Good day

Is there a way to reset QRACKF without forcing the output to 0 on OB_DIAG1 Block. This fault normally comes up after DP slave power failure.

Dear VeeKy, 

The group error message QRACKF indicates failure of the DP master or slave. 
So it usually  indicates a “real” error of the PROFIBUS system.

If there is no real error or the error is no longer pending and the block has not been updated, this may indicate an  incorrect block version. 
In that case kindly check your block versions against the library and in case upgrade according FAQ: https://support.industry.siemens.com/cs/ww/en/view/109977722

If QRACKF remains set after a DP slave power failure, first check your PCS 7 and Basis Library version. This issue is known in older releases and was improved in PCS 7 V9.1 SP2 Update 2 or newer, where diagnostic flags like QRACKF and QMODF clear automatically once hardware is healthy. If you can’t update immediately, review the OB_DIAG1 configuration, diagnostic buffer, and compare online block data between affected and unaffected modules. Collect software/library version details and confirm if the issue occurs only after DP power loss or in other cases. Updating to the latest Basis Library is the most effective solution.

Thank you