Siemens SINUMERIK 840D sl Function Manual page 409

Group assignment
The group assignment of an associated user-defined auxiliary function is always the group
assignment of the corresponding predefined auxiliary function.
Application
Associated auxiliary functions can be used in:
● Main program
● Subroutine
● Cycle
Note
Associated auxiliary functions may not be used in synchronized actions.
NC/PLC interface signals
In the case of an associated user-defined auxiliary function, the same signals are output to the
NC/PLC interface as for the corresponding predefined auxiliary function. To distinguish which
auxiliary function has actually been programmed, the value of the user-defined auxiliary
function ("value" parameter) is output as the value of the 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, 01/2015, 6FC5397-0BP40-5BA2
H2: Auxiliary function outputs to PLC
8.4 Associated auxiliary functions
409