What causes KUKA Robot alarm KRC0257?

Sensor location search was interrupted or not executed after controller startup or axis replacement. $ROBCOR.DAT calibration file is missing, deleted, or located in an incorrect directory. Corrupted or invalid calibration data in $ROBCOR.DAT preventing proper axis offset recognition. Reference switch (sensor) malfunction or misalignment on the specified axis. Power loss or emergency stop activated during a previous sensor location search operation.

How do I fix KUKA Robot alarm KRC0257?

1. Verify that $ROBCOR.DAT exists in the correct location (typically $CUSTOM\KRC\Roboter\) by checking file system and restoring from backup if necessary 2. Execute the sensor location search (Referenzfahrt) for the affected axis using the teach pendant, ensuring no obstructions and proper sensor functionality 3. Check the reference switch (Referenzsensor) on the specified axis for proper mechanical alignment and electrical continuity using a multimeter 4. Inspect axis wiring harness and connectors for damage, loose connections, or corrosion that could prevent sensor signal detection 5. If $ROBCOR.DAT cannot be recovered, perform a complete robot recalibration using KUKA calibration procedures and re-execute sensor location search for all axes 6. Verify controller memory is not full and system time/date settings are correct, then power cycle the controller and retry sensor location search

KUKA Robot codes

axismd.ai

KUKA Robot Controller

Servo/Axis · Basic

Alarm KRC0257

KUKA Robot KRC0257 - PERFORM SENSOR LOCATION SEARCH <axis number> !

This alarm indicates that the sensor location search (Referenzfahrt) was not completed for the specified axis, or the robot calibration data file $ROBCOR.DAT is missing or corrupted. The robot cannot operate safely without proper axis calibration and sensor offset values stored in the calibration file. The axis must be referenced against its mechanical zero position using the sensor location search routine before normal operation can resume.

KUKA RobotServo/AxisBasic

KRC0257

KUKA Robot KRC0257 - PERFORM SENSOR LOCATION SEARCH <axis number> !

PERFORM SENSOR LOCATION SEARCH <axis number> !

Common Causes

Sensor location search was interrupted or not executed after controller startup or axis replacement
$ROBCOR.DAT calibration file is missing, deleted, or located in an incorrect directory
Corrupted or invalid calibration data in $ROBCOR.DAT preventing proper axis offset recognition
Reference switch (sensor) malfunction or misalignment on the specified axis
Power loss or emergency stop activated during a previous sensor location search operation

Troubleshooting Steps

1Verify that $ROBCOR.DAT exists in the correct location (typically $CUSTOM\KRC\Roboter\) by checking file system and restoring from backup if necessary
2Execute the sensor location search (Referenzfahrt) for the affected axis using the teach pendant, ensuring no obstructions and proper sensor functionality
3Check the reference switch (Referenzsensor) on the specified axis for proper mechanical alignment and electrical continuity using a multimeter
4Inspect axis wiring harness and connectors for damage, loose connections, or corrosion that could prevent sensor signal detection
5If $ROBCOR.DAT cannot be recovered, perform a complete robot recalibration using KUKA calibration procedures and re-execute sensor location search for all axes
6Verify controller memory is not full and system time/date settings are correct, then power cycle the controller and retry sensor location search

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