News:

  • August 07, 2026, 07:46:59 PM

Login with username, password and session length

« previous next »
Pages: [1]

Author Topic: Runaway Pulse Output Axis?  (Read 15984 times)

scottsutton

  • Full Member
  • ***
  • Posts: 46
Runaway Pulse Output Axis?
« on: December 10, 2020, 03:23:52 PM »
I have a simple servo motion control program to move a servo 360 degrees. Also, the system has a home sensor to find the start point for rotation. I am using the pulse output to count the position and I am not using encoder feedback to verify position (if the servo looses position I get a discrete input indicating such).

However, I needed to change the homing routine so that it could be offset from the home sensor by around 100 counts instead of the current method to stop on the leading edge of the sensor signal. I used the built-in option to do this contained within the home function. But, now immediately after homing completes and it sets the success bit the pulse output goes to full speed as defined within the axis configuration. The servo will spin at full speed until I switch the mode toggle on the PLC to stop. There is no other active move within the code that would cause this. I changed the homing routine back to stop on the leading edge of the home sensor and the issue does not occur. So, currently that is that way that it is running, however I do need to offset from the home sensor for optimum utilization.

Any thoughts?

Scott Sutton
Logged

BobO

  • Host Moderator
  • Hero Member
  • *****
  • Posts: 6170
  • Yes Pinky, Do-more will control the world!
Re: Runaway Pulse Output Axis?
« Reply #1 on: December 10, 2020, 03:56:26 PM »
Quote from: scottsutton on December 10, 2020, 03:23:52 PM
I have a simple servo motion control program to move a servo 360 degrees. Also, the system has a home sensor to find the start point for rotation. I am using the pulse output to count the position and I am not using encoder feedback to verify position (if the servo looses position I get a discrete input indicating such).

However, I needed to change the homing routine so that it could be offset from the home sensor by around 100 counts instead of the current method to stop on the leading edge of the sensor signal. I used the built-in option to do this contained within the home function. But, now immediately after homing completes and it sets the success bit the pulse output goes to full speed as defined within the axis configuration. The servo will spin at full speed until I switch the mode toggle on the PLC to stop. There is no other active move within the code that would cause this. I changed the homing routine back to stop on the leading edge of the home sensor and the issue does not occur. So, currently that is that way that it is running, however I do need to offset from the home sensor for optimum utilization.

Any thoughts?

Scott Sutton

That should work as described. Checking...
Logged
"It has recently come to our attention that users spend 95% of their time using 5% of the available features. That might be relevant." -BobO

scottsutton

  • Full Member
  • ***
  • Posts: 46
Re: Runaway Pulse Output Axis?
« Reply #2 on: December 10, 2020, 04:00:57 PM »
Just for more information. I have another Do-More application that does home with an offset and it works as expected (also an open loop application). This installation was in early 2019 so it was with an earlier version of firmware/software.

Scott
Logged

BobO

  • Host Moderator
  • Hero Member
  • *****
  • Posts: 6170
  • Yes Pinky, Do-more will control the world!
Re: Runaway Pulse Output Axis?
« Reply #3 on: December 10, 2020, 04:01:42 PM »
Quote from: scottsutton on December 10, 2020, 04:00:57 PM
Just for more information. I have another Do-More application that does home with an offset and it works as expected (also an open loop application). This installation was in early 2019 so it was with an earlier version of firmware/software.

Scott

Is this HSIO module or onboard?
Logged
"It has recently come to our attention that users spend 95% of their time using 5% of the available features. That might be relevant." -BobO

scottsutton

  • Full Member
  • ***
  • Posts: 46
Re: Runaway Pulse Output Axis?
« Reply #4 on: December 10, 2020, 04:17:18 PM »
The current installation with the issue is a BX-DM1E-18ED23. I am using the onboard high speed outputs. The 2019 installation was with a 36 point BRX also using the onboard high speed outputs.

Scott
Logged

scottsutton

  • Full Member
  • ***
  • Posts: 46
Re: Runaway Pulse Output Axis?
« Reply #5 on: December 11, 2020, 06:19:39 AM »
This morning I am back onsite with the machine. I updated to the latest version of Do-More Designer (2.8.1) and updated the PLC boot loader and OS to the newest versions. No change in the issue, same runaway behavior. 

For the mean time I am just doing a one-shot discrete move after the homing success bit gets set to move away from the homing sensor, this works as expected but I would still like to know if I am doing something wrong with the built-in offset in the homing routine or if there is possibly a bug.

Thanks,
Scott Sutton
Logged

BobO

  • Host Moderator
  • Hero Member
  • *****
  • Posts: 6170
  • Yes Pinky, Do-more will control the world!
Re: Runaway Pulse Output Axis?
« Reply #6 on: December 11, 2020, 11:54:10 AM »
Quote from: scottsutton on December 11, 2020, 06:19:39 AM
This morning I am back onsite with the machine. I updated to the latest version of Do-More Designer (2.8.1) and updated the PLC boot loader and OS to the newest versions. No change in the issue, same runaway behavior. 

For the mean time I am just doing a one-shot discrete move after the homing success bit gets set to move away from the homing sensor, this works as expected but I would still like to know if I am doing something wrong with the built-in offset in the homing routine or if there is possibly a bug.

Thanks,
Scott Sutton

We are unable to dupe the problem. Are you using rotary mode?
Logged
"It has recently come to our attention that users spend 95% of their time using 5% of the available features. That might be relevant." -BobO

BobO

  • Host Moderator
  • Hero Member
  • *****
  • Posts: 6170
  • Yes Pinky, Do-more will control the world!
Re: Runaway Pulse Output Axis?
« Reply #7 on: December 11, 2020, 12:59:00 PM »
Actually it does appear that there is an issue with home search when in rotary mode. Investigating.
Logged
"It has recently come to our attention that users spend 95% of their time using 5% of the available features. That might be relevant." -BobO

BobO

  • Host Moderator
  • Hero Member
  • *****
  • Posts: 6170
  • Yes Pinky, Do-more will control the world!
Re: Runaway Pulse Output Axis?
« Reply #8 on: December 11, 2020, 01:16:49 PM »
It's a bug. The homing script is using a command that is illegal in rotary mode. I'm guessing it was introduced when we added AXSCRIPT. I think some of the commands got tweaked, and the rotary stuff was split out from linear mode.

AXHOME is actually just a macro of sorts, that generates a script, and then executes it. I was able to use AXSCRIPT to duplicate the behavior, substituting the correct positioning command for the broken one. I attached the script. You can import it from AXSCRIPT.
Logged
"It has recently come to our attention that users spend 95% of their time using 5% of the available features. That might be relevant." -BobO

scottsutton

  • Full Member
  • ***
  • Posts: 46
Re: Runaway Pulse Output Axis?
« Reply #9 on: December 11, 2020, 01:38:15 PM »
Yes, I am in rotary mode. Glad you were able to see the issue!

Thanks for the attention, this is one of the many reasons I will spec Do-More for any project that I have total control over.

Scott Sutton
Logged
Pages: [1]
« previous next »