KRC0974

Common Causes

• Attempting to read a digital input outside of an allowed program scope or interrupt handler
• Using digital input operations in a synchronous function or callback where asynchronous I/O is prohibited
• Incorrect digital input variable declaration or instantiation in restricted program sections
• Attempting digital input access before the robot control system has fully initialized I/O resources
• Using digital input statements in a library function or include file that restricts I/O operations

Troubleshooting Steps

1. 1Review the KRL program code at the location specified in the error message and identify the digital input statement causing the alarm
2. 2Check the KRL syntax documentation to verify that digital input operations are allowed in the current program context
3. 3Verify that all digital input accesses are performed in appropriate interrupt handlers or main program sections
4. 4Ensure the robot system has completed initialization before attempting any digital input read operations
5. 5Refactor the code to move the digital input operation to a permitted program location if necessary
6. 6Clear the alarm using the teach pendant and perform a full system restart to reset the I/O module state