4. Troubleshooting¶

Quick reference — jump to the matching symptom below for details:

Symptom	Likely cause	Section
Reprojection error is high / picks are inaccurate	Too few or too similar calibration poses, poor calibration plate visibility	Insufficient calibration accuracy
Robot picks above/below the object	Height offset or wrong tool (TCP)	Height offset in detected poses
No connection / no reply from the camera	Wrong IP/port, RapidSockets disabled, robot server inactive	Communication errors
Program shows a warning with a negative number (`-5001` … `-5010`)	Device-side error, e.g. bad job name or missing calibration	Error codes returned by the device
Program exits without a clear error	Poses not taught, missing detection pose	Program exits unexpectedly

Insufficient calibration accuracy¶

Check	Action
Number of calibration poses	Teach more than five (e.g. seven to eleven give more accurate results). Follow the naming scheme and extend the pose sequence in `wenglorCalibration.runCalibration()`.
Pose variation	Vary the pose angles as much as possible — motions with non-parallel rotation axes give the most accurate results.
Calibration plate visibility	Make sure the plate covers as much of the camera image as possible and is fully visible.
Calibration plate type	Prefer the wenglor ZVZJ calibration plate over a printed version — its reprojection error is typically five times smaller. If printing, print the PDF at actual size on flat, stiff material.
Reprojection error	Check the value returned by `calibration:calculate`. Typical values are `0.1` for ZVZJ calibration plates and `0.5` for printed ones — higher values indicate a poor calibration.

Height offset in detected poses¶

Check	Action
uniVision job	Verify the height offset from the calibration target to the object in Device Robot Vision is set properly.
Tool (TCP)	Ensure the correct tool is selected — the program reads it via `GetSysData currentToolValue`.

Communication errors¶

Check	Action
Device IP/port	Verify that `W_VISION_DEVICE_IP` and `W_VISION_DEVICE_PORT` match the network configuration of the wenglor vision device (default `192.168.100.1`, port `32006`).
RapidSockets	In RobotStudio, adjust the network settings of the ABB robot controller for the public network and make sure RapidSockets is set to `YES` (Communication → Firewall Manager).
Robot server status	Ensure the robot server on the vision device is active (device website → tab `Jobs` → `Robot Server`), with ABB selected as the robot manufacturer.
Network/firewall	Check general network connectivity and firewall rules between the controller and the device.

Error codes returned by the device¶

If the robot server returns a negative error code (-5001 … -5010), the example maps it to a readable message in wenglorGlobal.setReturnError and shows it on the FlexPendant before exiting. For the meaning of each code, see the Generic Robot Vision Interface → Error codes in the wenglor robot vision manual.

Program exits unexpectedly¶

Symptom	Cause
Program exits immediately with "calibration poses are not set"	One or more of `wCalibPose1` … `wCalibPose5` is still the empty pose.
Program exits with "wDetectionPose pose is not set"	`wDetectionPose` was not taught for the `camera_not_on_robot` use case.
Program shows a warning and exits without a clear reason	No reply from the camera, or an unparseable error code. Check the device state via `state[<use_case>];`.