Siemens SINUMERIK 828D Function Manual page 427

auxiliary function. This means it is possible to distinguish between predefined and user-defined auxiliary
functions in the PLC user program.
Note
A change in machine data MD22254 and/or MD22256 may require corresponding
adjustment of the PLC user program:
Specific NC/PLC interface signals
The following specific NC/PLC interface signals are available:
• DB21, ... DBX318.5 (associated M00/M01 active) feedback signal
• DB21, ... DBX30.5 (activate associated M01) activation signal
Boundary conditions
Please note the following boundary conditions:
• A user-defined auxiliary function may not be multiply associated.
• Predefined auxiliary functions (e.g. M3, M4, M5 etc.) may not be associated.
Example
Associating the user-defined auxiliary function M123 with M0:
MD22254 $MC_AUXFU_ASSOC_M0_VALUE = 123
The user-defined auxiliary function M123 thus has the same functionality as M0.
Basic Functions
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
H2: Auxiliary function outputs to PLC
8.4 Associated auxiliary functions
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