problems with mach4 and pmdx 422 controller.

[davidlauten]

I get under run failures with jog steps less than 1.0. If i go to zero from 10 inches it will lock up at about half way with no error indication. I have Mach4 build 2057. and PMDX 422 drivers from 12 dec 2014. Brand new board.

[Bob at PMDX]

I get under run failures with jog steps less than 1.0. If i go to zero from 10 inches it will lock up at about half way with no error indication. I have Mach4 build 2057. and PMDX 422 drivers from 12 dec 2014. Brand new board.

I presume you mean Mach4 build 2157 (not 2057).

Just to make sure I understand: you have Mach4 set for "Jog Mode" = "Step", and are trying to use jog steps < 1.0 (i.e. 0.1000 or 0.0100, etc by clicking on the "Cycle Jog Inc" button).  You have the axis positioned at 10" and then try to jog back to zero.  This should take many clicks on the jog button (or keystrokes if you have the keyboard plugin running), correct?

Do you have a license file for Mach4?  Since didn't buy Mach4 through us, you need to contact whomever you bought it from to get a license.  Or if you haven't purchased a license yet, you can here:

                       http://pmdx.com/mach4hobby

And when you are trying to jog the machine with small jog increments, the machine "locks up" - can you be more specific (and I apologize for playing 20 questions with you here but it helps me know exactly what you are seeing):
- Does the machine stop moving (I presume so)?
- Does Mach4 respond to any mouse clicks or keyboard input?
- Is the "Enable/Disable" button flashing?  Green?  Red?
- Can you click on the "Enable/Disable" button in Mach4 and have it respond (i.e. change colors)?
- Can you exit Mach4 by clicking on the red "X" in the upper right corner, or do you have to kill it using Windows Task Manager?
- Do you see any message in the Mach4 status line (bottom left of the window, next to the "History" button)?
- If you select a jog step 1.000 or higher, you have no problems, is that correct?  If so, at what step value do you start to see the "lock up"?

I am seeing an issue here with jog steps set to 0.010 and I get a "PMDX-SmartBOB-USB INTERNAL ERROR: Motion queue underrun" message in the Mach4 status line and the "enable" button is flashing.  For my motor tuning setup, a jog step size of 0.100 works fine.  I am working on a fix for this issue, and I would like to see if what you are experiencing is the same issue.

Bob

[Bob at PMDX]

Sorry - as I was sending my previous reply I finally did see the phrase "underrun failures" in your original message.  So if you are indeed seeing the "PMDX-SmartBOB-USB INTERNAL ERROR - Motion buffer underrun" message, let me know.

Bob

[Bob at PMDX]

I've posted a new version (version 0.14.72) of the plug-in on our download page:

http://www.pmdx.com/PMDX-SmartBOB-USB-Plug-In

This version fixes the bug that produces buffer underrun errors when jogging in "step" mode with small step sizes.  You should see the firmware download dialog the first time you start Mach4 with this version - make sure to allow the plug-in to download the new firmware.

Bob.

[davidlauten]

New info on my systerm & the PMDX-422 & Mach4. I connected  the 422 ionto my Mach3 system buffrer board, which I had been using with UC300-5lpt motion controller. It seemed to work but with the problems I mentioned in my 1st post. After connecting the 422 directly into my system by-passing the Mach3 buffer bd most everything is working correctly. I saw there is  new firmware for the jog stepping underruns but haven't downloaded yet. I still have a problem with Z axis not returning to zero location after a request for go to zero. no errors just no response from the Z axis, yet I can jog the Z axis. Thanks for all the replies.

[Bob at PMDX]

After connecting the 422 directly into my system by-passing the Mach3 buffer bd most everything is working correctly. I saw there is  new firmware for the jog stepping underruns but haven't downloaded yet. I still have a problem with Z axis not returning to zero location after a request for go to zero. no errors just no response from the Z axis, yet I can jog the Z axis.

First, please download and install the new plug-in.

Now, help me understand your setup - when you have the PMDX-422 connected "directly to your system", what exactly is it connected to?  And how is it connected?  For example, from looking at your order, is the PMDX-422 connected to the PMDX-134 using the ribbon cable and then the PMDX-134 is plugged into the Gecko drivers?

And a few more questions to help clarify things:
- Do you have a licensed file for your Mach4 install?  If in doubt you can verify that the license is installed correctly by going to the "Help->About" menu in Mach4.
- You say that you can jog the Z axis.  Can you jog it in both directions?
- When you try to get the Z axis to return to zero, exactly how do you do that?  Do you click on the "Goto Zero" button?  Do you enter a command like "g0z0" or "g1z0" in the MDI window and click "Cycle Start"?  Is this part of a canned GCode file?
- When you try to get the Z axis to return to zero, does it move at all?  Or does it stay in place?
- Does the DRO for the Z axis change?
- Does Mach4 still respond to your input?  For example, *after* you try to return the Z axis to zero and you get "no response", can you jog or move any other axis in either direction? Can you move the Z axis in the positive direction (away from zero)?
- Presuming this is a milling machine, is Z axis motion "toward zero" moving the head up or down?
- What is your "jog rate"?  Click on the "Jogging" tab in the lower portion of the Mach4 screen and look at the slider and "Jog Rate" field at the bottom.  It should be a percentage value like 50%.
- If the "jog rate" is not at 100%, what happens if you set the jog rate to 100% and try to jog the Z axis up and down?

Bob

[davidlauten]

after further review I found that my Mach4 when run in simulation mode, doesn't return the z axis to zero after the x & y are at zero. I have always used either Mach 2 or Mach3 and they returned Z to zero after X & Y had reached zero. I guess that is just a change for Mach4? Everything else is working correctly.

[Bob at PMDX]

after further review I found that my Mach4 when run in simulation mode, doesn't return the z axis to zero after the x & y are at zero. I have always used either Mach 2 or Mach3 and they returned Z to zero after X & Y had reached zero. I guess that is just a change for Mach4? Everything else is working correctly.

Are you seeing this when clicking on the "Goto Zero" button?  Or while running GCode?

Bob

[davidlauten]

on the go to zero.

[Bob at PMDX]

on the go to zero.

Check your email.  I've sent you an updated screen set that should fix this.

Bob

[davidlauten]

It did fix it ok.

[Doddjn]

I had this problem and solved it by insuring that I tuned the jog step to the true movement of the plane. My screws are 40 threads per inch and my steppers are 400 steps per revolution or 16000 steps per inch. This moves the table by .0000625 per step. So I changed the Cycle Jog Inc on the 10000 to 5/10000 and that resolved the issue. Any other setting would cause the error that you reported to appear

John