Detailed description 
  2.12 Block descriptions 
Power Line Basic PLC Program (P3) 
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0 
2-171 
NC process alarms 
If the interrupt is triggered by the NC (possible in each IPO cycle), a bit in the local data of 
OB 40 ("GP_IRFromNCK") is set by the basic program. (only if FB 1 parameter UserIR := 
TRUE). This data is not set on other events (process interrupts through I/Os). This 
information makes it possible to branch into the associated interrupt routine in the user 
program in order to initiate the necessary action. To be able to implement highspeed, job-
controlled processing of the user program for the machine, the following NC functions are 
available in the interrupt processing routine (OB 40 program section) for the PLC user 
program with SW 3.2 and higher: 
•  Selected auxiliary functions 
•  Tool-change function for tool-management option 
•  Position reached for positioning axes, indexing axes and spindles with activation via PLC 
•  Block transfer to FM (function available soon) 
The functions listed above can or must be evaluated by the user program in OB 40 in order 
to initiate reactions on the machine. As an example, the revolver switching mechanism can 
be activated when a T command is programmed on a turning machine. 
For further details on programming hardware interrupts (time delay, interruptibility, etc.) refer 
to the corresponding SIMATIC documentation. 
Auxiliary functions 
Generally, high-speed or acknowledging auxiliary functions are processed with or without 
interrupt control independently of any assignment.  
Basic-program parameters in FB 1 can be set to define which auxiliary functions (T, H, DL) 
must be processed solely on an interruptdriven basis by the user program.  
Functions which are not assigned via interrupts are only made available by the cyclic basic 
program as in earlier versions. The change signals of these functions are available in a PLC 
cycle.  
Even if the selection for the auxiliary function groups (T, H, DL) is made using interrupt 
control, only one interrupt can be processed by the user program for the selected functions.  
A bit is set channelspecifically in the local data "GP_AuxFunction" for the user program (if 
"GP_AuxFunction[1]" is set, then an auxiliary function is available for the 1st channel).  
The change signals and function value are available to the user in the associated channel 
DB. The change signal for this interruptcontrolled function is reset to zero in the cyclical 
basic program section after the execution of at least one full OB1 cycle (max. approx. two 
OB1 cycles).