Sync Motion - how to follow an external encoder?

[bschmidt]

Hello,

What is the current and future plan for following an external encoder, aka Real Master? I know there will be encoder modules with ctrlX IO coming soon. What about a secondary encoder on ctrlX DRIVE? I assume we add S-0-0053 to the AT in ctrlX IO Engineering. Ideally there would be a special Axis Profile for encoder axis which only requires S-0-0053 to be mapped. The only thing I know to do is use an EtherCAT task in the PLC to feed this position (as %IDXX) into a virtual axis using MB_CyclicSetPoint. But there is no built-in deadtime compensastion or filtering in this case.

Best regards,

Brian

[Jochen_Mueller]

Hello Brian

following development planning

• ctrlX CORE version 2.4 (RM 23.11): support of Encoder axis with Indradrive
• with one of the next versions: support of Encoder axis with ctrlX DRIVE
• as soon we get the ctrlX IO encoder modules support of these at the Encoder axis too.

the request at the development was to realize the function "encoder axis" with the feature you are asking (deadtime compensation, filter, ...).

We (STS) plan to test this function latest begin of next year. Than we can say more.

Regards

Jochen

[bschmidt]

Hello,

With 2.04.3 I am testing Encoder Axis with IndraDrive. With the settings below I can see that my axis "Drive2_Encoder" is correctly reading the Measuring Encoder position P-0-0052 and converting to degrees.

However, when I try to synchronize a slave to it with MB_GearInPos I get this error:

The other problem I see is that I can't point a Drive Profile and Encoder Profile to the same drive. But in most cases this is what the customer will do. They will run the drive like any other drive but also bring in an external encoder to follow an upstream machine.

Best regards,

Brian

[bschmidt · Accepted solution]

My colleague pointed out my problem here. I had SyncSource at the default setting of SYNC_SETPOINT. It needs to be SYNC_ACTUAL or SYNC_ACTUAL_EXTRAPOLATED for an Encoder Axis, since the interpolated (commanded) position doesn't exist . Now it is working.