Siemens SINUMERIK 840D sl, Function Manual

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Detailed description
2.12 Block descriptions
Basic logic functions: PLC Basic program powerline (P3 pl)
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Function Manual, 11/2006, 6FC5397-0BP10-2BA0
2.12.12 FC 3: GP_PRAL Basic program, interruptcontrolled section
Description of Functions
Blocksynchronized transfers from the NCK to the PLC (auxiliary and G functions) are carried
out in the interruptdriven part of the basic program. Auxiliary functions are subdivided into
normal and highspeed auxiliary functions.
Highspeed auxiliary functions
•
The highspeed functions of an NC block are buffered and the transfer acknowledged to
the NC. These are passed to the application interface at the start of the next OB1 cycle.
•
Highspeed auxiliary functions programmed immediately one after the other, are not lost
for the user program. This is ensured by a mechanism in the basic program.
Normal auxiliary functions
are acknowledged to the NC only when one cycle duration has passed on it. This allows the
application to issue a read disable to the NC.
The G Functions are evaluated immediately and passed to the application interface.
NC process interrupts
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 when the FB 1 parameter
"UserIR": is = 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, jobcontrolled 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.