Siemens SINUMERIK 828D Function Manual page 1098

P4: PLC for SINUMERIK 828D
14.3 Programming
Interrupt programs
Interrupt programs are used to be able to handle special process conditions or requirements. The PLC828 makes
a differentiation as follows:
Condition
Shortest response time: Executed in
the servo cycle
Executed before MAIN, after reading
the inputs
Executed after MAIN, before writing to
the outputs
Interrupt programs cannot be renamed, but they can be assigned to data classes.
The interrupt program is inserted in the
project by double clicking on the
corresponding name in the operation tree:
"Libraries" > "Interrupt programs".
The PLC firmware then automatically makes
the call.
Exiting program organizational units
As a result of the described program organization (each POU occupies its own tab), it is quite clear where MAIN
and the individual sub and interrupt programs end; this is the reason that they do not require any special end
delimiter.
See also
Addressing Addressing [Page 1102]
Type of memory Type of memory [Page 1099]
1098
Program Description
INT_0 For extremely fast responses to events, which absolutely required
this. In INT_0, the direct access commands, that either access an
internal, I/O image updated in the servo cycle or only the hardware
of the onboard IO, can be practically used.
Data class: "Manufacturer"
Note:
The size of block INT_0 is limited to 500 operations.
INT_100 Especially to marshal data that is read accessed in the additional
cycle.
Data class: "Individual"
INT_101 Especially when marshaling data that were previously written in
the PLC cycle, but which should be output to other or additional
outputs.
Data class: "Individual"
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
Basic Functions