Universal Robots Forum

OSSD safety sensor at Safeguard input


We have an application where we want to trigger a safeguard stop with a OSSD safety sensor directly into the UR controller. (The sensor is a SICK IME2S12-04B4DC0). Is the safeguard input capable to take OSSD signals as input directly?

safety inputs

We wire the two OSSD outputs of the sensor to SI0 and SI1, the 24V wire to the 24V output at the safety plug and the GND wire to a GND connection in the controller.

We tried to configure one of the configurable input to trigger an emergency stop by using the sensor. On these input it works fine, but we cannot select a safeguard stop via the configurable inputs according to the manual. Will this be possible in the future or have we just missed the function?

We tested it on a UR5e with the latest software version 5.6.

Is it possible to trigger a safeguard stop with a OSSD safety device somehow?

What happened when you wired the outputs to SI0 and SI1? We’ve used OSSD before without issue so long as you power the device with the robot power source. Silly question but you removed the factory jumpers correct?

I have not tried it by my self. But when reading the manual:

OSSD Signals
All configured and permanent safety inputs are filtered to allow the use of OSSD safety equipment with pulse lengths under 3ms. The safety input is sampled every millisecond and the state
of the input is determined by the most frequently seen input signal over the last 7 milliseconds.
OSSD pulses on the safety outputs are detailed in part II.

I would assume that it should be possible to connect it directly.

What is the behavior. You are experiencing?
Have you tried measuring the electrical level when you are trying to trig the Safeguard?


We found the problem. It works fine when we use the 24V power plug in the controller instead of the 24V pin at the safety plug.

For other there experience this problem, remember to use the power supply pins in the controller and NOT at the safety plug!!