Temporarily Disable Signal to Servo Amp

hunterlong
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11 Jan 2023 17:00 - 11 Jan 2023 17:04 #261591 by hunterlong

Replied by hunterlong on topic Temporarily Disable Signal to Servo Amp

Currently I have a custom.hal file that contains

# Load Classicladder
loadrt classicladder_rt
addf classicladder.0.refresh servo-thread
loadusr classicladder --nogui ladder.clp

# Tool change button
net tool-release-btn <= hm2_5i25.0.7i77.0.0.input-05
net tool-release-btn => classicladder.0.in-00
net tool-release-sig-drop classicladder.0.out-00 => hm2_5i25.0.7i77.0.0.output-00
net tool-release-sig-lock classicladder.0.out-01 => hm2_5i25.0.7i77.0.0.output-01
net tool-release-sig-push classicladder.0.out-02 => hm2_5i25.0.7i77.0.0.output-02

Can I just add to this custom.hal file?

loadrt and2
addf and2.0 servo-thread
net z-enable-joint and2.0.in0 <= joint.2.amp-enable-out
net z-enable-ladder and2.0.in1 <= classicladder.0.out-03
net z-enable <= and2.0.out0
net z-enable => pid.z.enable

I doubt that is right. I also attached my custom.hal, my_LinuxCNC_machine.hal, and my_LinuxCNC_machine.ini.

Thanks!
-Hunter

Last edit: 11 Jan 2023 17:04 by hunterlong.

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hunterlong
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11 Jan 2023 17:14 #261594 by hunterlong

Replied by hunterlong on topic Temporarily Disable Signal to Servo Amp

I just found this really helpful hal tutorial:http://linuxcnc.org/docs/2.5/html/hal/basic_hal.html

In my my_LinuxCNC_machine.hal I already have this section

#*******************
#  AXIS Z JOINT 2
#*******************

setp   pid.z.Pgain     [JOINT_2]P
setp   pid.z.Igain     [JOINT_2]I
setp   pid.z.Dgain     [JOINT_2]D
setp   pid.z.bias      [JOINT_2]BIAS
setp   pid.z.FF0       [JOINT_2]FF0
setp   pid.z.FF1       [JOINT_2]FF1
setp   pid.z.FF2       [JOINT_2]FF2
setp   pid.z.deadband  [JOINT_2]DEADBAND
setp   pid.z.maxoutput [JOINT_2]MAX_OUTPUT
setp   pid.z.error-previous-target true

net z-index-enable  <=> pid.z.index-enable
net z-enable        =>  pid.z.enable
net z-pos-cmd       =>  pid.z.command
net z-pos-fb        =>  pid.z.feedback
net z-output        <=  pid.z.output

# ---PWM Generator signals/setup---

setp   hm2_5i25.0.7i77.0.1.analogout2-scalemax  [JOINT_2]OUTPUT_SCALE
setp   hm2_5i25.0.7i77.0.1.analogout2-minlim    [JOINT_2]OUTPUT_MIN_LIMIT
setp   hm2_5i25.0.7i77.0.1.analogout2-maxlim    [JOINT_2]OUTPUT_MAX_LIMIT

net z-output     => hm2_5i25.0.7i77.0.1.analogout2
net z-pos-cmd    <= joint.2.motor-pos-cmd
net z-enable     <= joint.2.amp-enable-out

So I will need to unlink the joint.2.amp-enable-out and the pid.z.enable pin from the z-enable net before I connect my and2 gate.

so

loadrt and2
addf and2.0 servo-thread
unlinkp joint.2.amp-enable-out
unlinkp pid.z.enable
net z-enable-joint and2.0.in0 <= joint.2.amp-enable-out
net z-enable-ladder and2.0.in1 <= classicladder.0.out-03
net z-enable <= and2.0.out0
net z-enable => pid.z.enable

-Hunter

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hunterlong
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11 Jan 2023 17:32 - 11 Jan 2023 17:46 #261596 by hunterlong

Replied by hunterlong on topic Temporarily Disable Signal to Servo Amp

That worked! other than a few typos like and2.0.out0 is actually and2.0.out.

However, now as soon as I disable the PID with the pid.z.enable pin I get a following error in about 3 seconds.

Haven't tried while the z-axis was locked though. Maybe I won't get a following error.

EDIT: I can actually see the z-axis slowly drift down when I disable it, so no wonder I am getting a following error.
-Hunter

Last edit: 11 Jan 2023 17:46 by hunterlong.

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hunterlong
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11 Jan 2023 20:14 - 11 Jan 2023 20:22 #261616 by hunterlong

Replied by hunterlong on topic Temporarily Disable Signal to Servo Amp

It now works great! Thanks for all the help.

See the images and videos in this link (I added descriptions to each photo) for before/after: photos.app.goo.gl/A1DKWGkwW2Jyicae8

I can still get a following error if the z-axis is too high and travels down a bit before it hits the lock plate. Might try to fix this later, but as long as I get the z-axis height exactly right it works great. Tested like 10 times and no stuck lock plate, no servo driver faults!

-Hunter

Last edit: 11 Jan 2023 20:22 by hunterlong.

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tommylight
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11 Jan 2023 21:00 #261619 by tommylight

Replied by tommylight on topic Temporarily Disable Signal to Servo Amp

You cam set the min_ferror to a bit higher value in the ini file to prevent joint error.

The following user(s) said Thank You: hunterlong

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Todd Zuercher
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12 Jan 2023 21:20 #261741 by Todd Zuercher

Replied by Todd Zuercher on topic Temporarily Disable Signal to Servo Amp

hunterlong wrote:
Yeah, you are exactly right. Right now I don't have any sensor to indicate that the lock plate is in position, I just fire the air solenoid and assume it is. There is a switch I could wire up that is activated when the plate locks.

Here is a video of the lockbar working, and me accidentally dropping my edge finder because I was videoing and not paying attention

photos.app.goo.gl/AH9BLkDeBQpQepMd8

-Hunter

Perhaps you are trying to make this entirely too complicated. You say there is/was a switch that was triggered when the lockplate is enguaged. I wouldn't be at all surprised if the original control simply ran the servo amp's enable signal through that switch. So that when the locking plate was engaged the amp was automatically disabled. You could either do the same (and leave Linuxcnc unaware) or bring that signal into hal to disable the PID with a piece of hal logic.

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hunterlong
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12 Jan 2023 21:25 #261742 by hunterlong

Replied by hunterlong on topic Temporarily Disable Signal to Servo Amp

You know that is a really good idea Todd. Why didn't I think of that!

However, it is working now pretty well so I will keep that in mind in case I start having trouble again!

-Hunter

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Temporarily Disable Signal to Servo Amp

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