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- Replacing Advanced Motion Controls "brush type 12A8 with "Axcent" amplifier
Replacing Advanced Motion Controls "brush type 12A8 with "Axcent" amplifier
- OT-CNC
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I have plugged power supply in to the wall and released e-stop, the software was in process of boot up and as soon as releasing e-stop x axis started jerking and red LED on AMC driver was blinking, so I quickly reset e-stop. Open to ideas. Many thanks!
I would start with a new clean configuration and test your encoder first without the motor connected to the table. You need to check the feedback loop is correct for both linuxcnc and the drive. Don't power up the motor. Spin shaft manually to see if it counts in the correct direction reflecting travel of tool. This is to prevent a runaway if the pid loop is reversed. Check to see if count increases when the tool travels in a positive direction in linuxcnc. Once the motor is powered, the pid loop may be incorrect in the drive which makes it easier to trouble shoot if you know that linuxcnc is correct then you can reverse it on the drive end.
See the configuration switch section of your drive pdf. SW1-6 , on/off to reverse.
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- new2linux
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many thanks
Edit:
After using the Pncconf Wizard, I have saved a new version of the .ini & .hal files. Being that this is a 2 axis machine w/o spindle speed control and I don't want to use the 1 and 2 of encoder & drive inputs on the 7i77 card, is it better to start with a 2 axis machine (when using pncconf wizard) and edit (with text editor) or try to edit existing files with the wizard? There naturally several options in the wizard to pick from, is there a preferred way to approach or to think about it?
many thanks to all for the help, I am very grateful!
Edit01: I think set up for 5 axis but only use 3 (x,y &z). Edit after the wizard has worked so the x & y axis are with encoders 02 & 03 (at location TB3 & TB4) and just over look the areas that will not be used.
Edit02: I have went back to original .ini & .hal files, with wires under screw as per prior suggest, using the SW1-6 (this is AMC driver) to "off or on", did not allow x axis motor to stay w/o motion. There is no DRO with x or y axis. I was not shore how to proceed with Pncconf Wizard if I was not using the 00 and 01 address. I will be working on DRO.
Many thanks
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- new2linux
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For velocity mode you need SW1-1 OFF, SW1-3 OFF.
The other switches are not mode dependent.
SW1-2 OFF for brushed motors
SW1-4 OFF for offset adjustment
SW1-5 sets the inhibit logic. If you don’t have anything connected to pin 9, leave it ON
SW1-6 sets the velocity feedback polarity, so it depends on how the encoder is installed and wired. It’s ON by default, switch it if the motor runs away. (this is set to off now, but motors w/o belt turn, POT 1 full CCW will not slow the RPM,)
Include the POT details included in the attachment:
POT1: Loop Gain Adjustment; In Velocity, Voltage, or Duty Cycle Mode, this potentiometer adjusts the gain in the velocity forward position of the closed loop. Turning this potentiometer clockwise increases the gain. Start from the full
counter-clockwise position, turn the potentiometer clockwise until the motor shaft oscillates, then
back off one turn.
POT2:
POT3:Reference Gain; This potentiometer may be left in the fully clockwise position if a
controller is used to close the velocity or position loops.
POT4:
I am not shore I am up to the task of using the Pncconf Wizard in addition to editor, as to allow not using the encoder 0 & encoder 1 (located TB3) and DRV 0 & DRV 1 (located TB5) for fear that the 7i77 may be smoked. If this is so then I need to order a new 7i77 card and get on with it.
many thanks
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- new2linux
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This last "how to" by John Kasunich, describes how to turn motor w/o power to them by hand to test the encoders one at a time. When I click on linuxcnc to start, if the power to the motors is not "on" the screen will show (looks to be raw code error data) about 1/2 way down there is a debug about error so and so. If I power this up with "power to motors" the normal screen for linuxcnc (the logo screen) will load and I have access to the HAL Scope and the other HAL related meters. So curentely, the motors always turn (I have SW1-6 to help this but seems to do very little) and no motion on the DRO. The motors are not at such speed or torque that if you push on the end of shaft it will stop, but will feel motor jerking/serging when stopped. I have read in John Kasunich's tuning about and need to get to this part:
"Verify DAC outputs
Connect a HAL signal to the DAC outputs, set the DAC scaling set to 1.0. Then with motor/amp power off, set the HAL signal to 1.0 volts and verify (with a meter) that the output is correct. Repeat with -1.0 volts. Then verify with larger values, depending on the range of the DAC, for example 5.0 volts, and -5.0 volts."
