# Use of Signal 7901 (ContactL)

**URL:** <https://tech-community.robotics.abb.com/t/use-of-signal-7901-contactl/8497>\
**Category:** Collaborative Robots\
**Created:** [October 5, 2018, 7:05am UTC](https://tech-community.robotics.abb.com/t/use-of-signal-7901-contactl/8497 "2018-10-05T07:05:56Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![yuminist](https://avatars.discourse-cdn.com/v4/letter/y/e47774/32.png) [@yuminist](https://tech-community.robotics.abb.com/u/yuminist)\
**Post date:** [October 5, 2018, 7:05am UTC](https://tech-community.robotics.abb.com/t/use-of-signal-7901-contactl/8497/1 "2018-10-05T07:05:56Z")

</div>

Hello there,

I’m trying to use the Signal 7901 (As used for ContactL in TuneMaster) for other purposes.  
Until today I thought that this signal would be MotorTorque - but this adpotion seems to be wrong.

Now I tried to figure out how to use this signal. I tried to use it with TestSignDefine and TestSignRead but it doesn’t seem to work like I was expecting.

If I am correct, I have to define it like this:  
TestSignDefine 9, 7901, ROB\_L, 6, 0;

Assuming that the channel 9 is for Nm, the signal is 7901 for the Unit ROB\_L axis 6 (and the highest sampling rate)

and if I try to read this signal I need to write:  
value:= TestSignRead(9);

Is this correct?  
The Documentation confuses me a bit…