4. Troubleshooting¶

URCap not installed / no green hook¶

• After adding the URCap under System → URCaps → +, you must restart the robot. The URCap only shows the green hook after a successful reboot.
• Use a freshly formatted USB stick for the URCap file.
• Confirm the robot is a UR E-series running Polyscope 5.22 or newer. The CB-series is not supported.

No connection to the Machine Vision Device¶

The Connection tab LED is red or the connection status is red:

• Check the cables and the network setup — the robot and the Machine Vision Device must be in the same network.
• Verify the IP address (default 192.168.100.1) and port (default 6008) in the Connection tab.
• Make sure RTDE (Real Time Data Exchange) is enabled in the UR security settings.
• Ensure the robot server on the device is active with UR Polyscope 5 URCap selected as the robot manufacturer (device website → Jobs → Robot Server). See Settings on Device Website in the wenglor robot vision manual.

Processing Instance or Device Robot Vision status is red¶

• Processing Instance red: Check the status of the Processing Instance on the device website of the Machine Vision Device.
• Device Robot Vision red: There is no Device Robot Vision module in the current uniVision job. Add it to the job.

Cannot start the calibration¶

Calibration can only be started when the Calibration tab system status LED is green:

Calibration incomplete (camera not on robot)¶

• A yellow Calibration tab LED can mean the second calibration step is missing. For camera-not-on-robot, place the calibration target on the object plane and trigger the second step (one image is captured). See User Configuration → Camera not on robot.
• Calculating the calibration results takes some time — wait until it completes.

Insufficient calibration accuracy¶

• Use more than five calibration poses (seven to eleven give better results). Set the count in the Calibration options tab.
• Increase the variation between poses — the variance of the calibration movements matters more than the variance of the poses.
• Make sure the calibration target covers as much of the camera image as possible and is fully visible.
• Prefer a wenglor ZVZJ calibration target and select the correct target size.

For the general calibration guidelines, see the Wenglor Robot Server overview in the wenglor robot vision manual.

Detection pose issues (camera on robot)¶

• For camera on robot, the robot must be moved to the detection pose from the URCap, which is identical to the first calibration pose. To update it, set the detection pose on the URCap installation page and re-run the calibration process.

w_ref_frame update is lost after restart¶

• w_ref_frame is saved in the installation, not in the program. Save the installation before shutting down the robot.
• Because the program reads installation feature values only at program start, an Assignment node is required to update w_ref_frame within the program run. See Robot Program → update_reference_frame.

Error codes returned by the device¶

If the robot server returns a negative error code (-5001 … -5010), it indicates a problem on the vision-device side. For the meaning of each code, see the Generic Robot Vision Interface → Error codes in the wenglor robot vision manual.