Communication Problems with RSLogix

  • I'm having trouble getting my robots to talk to the PLC on a project, which is causing a few faults. The robots are setup with both Ethernet ports being used. We have a private network for the machinery to communicate on, and a public network for external devices to connect to, which is working fine. We have all of our devices running through a Hirschmann Ethernet switch, and I am able to ping the PLC from the robot through it, but not vice versa. I configured an Ethernet/IP I/O connection, but it's status is set to ONLINE instead of RUNNING. I'm sure that this is just some kind of data mismatch between the PLC project and the robot but I've looked through both and didn't get far. If screenshots or additional info is needed I am more than willing to provide.:)

    Edited once, last by gmumaugh ().

  • AD
  • Would have to see the safety setup under Ethernet I/P, but I did see you have the robot setup for 800 inputs and outputs?

    On the module properties window above, click on the Module definition area Change button, then the Connection tab, and check you standard and safety sizes.

    My PLC is 8-bit so it has 32 and 32 -- thus my robot is setup 16 and 16 (256 I/O)

    Under safety mine are 4 and 4 on both PLC and robot.

    So at 50 and 50 on robot, your PLC would have to be 100 and 100 size

    If your online and not running, that's my guess

  • Everything is set up correctly. Port 7 on the switch goes to ENET1 on the robot controller. ENET2 runs to ES1 on the base of the robot, then ES2 runs to an I/O card on the robot. The I/O card is also set up in the Ethernet I/O and is communicating over the private network.


  • After more digging I am now communicating with the PLC! The way I understand it is that we had all of our addresses set up correctly, but we needed safety communication before anything would actually talk. In ControlLogix, I had to generate and set a safety network number, which carries the safety signature and thus tells the robot that it is OK to communicate.


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