Analog Output jumps between high (24V) and low during bootup sequence despite "Min when not running"

Steps to reproduce:

  1. Connect multimeter to Analog Output [1]. Problem is also the same if you select AO[0].
  2. Go to I/O, select AO[1] as “Voltage”.
  3. Go to Installation>I/O Setup>AO[1] and select “Min when not running”. Problem is also the same if you select “Min on unscheduled stop”.
  4. Save installation as ‘default.installation’
  5. Select Shutdown (at top right corner) and then select “Restart”

Expected Behavior:
Voltage output is expected to be 0V during the entire bootup sequence and continue to remain 0V until bootup is complete (reach the 'Initialize" page.

Actual Behavior:
During the black background phase of the bootup (the loading bar at the bottom going from 0 to 100%). The voltage output will switch to 24V between 6% to 62%, and again from 85% till completion (coming back to bright GUI page). Once it reaches the bright GUI page, the output becomes 0V and remains as 0V.

Workaround Suggestion:
No suggestions.

Robot Serial Number:

Affected Version(s):
Universal Robots Software: URSoftware (Jan 24 2022)

1 Like

On a separate note, I have used this functionality on other UR5 robots before and it works based on expected behaviour.

That’s why I know this is unexpected behaviour.

For context, I put a small buzzer (rated up to 24V) at the analog pin so that when needed during the program running, I can make short beeps at 1 volt (24 volts on the digital output is too loud).

The problem is that during bootup (start of workday) or restart, there is the occurance of the buzzer beeping that is highly irritating.

I’ve also tested on other pins such as the digital output [0] and set it as “low when not running” and they behave exactly as expected. The only reason why I do not chose digital output is that the 24V results in the buzzer going too loudly during those beeps.


Does anyone else have such a problem too as well please?

If not, could anyone with a similar robot/version help me test to see if you encounter the same issue as well too?

Thanks in advance

The same for me. I’m using the same functionality on UR10e and got the same behaviour.
This works fine on all my over UR CB3 series robots. It looks like UR e Series hardware dependant ?

Until now, I haven’t find any solution from robot side, we are working on external solution.
Did you find something ?


No I wasn’t able to resolve it, hence I have stopped using that functionality. If only UR tech support would be willing to actually respond to such issues, or at least give a response…

Software version 5.12.4 addressed the issue for the analog outputs being active on Polyscope boot sequence.

1 Like

Thank you for the update, I shall go and update my software version and test from there.