# Robot Analog Output via RTDE

**URL:** <https://forum.universal-robots.com/t/robot-analog-output-via-rtde/716>\
**Category:** Robot Communication\
**Created:** [April 24, 2017, 12:11pm UTC](https://forum.universal-robots.com/t/robot-analog-output-via-rtde/716 "2017-04-24T12:11:14Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![anon75497214](https://avatars.discourse-cdn.com/v4/letter/a/4da419/32.png) [@anon75497214](https://forum.universal-robots.com/u/anon75497214)\
**Post date:** [April 24, 2017, 12:11pm UTC](https://forum.universal-robots.com/t/robot-analog-output-via-rtde/716/1 "2017-04-24T12:11:14Z")

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Hi,

I want to set one of the analog standard outputs AO0, AO1 via RTDE.

The RTDE documentation says about the standard\_analog\_output\_0 the following: `Standard analog output 0 (ratio) [0..1]`  
Now, what does ratio mean? I just want to specify the voltage for that port. Does this mean adjusting the value to be between 0 and 1 and 1 being 10 Volt?

Additionally: What is the minimum set of variables that need to be set to do this? I suppose standard\_analog\_output\_type being one of them.

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**Author:** ![jbm](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.universal-robots.com/jbm/32/614_2.png) [@jbm](https://forum.universal-robots.com/u/jbm)\
**Post date:** [April 25, 2017, 5:53am UTC](https://forum.universal-robots.com/t/robot-analog-output-via-rtde/716/2 "2017-04-25T05:53:42Z")

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Yes.  
However whether 0.0 and 1.0 being respectively 4 mA or 0 V and 20 mA or 10 V is depending on the value of the AOT (analog output type) bits. But it is ratio of full scale out.

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<div class="post-metadata">

**Author:** ![anon75497214](https://avatars.discourse-cdn.com/v4/letter/a/4da419/32.png) [@anon75497214](https://forum.universal-robots.com/u/anon75497214)\
**Post date:** [April 25, 2017, 9:24am UTC](https://forum.universal-robots.com/t/robot-analog-output-via-rtde/716/3 "2017-04-25T09:24:29Z")

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Thank you @jbm

Now that I connected our setup I get the error when starting up:

`SafetyA: C192A20: Safety system fault: SPI output error detected`

This happened after connecting a micro controller (attached to a small gripper) to the PWR and GND connections of the POWER TAB for power and two connectors to the AO0 and AG of the analog output.

What does this mean?

//Edit: Okay fixed that.

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<div class="post-metadata">

**Author:** ![jbm](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.universal-robots.com/jbm/32/614_2.png) [@jbm](https://forum.universal-robots.com/u/jbm)\
**Post date:** [April 28, 2017, 12:54pm UTC](https://forum.universal-robots.com/t/robot-analog-output-via-rtde/716/4 "2017-04-28T12:54:47Z")

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The SPI output error comes, if there is no 24V present, at the 24V rail.  
Typically if the jumpers between PWR and 24V are missing, loose or if an external PSU is used and is not active.