Siemens SINUMERIK 840Di Function Manual page 1370

Detailed Description
2.12 Block descriptions
2.12.18 FC 12: AUXFU call interface for user with auxiliary functions
Description of functions
FC AUXFU is generally called on an event-driven basis in the basic program if the channel
transferred in the input parameter contains new auxiliary functions. The PLC user can extend
FC AUXFU with program instructions for processing his auxiliary function to avoid cyclic
polling of the channel DBs. This mechanism permits auxiliary functions to be processed on a
job-driven basis. FC AUXFU is supplied as a compiled empty block in the basic program. In
this case, the basic program supplies parameter "Chan" with the channel number. The PLC
user knows which channel has new auxiliary functions available. The new auxiliary functions
can be determined by the auxiliary-function change signals in the channel concerned.
Declaration
FUNCTION FC 12: VOID
VAR_INPUT
END_VAR
BEGIN
END_FUNCTION
Explanation of formal parameters
The table below lists all formal parameters of the AUXFU function:
Signal
Chan
2-176
Chan: BYTE ;
BE;
Type Type
I Byte
//Event control of auxiliary functions
Value range
0 to 9
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0
Remarks
No. of NC channel -1
PLC Basic Program Solution Line (P3 sl)