Hi,

I am working on a project where at a particular position, three robots were meeting each other. I should restrict or make wait of two robots when one robot reaches such position and until finish, it works.

Robots: UR5. Series: CB3.1 SW: 3.10 for all 3 robots.

Suggest me a better way to do it: Modbus connection or EthernetIP connection or Digital IO
I cannot Use ROS or any other software. But individual Beckhoff PLC using EthernetIP is the Master for individual robots
@matthewd92  

I’d use ethernetip and just use a bit on each of the robots that the area is clear for work, when a robot gets there it notifies the PLC by triggering a bit and then the others have to wait until it’s clear. The other way to do this is monitor the positions of the robots via the position registers on the PLC and as long as the area is clear robots are free to enter, when they enter you change the area clear bit to false. 

Is it possible for two robots to want to enter the area at the same time, I.e, be waiting while the third one is already there working?  If so, you’ll also need to let the two waiting know which one is supposed to go first.