault bit, but auxiliary fault was meant for special cases like this.)


You ~10-msec sampling routine needs to put your sampling result into a fixed bit of an integer register (possibly Sys.Udata in the shared buffer). Then you point to this register with Motor[x].pAuxFault and specify the bit with Motor[x].AuxFaultBit. Also set AuxFaultLevel and AuxFaultLimit.


Now when the fault occurs, PMAC will automatically "kill" this motor, and stop all other motors in the coordinate system, either to a closed-loop zero-velocity state, or a disabled (killed) state, depending on the setting of Motor[x].FaultMode.

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JeffB. You set everything up the normal way (with system setup) so that Motor[x].pAmpFault is pointed to an EtherCAT register? That really sounds like it should be part of the normal amp fault function. Curt's suggestion to use the auxiliary amp fault bit should solve the problem.


Motor[3].InterlockStop is a status bit.

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Thanks Curt, Eric


It looks like EtherCAT is correctly configured:








So I wrote a plc routine to monitor.


from configuration.pmh

﹒﹒Motor[3].pAuxFault = Sys.Udata[0].a

﹒﹒Motor[3].AuxFaultBit = 0

﹒﹒Motor[3].AuxFaultLevel = 1

﹒﹒Motor[3].AuxFaultLimit = 1


// PLC Motor Monitor

//check for alarm on Yaskawa amplifier


#define ECAT_NETWORK 0

#define J3_AXIS_INDEX 2

#define SDO_READ 1 //Service Dictionary Object




OPEN PLC MotorMonitor

local time_sec = 0.0;

local alarm


//if motors from coordinate system 1 are moving

if (Coord[1].DesVelZero != TRUE)


﹒﹒if (time_sec < Sys.RunTime)


﹒﹒﹒﹒time_sec = Sys.RunTime + 0.010//10ms


﹒﹒﹒﹒if (alarm == YASKAWA_OVERHEAT_ALARM)

﹒﹒﹒﹒﹒﹒Sys.Udata[0] |= $1


﹒﹒﹒﹒﹒﹒Sys.Udata[0] &= ~$1





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Unfortunately, commands to read SDOs won't work in realtime processes, such as Motion Programs or realtime PLCs. Waiting for a response from the slave device would block execution of other realtime PLCs and/or the motion calculations. As such, whether in a motion program or a subprogram called from one, the ecattypedsdo command will not wait for a response.
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I figured the reason was something like that; unless I missed something, it sounds like it's time for a manual update.


So I assume the preferred method of calling ecattypedsdo from a motion program would be to call a non blocking plc routine and wait until plc routine was done by looking at when Plc[x].Active and/or Plc[x].Running equals false.

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Pretty much--I might leave the PLC active at all times and just pass a flag back and forth instead, but it's the same general idea. You could even make it more generic:


GLOBAL ReadWriteSDOFlag = 0

GLOBAL EcatMasterNum = 0

GLOBAL EcatSlaveNum = 0

GLOBAL EcatReadWriteFlag = 0

GLOBAL EcatIndex = 0

GLOBAL EcatSubIndex = 0

GLOBAL EcatValue = 0

GLOBAL EcatNumBytes = 0

GLOBAL EcatResult = 0




IF(ReadWriteSDOFlag == 1)


EcatResult = ecattypedsdo(EcatMasterNum,EcatSlaveNum,EcatReadWriteFlag,EcatIndex,EcatSubIndex,EcatValue,EcatNumBytes)

ReadSDOFlag = 0




Then just have your motion program set the parameters you want to read/write, set ReadWriteSDOFlag true, and wait for it to go false and read the result from EcatResult.

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