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Full Version: Custom and faster implementation for the PMATCH command
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Hi,

We are using quite some of the older and slower 60MHz PMAC-PC boards where the product processing application has some lengthy background PLC routines and continuously data-gathering upload (list gather commands) through the host interface during the production process.

During its 25 seconds product processing cycle, the running motion program is using following mode about 150 times with RAPID moves in-between.
Due to the background PLC processing and gather upload commands, the PMATCH commands after the following mode can take up to 25 milliseconds, and to speed-up the production process I want to use a custom and more efficient alternative to PMATCH.

The motion program has just a single X-axis with 1 motor, and writing directly into the CS1 X-axis target position register (m165_Cs1XaxisTargetPos->L:$081F) to manually sync it with the commanded+master motor position seems to do the same as the PMATCH command (and much faster).
I did a test with a motor and our production process in simulation mode (not on a real machine yet), and everything seems working fine with an almost 10% faster cycle time.

Does anyone have experience using such a custom and faster alternative for calling PMATCH from a motion program?
Or is the PMATCH command doing more than just syncing the motor position(s) to the axis position(s)?

Thanks and regards,

Jan
I don't know of another way. Generally, PMATCH should not take longer than about 5 milliseconds. It does not perform additional tasks that would slow it down.

Is there a Dwell 0 command before and after the PMATCH commands (longer Dwells could be reduced to DWE 0).

Also, note that PMATCH is not needed if the position following is in offset (not normal) mode.

Anyhow, your alternate method should be OK.