# RTDE script\_control\_line

**URL:** <https://forum.universal-robots.com/t/rtde-script-control-line/31533>\
**Category:** Technical Questions\
**Created:** [November 23, 2023, 6:22am UTC](https://forum.universal-robots.com/t/rtde-script-control-line/31533 "2023-11-23T06:22:16Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![jan.cremer](https://avatars.discourse-cdn.com/v4/letter/j/43a26b/32.png) [@jan.cremer](https://forum.universal-robots.com/u/jan.cremer)\
**Post date:** [November 23, 2023, 6:22am UTC](https://forum.universal-robots.com/t/rtde-script-control-line/31533/1 "2023-11-23T06:22:16Z")

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Good morning,

I have a Question regarding the script\_control\_line output from the RTDE Interface. The documentation is a bit confusing about this:

> Script line number that is actually in control of the robotgiven the robot is locked by one of the threads in the script.
> 
> If no thread is locking the robot this field is set to ‘0’. Script line number should not be confused with program tree line number isplayed on polyscope

I expected that this number reflects the program progress in some way. But essentially it seems to be always 0. I tried a normal running program in polyscope, a script send to the primary interface and interpreter mode. but nothing seems to have any effect on this number.

Could someone explain what this is for?

Thanks and best regards  
Jan