Marker/Counter Variables - Siemens SINUMERIK 840Di sl Function Manual

2.3.1

Marker/counter variables

Channel-specific markers
The array variable $AC_MARKER[n] is used as a marker or counter and can be read and
written in synchronized actions.
Data type: INTEGER
n: Field index of the marker: 0–n
The number of markers per channel is set using machine data
MD28256 $MC_NUM_AC_MARKER.
In the machine data 28256: $MC_NUM_AC_MARKER the
maximum value that can be specified is 20000.
One element requires 4 bytes. You must ensure that sufficient memory of the correct type is
available. These markers exist once in each channel under the same name. The memory
location for $AC_MARKER[n] can be selected with the machine data
MD28257 $MC_MM_BUFFERED_AC_MARKER with
0: in the dynamic memory (active file system)
1: in the static memory (passive file system)
can be selected.
Markers stored in the static memory can be included in the data backup.
front panel. See 2.3.7
On Power On, NC Reset, and End of Program, the markers are set to 0.
This ensures the same start conditions for every program run.
General procedure
In addition, for SW 6.3 and higher
It is possible to select the memory location for $AC_MARKER[n] between DRAM and SRAM
with the following machine data:
MD28257 $MC_MM_BUFFERED_AC_MARKER ($AC_MARKER[] is saved in SRAM)
0: dynamic memory DRAM, (default)
1: static memory SRAM
20000 can be specified as the highest value in the machine data:
MD28256 $MC_NUM_AC_MARKER (dimension of $AC_MARKER)
One element requires 4 bytes. You must ensure that sufficient memory of the correct type is
available.
Markers saved in SRAM can be included in the data backup. See Chapter "System variables
saved in SRAM (SW 6.3 and later)"
Synchronized actions
Function Manual, 11/2006, 6FC5397-5BP10-2BA0
2.3 Special real-time variables for synchronized actions
Detailed description
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