Trying to set up position control mode

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26 Feb 2026 15:45 #343538 by jblanscett
Trying to set up position control mode was created by jblanscett
Hi all,

We are working on a retrofit of an older Fryer lathe. We are using a Mesa 7i95 board and are trying to connect our SGDH-10AE Yaskawa drivers to the board in position control mode. We have managed to make the axes move in what seems like position control, but when changing the jog speed in AXIS, it also changes where the motion stops. I believe that I have made a mistake, or many, in trying to set up our HAL code. We generated the HAL code from Pnfconf and then made adjustments to try to change the Stepgen to position control mode. I was hoping that we could get some help in looking at our Hal and Ini files to see where we may have gone wrong. Or if someone has successfully implemented it, we could look at their files to see if we can figure it out. 

Thanks!

Jblanscett
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26 Feb 2026 16:27 #343543 by tommylight
Replied by tommylight on topic Trying to set up position control mode
I suspect interference, so pictures of the wiring from Mesa to drives might help.
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Why are there two posts with the same hardware and same issues by two members?
Are you the same team?
If yes, continue here.
Thank you.

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26 Feb 2026 17:22 #343548 by jblanscett
Replied by jblanscett on topic Trying to set up position control mode
Yes, we are the same team. I have attached photos. We have also looked at the signals from an oscilloscope and are getting nice clear step waves.

Thanks for the quick reply!
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26 Feb 2026 18:20 #343553 by tommylight
Replied by tommylight on topic Trying to set up position control mode

We have also looked at the signals from an oscilloscope and are getting nice clear step waves.

Check at the drive side.

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26 Feb 2026 19:23 #343558 by jblanscett
Replied by jblanscett on topic Trying to set up position control mode
I checked on the drive side and it looks clean as well.

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26 Feb 2026 19:48 #343560 by PCW
Replied by PCW on topic Trying to set up position control mode
The wiring does not look right to me, Don't those drives have differential inputs?

If they are differential, the 7I95 Step/Dir connections are wrong.

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27 Feb 2026 12:09 - 27 Feb 2026 12:13 #343596 by jblanscett
Replied by jblanscett on topic Trying to set up position control mode
Hi PCW,

I hope this is what you are talking about. We have our pn200 setting set at 5. Let me know if there is anything else I'm missing. Thank you for your time.

 
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Last edit: 27 Feb 2026 12:13 by jblanscett. Reason: Picture showed up as text

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27 Feb 2026 15:40 - 27 Feb 2026 15:47 #343605 by PCW
Replied by PCW on topic Trying to set up position control mode
Do you have the step/dir pinout information for the drive?

It does look like it may be single ended from the pictures of the
step/dir modes.

Also in your .ini file, you have the PID P term set to 0.
This should be 1000 (for a 1 ms servo thread period)
A 0 P term will cause position drift
Last edit: 27 Feb 2026 15:47 by PCW.

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27 Feb 2026 17:27 #343616 by jblanscett
Replied by jblanscett on topic Trying to set up position control mode
Here is the connector layout. We have the P value set to 0 because we aren't able to get the axis to move when it is set at 1000. I thought we would try to get the motion working better before worrying about it. If we need to figure that out first, I can work on that first. 

Thanks,

-jblanscett
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27 Feb 2026 20:07 #343621 by PCW
Replied by PCW on topic Trying to set up position control mode
1. A 0 P term will not work as it will drift it must be 1/servo_period
(1000 for a 1 ms servo thread period)

2. It looks like the step/dir inputs are differential so:

Drive        7I95
7   PULS    Step+
8  /PULS    Step-
11 SIGN     Dir
12 /SIGN    Dir-
 

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