Recently I have encountered a strange issue. When I want to calibrate one of my PTs, it asks for pin code. I could not find anything in its manual. This is the first time actually. Can anyone help me clearing this issue?

 

It might vary from model to model, but it appears that for some models that the value 100 unlocks access, any other number locks access.

https://s17.postimg.org/myzd4aupr/Cerabar_PIN_number_100_for_unlock.jpg