Hello, 
I want to connect my Universal Robot UR10e emergency stop button to the emergency stop button on the machine we are integrating the robot with. We want it so that the operator could hit any of the emergency stops (the one on the robot or on the machine) and both the machine and the robot would stop. After looking in the manual (Section 5.4.2) I know that you have to use the configurable safety I/Os in order to share an emergency stop between machines. In the wiring example that is provided (pasted below), I don't understand why there are 2 wires connecting the configurable inputs to the configurable outputs other than maybe it is to make a complete circuit. We tried using one wire from the machine into the configurable input and another wire from the machine into a configurable output, but when we tried that it kept faulting and it wouldn't let me restart the robot to clear the fault. Has anyone tried to share emergency stop buttons and would be able to give me some advice?

Safety requires dual inputs/outputs to be compliant, so if you are only supplying one of the circuits you will have errors on the robot.  You can also wire the machines e-stop to the E0 and E1 blocks that are to the far left of the IO blocks, this leaves two configurable inputs free to be used as regular inputs.  But you must provide both E1 and E0 and they cannot be tied together, meaning you cant just jumper the two circuits together.  When you look at E1 and E0 you will see they have independent jumpers from the factory in them.

@matthewd92  Thank you, I did not realize that safety required dual inputs/outputs. We tried wiring the machines e-stop to the E0 block originally but it kept giving us a fault so we switched to the configurable I/Os but I didn't realize that I had to use E0 and E1 together. It sounds like we need two wires coming from the machine to the robot and two wires coming from the robot to the machine if we were to use the configurable I/Os or the Emergency Stop Blocks.   

That’s correct, the e-stop output from the robot won’t care whether you use only one of the two outputs to signal to the machine but to remain safety compliant everything needs to be redundant. The machine should want dual inputs as well. Generally if not, we will run a safety relay at the machine so that we have dual redundancy and then at least we know the signal to the machine is made correctly by the safety relay as it will only allow the signal to be sent if the two relay inputs are in sync.