Universal Robots Forum

Unstable behavior when pressing several times the play button

We were working on an issue when we noticed it is possible to press several times the play button.
Doing so, it looks like several process are launch and that the resulting robot program can easily be corrupted.
We were able to produce a corrupted program without any installed URCap.

We were contact by somes clients about a bug and found it were related to this since it is easy to press accidentally 2 times the play button.
Whish you could fixe this misbehavior shortly.


yes, when I was working on my UR10 as well, i do occasionally experience this problem too. The first time I press the play button, there seems to be no response, so after 1 or 2 seconds I press the play button again, only to have my first user prompt pop up, and immediately superseded by another same user prompt pop up.

I guess this is indeed one of those small trivial bugs that are recurrent enough to irritate the user/programmer, but not enough to be considered repeatable.

Version UR: 3.5.2 was the version i had


we have the same issue.
The Program gets started multiple times and the robot will react weird.
It also shows an error message regarding the communication with the joint encoders.

The movement will stop with a protecive stop without any reason.

Here are some screenshots of the behaviour:

@ajp, @jbm
Can you confirm that it is a bug ? I think it could be easy to fix and add robustness to urcaps.

I have had this happening too. And I also often get double characters when I write comments or rename program nodes, with the keyboard, maybe the two are related? Debounce set too low? Touch handling hanging?

Hi Guys, apologies for the delay, haven’t had access to a real robot for the last few days to confirm the behavior. Are we all talking about CB3 here?

CB3.1 and e-Series
It is easier with very long program but we were able to produce corrupted program with only movej nodes by pressing many times the play buttons.
In debugger we found that nothing prevent a second program processing while a first one is still on, so 2 script generation can write in the same file a the same time.

Le lun. 19 nov. 2018 à 21:32, ajp@universal-robots.com universal_robots@discoursemail.com a écrit :

I have it happening on CB2, CB3, and CB3.1, I don’t have an E to test on.

We are investigating this behavior, and are working to resolve it.

For reference, please state the explicit software version used when reporting these kind of errors.

@jbm Do you have update on this issue ?

I experienced something yesterday, maybe related to this.

On the move screen I pressed different directions quickly after each other, and after that the robot continued to move in a wrong direction, for almost a second after I released all buttons.