Ethercat, EL6751 and CANOpen

this is canopen for sew lteb vfd which should be workable for non rigid tapping purposes ... I running them 18k low cost spindle just for researching

Hello endian,
great, in the end I found somebody who is brave enough to work on the kollmorgen servos! Awesome!
In the appendix, you can find a tarball of my current version. As I said, the drive is somehow communicating with lcnc, but I do have terrible timing issues.

In a nutshell, what I did or tried to do:

set up the EL 6731 using twincat3

• PDOs for parameter channel and process data
• cycle time 1ms
• use of Ethercat MDP Mapping and upload the config to the EL6731, hence no init commands or startup sdos in ethercat.xml on lcnc side necessary (Not sure here)
• not sure about settings for Distributed Clocks (just left it default, at the moment)

lcnc comp

• use parameter channel to set operation mode <--- velocity
• byte swapping magic (not sure If I got that right)
• scaling the velocity and position feedback (not sure about the scaling numbers, docu is a mess, as you probably know

lcnc ini/hal

• try to use a simple PID loop: position command (from motion, setpoint) position-feedback (from servostar. Here I do have the issue -- due to comm problems this data is very laggy, hence the PID cannot do its job) PID output == velocity command to servostar

Here are my issues / todos

• I'm not sure if I correctly use the parameter channel of profibus (PKW) Due to lack of understanding of SDOs, I simply put the PKW as an PDO and initialize the drive on startup -- IMHO it would be better to do that via SDO or some other hard-coded init sequence I'm not aware of. Maybe the constantly send/rec of the parameter channel causes the timing issues.
• I need to parameterize the velocity profile for the position loop. Where to do that? Drive GUI?
• Homing: I think of simply use the built-in homing method of lcnc, the implementation in the hal comp seems to be a bigger time effort. Here a question, in case the homing switch is reached (digital I/O of another EL card) how to set the position feedback of the kollmorgen servo to zero.
• Enable the drive is working, disable is buggy -- need to correct this

Sorry for the lengthy message, but maybe you have some hints on one of the issues. I'll definitly take a look at the other thread and your provided info. Thanks again!

BR Franz

in the appendix my servostar profibus attempt.
Btw, here are details of my setup:
Servostar 603, Firmware 5.76, HW version 49.01
AKM31E Servomotor

• PDOs for parameter channel and process data - You have to set SDO via ethercat-conf.xml on startup else there will be a default values I thought
• cycle time 1ms - this is right, default is 4ms which should cause lagging
• use of Ethercat MDP Mapping and upload the config to the EL6731, hence no init commands or startup sdos in ethercat.xml on lcnc side necessary (Not sure here) - yes they are necessary
• not sure about settings for Distributed Clocks (just left it default, at the moment) - you active DC, it is for EL6731 necessary, GC for profibus are possible but they are not implemented in the kollmorgen card yet 

lcnc comp

• use parameter channel to set operation mode <--- velocity - from character of movement, it is necessary only velocity mode because positionning are over motion tasks in the servo internal.. 
• byte swapping magic (not sure If I got that right) - I will share my program with them... there it is probably right because it jump to enable and I had a position feedback directly
• scaling the velocity and position feedback (not sure about the scaling numbers, docu is a mess, as you probably know

Here are my issues / todos

• I'm not sure if I correctly use the parameter channel of profibus (PKW) Due to lack of understanding of SDOs, I simply put the PKW as an PDO and initialize the drive on startup -- IMHO it would be better to do that via SDO or some other hard-coded init sequence I'm not aware of. Maybe the constantly send/rec of the parameter channel causes the timing issues. - there it is little bit different, it had only one universal canal where datas are mirroring each other - you have to be carrefull and you have to get right answer from driver itself... 
• I need to parameterize the velocity profile for the position loop. Where to do that? Drive GUI? - position loop as in the CiA standard are not directly possible because of idea of communication shape itself 
• Homing: I think of simply use the built-in homing method of lcnc, the implementation in the hal comp seems to be a bigger time effort. Here a question, in case the homing switch is reached (digital I/O of another EL card) how to set the position feedback of the kollmorgen servo to zero. - it should be tested in the drive gui and then u should run it over op mode 1 with 14 and 15 bit of zsw off ... characteristic have to be done in the driveGUI soft itselft before... I did tutorial of driveGUI installation on the Debian distro before.. lets check them, you should have easier live after
• Enable the drive is working, disable is buggy -- need to correct this  - 

Hi endian, Thanks for your answers. I'll try to follow your advices. Another question: How do I setup the SDOs. Do you have some hints for me?
BR Franz

Yes I have had done it ... I will post them tomorrow ... Take an inspiration from them there will be a ET200B from siemens, keb f5 vfd and kollmorgen s343... But... I am out of shop today .. family stuff

Regards