Would someone please share his/her knowledge about miscellaneous codes (M codes) that are set by the machine tool builder on DMU 125P. The machine has Heidenhain iTNC530 control unit.

There are a lot of info about the general miscellaneous codes in Heidenhain manuals, however I couldnt find any information about the ones that are set by machine tool builder.

For instance, what is the meaning and effect of M51?
What are the codes for locking and unlocking of rotary axes?

I know that these are M10 and M22 (for unlocking) and M11 and M23 (for locking) of B and C axes on DMC105V. What are these codes for DMC125P?

Thanks in advance,

Metus