Hey, so...
I am looking to keep various EtherCAT slaves in sync and the default settings in PowerPMAC IDE for an Acontis CK3E appear to work for about 10-20 minutes.
Within this goldy locks zone of operation, I can time I/O slice input and outputs, watch system times from slave devices, and get a maximum offset or jitter of 0.8us; this is on par with the DC sync characteristics I get when utilizing the same hardware setup in TwinCAT.
After 10-20 minutes of operation of the CK3E master, the timing of my I/O slices immediately becomes indeterminate and I start seeing jitters as high as 65us. This appears to correspond with the task manager reported "EtherCAT Tasks" CPU percentage time (4khz rate * 27% utilization = 67.5us). To me, this alludes to a timing conflict between the EtherCAT servo tick and the DC Sync pulse; but I can't be certain since I don't know how to monitor either of these processes. A vast majority of the ECAT[].Slave[].DCxxxx variables have no context for Acontis, only for Etherlab stack so I don't even know what dial to turn or button to push to see whats going on under the hood of the Acontis master.
CK3E Firmware Version 2.5.4.0
PowerPMAC IDE 4.4.1.7
Slave Hardware:
Beckhoff EK1100 Bus coupler
Beckhoff EL1252 Input Module
Beckhoff EL2252 Output Module
Copley BEL-090-06
Troubleshooting steps that have not provided any gains:
1. clear config, start from scratch.
2. changing servo rate (4khz to 2khz)
3. changing ethercat rate (4khz to 2khz)
4. setting slave distributed clocks to different cycle rates with an appropriate offset
5. power cycling the slaves (not the master)
6. ecat reset
7. adjusting DC timing variables (plus,minus,kp,ki,refband)
8. change dc to master shift or bus shift.
Any help is greatly appreciated,
David
I am looking to keep various EtherCAT slaves in sync and the default settings in PowerPMAC IDE for an Acontis CK3E appear to work for about 10-20 minutes.
Within this goldy locks zone of operation, I can time I/O slice input and outputs, watch system times from slave devices, and get a maximum offset or jitter of 0.8us; this is on par with the DC sync characteristics I get when utilizing the same hardware setup in TwinCAT.
After 10-20 minutes of operation of the CK3E master, the timing of my I/O slices immediately becomes indeterminate and I start seeing jitters as high as 65us. This appears to correspond with the task manager reported "EtherCAT Tasks" CPU percentage time (4khz rate * 27% utilization = 67.5us). To me, this alludes to a timing conflict between the EtherCAT servo tick and the DC Sync pulse; but I can't be certain since I don't know how to monitor either of these processes. A vast majority of the ECAT[].Slave[].DCxxxx variables have no context for Acontis, only for Etherlab stack so I don't even know what dial to turn or button to push to see whats going on under the hood of the Acontis master.
CK3E Firmware Version 2.5.4.0
PowerPMAC IDE 4.4.1.7
Slave Hardware:
Beckhoff EK1100 Bus coupler
Beckhoff EL1252 Input Module
Beckhoff EL2252 Output Module
Copley BEL-090-06
Troubleshooting steps that have not provided any gains:
1. clear config, start from scratch.
2. changing servo rate (4khz to 2khz)
3. changing ethercat rate (4khz to 2khz)
4. setting slave distributed clocks to different cycle rates with an appropriate offset
5. power cycling the slaves (not the master)
6. ecat reset
7. adjusting DC timing variables (plus,minus,kp,ki,refband)
8. change dc to master shift or bus shift.
Any help is greatly appreciated,
David