I am writing to inquire about configuring the safety relays for our UR3e robot. We are facing an issue with the safeguard stop that we would like to resolve.
We have installed a sensor to detect whether the safety cage door is open or closed.
The sensor is currently connected to the safeguard input, and the robot pauses correctly when the doors are opened, which is the expected behavior.
However, we are now unable to use freedrive with the door open because of the safeguard stop.
To overcome this issue, we tried using a 3-position switch setup. While this solution worked, we now need to hold the 3-position switch continuously, even when the doors are closed, which is not desirable.
We are looking for a solution that would allow us to operate the robot with the doors open in manual mode such that we can use freedrive, and move the robot with the 3-position switch held.
However, we would like to avoid having to hold the 3-position switch continuously when the doors are closed.
We would greatly appreciate your assistance in this matter and hope that a solution exists.
Did you use UR’s own 3-position setup, or an external one?
If you use UR’s own Teach Pendant with a 3-position switch, you should be able to achieve the setup you want. You have to switch between Automatic and Manual mode to achieve it.
Thanks for your reply.
We are using an external 3-position switch since our teach pendant does not have one.
How should we configure the safeguard stop such that its still “active” with the 3 position switch function enabled. We don’t want to use the 3 position switch in manual mode if the doors to the cage are already closed. As it is now the safeguard will either not be enabled at all when configured to be in automatic mode using the configurable inputs and the 3 position switch has to be held at all times, or I have to have the doors closed AND the 3 position switch held when using the normal safeguard inputs.
Ah, I’m also wrong. If you use the 3PE teach pendant, you have to hold the switch all the time while in manual mode.
How about using a safety relay to use the door safety signal in parallel with the 3 position switch? If the 3 position switch is placed inside the cage, it should be safe still.
I’m no expert in safety, so maybe someone else has a good idea on how to solve it.
You have to switch between Automatic and Manual mode to achieve it.