Safety Inputs and NC+NO safety relay

Hi everyone.

I had a question about the Emergency and Safeguard Stop dedicated inputs on the UR-10e.
It is written in the documentation that « All safety-related I/O are constructed redundantly (two independent channels). Keep the two channels separate so that a single fault cannot lead to loss of the safety function ». And in the examples gives, all the safety relays used have two Normally Closed (NC) switches.

My problem is, In my safety relay there is one NC switch and one NO (Normally Open) switch, which is quite a common configuration.

is there a way to configure the safety inputs so they work with this type of relay ?

Greetings,

This is an interesting question. I was wondering about it as well. Have you found an answer to this? You are correct, the safeguard inputs are dual-channel, most safety relays are not - usually they are 1/2/3NO + 1 NC.

I haven’t worked with a lot of the safety switches, but some that I have seen use contacts that are stackable/replaceable, so you can add or replace with NO or NC as desired.

On the cheaper side, I just ordered some from McMaster (6785K24) which come with 2 NC contacts. This has space for a 3rd contactor so I ordered a replacement contactor to add in, as I want 2 switches for the robot E-stop and an additional one for auxiliary devices.
Our maintenance dept. had some Allen Bradley E-stop switches which can take an almost unlimited stack of contactors, but they are panel mount units and I wanted a simple enclosed box.