Applicable Systems
TNC 620
Symptoms
A PLC I/O error was detected. Error Err 72 is displayed on the Heidenhain TNC.
Possible Causes
- Heidenhain TNC control system fault
- Program or parameter error
- Hardware component failure
- Environmental or operational factor
Troubleshooting Steps
- Step 1: Read the alarm message on the Heidenhain TNC display for error 72
Alarm text displayed with description - Step 2: Consult the Heidenhain TNC error manual for the specific error code
Error cause and remedy described in manual - Step 3: Investigate and correct the fault per the manual's diagnostic procedure
Root cause identified and corrected - Step 4: Acknowledge and clear the alarm with the ENT key or NC START
Alarm clears after fault correction
How to Reset
Correct the fault, then acknowledge the alarm with the ENT key. For persistent errors, power cycle the TNC control. Refer to the Heidenhain TNC 640 Error Manual for detailed procedures.
Frequently Asked Questions
- Q: What does Heidenhain error 72 mean?
PLC I/O Error: A PLC I/O error was detected.
- Q: How do I clear Heidenhain TNC errors?
Correct the fault described in the error message, then acknowledge the alarm with the ENT key. For critical errors, power cycle the control after addressing the root cause.
Source: Heidenhain TNC 640 Operating Manual, Dr. Johannes Heidenhain GmbH
Category: CNC