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Troubleshooting Fieldbus Communication Loss with Miller Deltaweld

Resolve fieldbus communication loss with your Miller Deltaweld power source

Doug Ayers avatar
Written by Doug Ayers
Updated this week

The Miller Deltaweld power source communicates with the robot controller over a modbus network connection. When the power source cannot talk with the robot controller then the error "COMMUNICATION LOSS" may be displayed on the teach pendant's display.

In this article, you'll learn how to check and fix common causes to this problem.

Restart the Power Source

If you've recently made changes to the robot's network settings or reconnected the power source's network cable to the robot's controller, simply restarting the power source may re-establish the connectivity.

Check the Power Source's Network Cable

Ensure that the network cable is firmly connected to both the power source and the receptacle port on the robot's cabinet. The power source comes with a screw-in type, industrial network cable. Align the pins correctly then screw the cable into place.

Check the Robot's USB-to-Ethernet Adapter

Inside the robot's cabinet is a USB-to-Ethernet adapter that bridges the fieldbus network port from the outside of the robot cabinet to the robot controller. Ensure the network cable is firmly connected to the adapter and that the adapter is firmly connected to the robot controller. You should see either a solid or a blinking light on the adapter.

Check that Modbus TCP Service is Enabled

  1. On the teach pendant, navigate to Settings > Security > Services.

  2. Ensure the Modbus TCP interface is enabled. You may need to enter the admin password to make any changes.

  3. If you enabled the service, reboot the robot for the change to take effect.

Check the Fieldbus Modbus I/O Setup

  1. On the teach pendant, navigate to Installation > Fieldbus > MODBUS.

  2. There should be one MODBUS unit with one signal defined.

    1. The unit's IP address should be 192.168.181.151.

    2. The signal's Type should be Digital Input.

    3. The signal's Address should be 0.

    4. The signal's Name should be MODBUS_1.

  3. If you see other units, tap the Delete Unit button until all others are removed.

  4. Note the color of the dot to the left of the Type input.

    1. A green dot 🟢 indicates the modbus network is connected.

    2. A gray dot ⚪️ indicates the modbus network is disconnected.

      1. Reboot the power source.

      2. If the modbus network does not reconnect, check the eth1 network settings.

Check that Fieldbus Profinet Device is Disabled

  1. On the teach pendant, navigate to Installation > Fieldbus > PROFINET.

  2. Ensure the Profinet IO Device is disabled.

  3. If you disabled the device, reboot the robot for the change to take effect.

Check that Fieldbus EtherNet/IP Adapter is Disabled

  1. On the teach pendant, navigate to Installation > Fieldbus > EtherNet/IP.

  2. Ensure the EtherNet/IP Adapter is disabled.

  3. If you disabled the adapter, reboot the robot for the change to take effect.

Check the Robot's eth0 and eth1 Network Settings

  1. On the teach pendant, navigate to Installation > URCaps > Beacon.

  2. You should see an eth0 and an eth1 setting, each with their own IP address.

  3. If you don't see eth1, or eth1 is not assigned to 192.168.181.149, recreate the eth1 network interface.

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