Siemens SINUMERIK 840D sl Programming Manual page 394

Work preparation
3.1 Flexible NC programming
The global R parameters are read and written from the user interface or in the NC program
during the preprocessing. Synchronous actions and technology cycles cannot be used.
Note
No synchronization between the channels when reading and writing global R parameters.
Because the reading and writing is performed during the preprocessing, the point in time when
a written value from one channel becomes active in another channel is not defined.
Example:
In channel 1, a loop runs with a global R parameter as loop counter. Channel 2 writes a value
to this global R parameter; this causes a loop abort in channel 1. All loops that can be
interpreted in the preprocessing in channel 1 are however still executed. The number of loops
is not defined and depends on the channel loading, etc.
The user must implement a synchronization between the channels as application, e.g. with
WAIT flags!
Syntax
Writing in the NC program
RG[<n>]=<value>
RG[<expression>]=<value>
Reading in the NC program
R...=RG[<n>]
R...=RG[<expression>]
Meaning
RG :
<n>:
<expression>:
394
Default name of the NC address for global R parameters
Note:
The name of the NC address can be set via MD15800 $MN_R_PAR‐
AM_NCK_NAME
Number of the global R parameter
Type: INT
Range of values: 0 ... MAX_INDEX
Note
MAX_INDEX is calculated from the parameterized number
of global R parameters:
MAX_INDEX = (MD18156 $MN_MM_NUM_R_PAR‐
AM_NCK) - 1
Any expression can be used as an array index, as long as the result of the
expression can be converted to the INT data type (INT, REAL, BOOL, CHAR).
Programming Manual, 12/2019, 6FC5398-2EP40-0BA0
NC programming