Hello. Currently, we are trying to connect to our UR10e using MODBUS. Our end goal is to send an email notification when the robot encounters an emergency stop. However, we have had no success in getting MODBUS to connect on both our laptop and/or Raspberry Pi. We understand that a laptop is easier, but we would like it to work on the Pi because there is no guarantee that our laptop will always be connected/stationary in the room it is currently in. We have been trying to come up with a solution to this that does not involve us having to buy a physical and/or software product for the MODBUS interface. We have tried using free programs, all to no avail. We are able to ping the robot from our laptop and Pi, but we are having no luck with the MODBUS portion of the issue.

Has anyone else had any success in doing this? If so, could you please reach out to us and explain the steps you took to resolve this?

Have you created a modbus server on the pi?  We’ve done modbus from a pi to the robot and a Robotiq gripper but we had to write the server to listen to events and be able to respond. The UR acts as a client in this regards. 

Why not use a relay and just hook up hook up a configurable output from the robot to one of the inputs on the pi?  Then a simple python program could listen for an input and send an email when it’s triggered.  Could mount the pi directly inside the Ur control cabinet to make it easier