Using a safety relay to switch input to Safeguard Stop

Technical Questions Robot Communication
1

Hello everyone,

I am working with a project that involves a UR10e and two work stations. To have a good work flow we will use two identical work stations, so that an operator can prepare a product on one station while the robot does its thing on the other, and then switch places once they are done.

For this to work in a safe way, we want a safety scanner to stop when someone enters the zone the robot is working in. BUT we also want the operator to be able to work at the other work station without the robot stopping. The robot will pause once it is done on one side, and the operator then have to press a button before it starts working on the other work station.

My guess is that I could use the positioning of the joints to read which side the robot is on, and then send a signal to a safety relay using a digital output. Having set up a safety scanner with the two zones, the safety relay could then switch which zone is activating the Safeguard Stop.

Is this a viable solution? And is it OK to use a normal output from the robot to control the Safeguard Stop?

Best,
Tor

2

Hi Tor,
We are also looking to do the same concept with 2 zones. Have you had success with this ?

regards,
Francis

3

Hi Francis,

Yes! We actually did it exactly like I wrote in the first post, by using the joint position of the base to switch a digital output connected to a safety relay. Two safety scanners are then connected to the relay, and depending on which side the robot is on, the scanners switch between using a large zone and a tiny zone.

/Tor

4

Hi Tor,
Thanks for your reply, much appreciated.
Are the digital outputs (of the base joint position) switched on/off in a multitasking /script or only when the main program is running? (eg. ur cap ).?

Francis

5

Only when the main program is running. I actually never implemented this solution in production, so I didn’t figure out how the startup process would work, since the digital outputs are low before running the program.

/Tor

6

Hi,
ok, understood thanks. Currently investigating a realtime UR cap to handle zones switching signals. I will post here if successful.
/Francis.