Parameter F_CRC_Length Does Not Match Generated Values

What does 42 mean?

The 'F_CRC_Length' parameter configured for PROFIsafe communication does not match the CRC length value generated internally by the device. This inconsistency in CRC configuration will lead to failed CRC checks, causing communication errors and compromising the integrity of safety data. Reliable safety communication cannot be established under these conditions.

• The F_CRC_Length parameter was manually set to an incorrect value in the PLC programming software (e.g., CRC1 instead of CRC2 or vice versa).
• Mismatch between the PROFIsafe protocol version used by the safety PLC and the connected safety I/O device, leading to different expected CRC lengths.
• Corrupted device description file (GSDML) for the safety I/O device, causing incorrect CRC length defaults to be applied.
• Firmware update on either the PLC or the I/O module changed the default or supported F_CRC_Length values.

Click steps to track your progress.

1. 1

   Access the PROFIsafe communication parameters in the PLC programming software for both the safety PLC and the connected safety I/O device.

2. 2

   Ensure that the F_CRC_Length parameter (e.g., CRC1, CRC2) is identically configured on both ends of the PROFIsafe communication link.

3. 3

   Consult the documentation for the specific safety devices to determine the recommended or default F_CRC_Length value.

4. 4

   Recompile the safety PLC project and download the updated configuration to all affected safety devices.

5. 5

   Verify network communication using diagnostic tools to check PROFIsafe telegram integrity.