All help is warmly welcomed, I am just at the point where I am not shore of the area that needs to be addressed 1st. The only thought I have is that the leads that enable driver for Velocity control, are affecting the other settings, and maybe disconnect until after some of the other setting are set. Or the 7i77 card needs to be replaced.
Many thanks, all help warmly welcomed.
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- Todd Zuercher
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The 2nd thing you must have working is the encoder feed back. And here I am very confused by what you say you have and the photos of what you did have. Your initial photos and your drawing shows that you have(had) 6 wires connected to the 7i77 encoder input orange, red, grey, green, violet, and black. But then you reference a US Digital pigtail CA-LC5-W4-NC that only has 4 wires. Did you change encoders for some reason? I'm just not sure what you actually have going on.
For the 4 wire encoder you would move the jumpers on the 7i77 for encoder0 to thier single ended setting. Jumper W19 and W21 should be set to the left side (default was to the right). But if your encoder is in fact a differential one with 6 wires you should leave the jumpers in their default positions.
Does the encoder feedback work? (When you turn the encoder does the DRO change?) Does it work if the leads are connected to pins 6 and 7 of the drive? If not does it work when they are disconnected? You might also need to connect a wire from pin #11 on the drive to TB3#1 on the 7i77.
If you were trying to start Linuxcnc with the drive powered off and Linuxcnc failed to start, the most likely reason is that something you did to prevent the drives from powering probably also removed one of the power sources from the 7i77 card. But I can't say for sure without seeing the debug message or knowing more about exactly what you did.
It is ok for the drive to be powered when Linuxcnc is not in control as long as they are not enabled. (back to that pin#9 connection on the drive) If they are not enabled they will not be powering the motor.
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- AdvancedMotionControls
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Forgive me if I'm asking about something you may have already configured, but my first concern would be to make sure the servo drive is actually enabling. The 12A8 is for brushed motors, while the AxCent may be for brushed or brushless depending on what model you have. My assumption from the title is you've replaced the drive but not the motor, so your system currently consists of a brushed motor with possibly a brushless servo drive.
All of our brushless drives can drive brushed motors but there's a little bit of configuration to get them to enable.
Just chiming in to make sure you've eliminated any easy fixes on the servo drive side, and I'd be happy to help with any drive problems.
Edit: I didn't realize this topic was 7 pages long! My apologies if I'm jumping in well after the fact.
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- OT-CNC
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Welcome to linuxcnc and thanks for offering to help!
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- Todd Zuercher
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- new2linux
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Encode does not move DRO. I will be working pin 9 & 11 issues. many thanks!!
AdvancedMotionControls, Many thanks, for your thoughts. The project is 2 axis mill and DC brushed motor application. Please advise.
Many thanks
Edit:Attached is a pic of the debug info when 1st start up w/o power to motor, with the pin 9 & 11 connected to TB5 (positions 1 & 2). This also has 6 & 7 connected to TB5, as in earlier post. When I power up motors & restart linuxcnc, I get logo screen, the motors are in motion. As per suggestion SW1-5 is off (all SW1-1 to-6 is off). DRO does not move.
As per Todd's suggestion: . If you have accidentally already ruined the enable output for that drive on the 7i77 card, you can use one of the other unused enable outputs (they are all switched together anyway) or set up a relay and control it with one of the regular field outputs. This is TB2? Pick a different location use 1 through 4, like 2?
many thanks!
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- new2linux
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Many thanks, all help warmly welcomed!
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- Hardware & Machines
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- Replacing Advanced Motion Controls "brush type 12A8 with "Axcent" amplifier