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Inverting the Direction of a joint in Tandem Axis has no effect
Inverting the Direction of a joint in Tandem Axis has no effect
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11 May 2021 20:44 - 11 May 2021 20:51 #208581
by MartyJ
Hello all,
I am setting up a XYYZ gantry machine. 5i25/single 7i76 setup driving Leadshine closed-loop stepper drivers.
I want to invert the direction of the tandem joint, in my case, that's stepgen 3, using:
setp hm2_5i25.0.stepgen.03.direction.invert_output true
- Because it's a closed-loop driver system, switching A+/A- wires will not work to invert the direction of the motor.
- The stepscale is a positive value for both joints in this tandem axis.
- There is no combination of stepscale sign or inverting stepgens 01 or 03 which result in stepgen 03 inverting its drection, even though I verify that the stepgen.03.direction.invert_output parameter is successfully registered as "true".
Any other ideas? Ini/HAL attached, thanks!
Last edit: 11 May 2021 20:51 by
MartyJ.
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11 May 2021 21:55 #208587
by tommylight
The direction can be inverted by simply putting a - in front of the SCALE in the ini file, or removing it if there is already there.
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11 May 2021 23:28 - 11 May 2021 23:30 #208599
by MartyJ
Thanks! So I tried that, that's what "POS" and "NEG" mean in the STEPSCALE fields in the chart in my first post.
For my primary joint on stepgen 01, adding a - in front of the stepscale value reverses the direction of the motor. For the secondary stepgen, it does not.
Last edit: 11 May 2021 23:30 by
MartyJ.
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11 May 2021 23:29 #208600
by PCW
Since stepgen 3 never changes direction, I would suspect a hardware problem
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11 May 2021 23:31 #208601
by MartyJ
Huh. I'll try hooking it up to stepgen 4 and see what happens, thanks for the idea.
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11 May 2021 23:45 #208603
by PCW
Might be drive wiring also
You can test the direction inversion with a voltmeter or just a
LED and halcmd
halcmd setp hm2_5i25.0.stepgen.03.direction.invert_output true
halcmd setp hm2_5i25.0.stepgen.03.direction.invert_output false
Should toggle the output polarities of the direction 3 outputs
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11 May 2021 23:46 #208604
by MartyJ
Bingo, thanks so much gents.
I'll buy a new 7i76, but for now moving to stepgen 4 has me up and running.
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12 May 2021 21:31 #208653
by andypugh
Bingo, thanks so much gents.
I'll buy a new 7i76, but for now moving to stepgen 4 has me up and running.
Could be wiring? Wire the wrong side of the cage clamp?
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13 May 2021 01:01 - 13 May 2021 01:01 #208681
by MartyJ
In the end (hopefully) it was EMF the whole time. I was using a non-shielded ribbon cable to connect the 5i25 to 7i76 inside my controller box, and it passed nearby my toroidal power supply. Now I'm using a different cable routing and shielded cable, hopefully sorted.
Last edit: 13 May 2021 01:01 by
MartyJ.
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Inverting the Direction of a joint in Tandem Axis has no effect
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