Siemens SINUMERIK 840D sl Programming Manual page 396

Work preparation
3.1 Flexible NC programming
$A_DLR:
<index>:
Example
An automation system contains two NCUs (NCU1 and NCU2). Machine axis AX2 is connected
to NCU1. It is traversed as a link axis of NCU2.
NCU1 writes the actual current value ($VA_CURR) of axis AX2 cyclically to the link variables
memory. NCU2 reads the actual current value transferred via link communication cyclically and
displays alarm 61000 if the limit value is exceeded.
The data structure in the link variables memory is illustrated in the following figure. The actual
current value is transmitted in the REAL value.
396
Link variable for REAL data format (8 bytes)
Data type: REAL
Range of values: ±(2.2*10
Address index in bytes, counted from the start of the link variable memory
Data type: INT
Range of values: 0 - MAX_INDEX
Note
● MAX_INDEX is calculated from the parameterized size of the
link variables memory: MAX_INDEX = (MD18700
$MN_MM_SIZEOF_LINKVAR_DATA) - 1
● Only indices may be programmed, so that the bytes ad‐
dressed in the link variables memory are located on a data
format limit ⇒
Index = n * bytes, where n = 0, 1, 2, etc.
–
–
–
–
... 1.8*10 )
-308 +308
$A_DLB[i]: i = 0, 1, 2, ...
$A_DLW[i]: i = 0, 2, 4, ...
$A_DLD[i]: i = 0, 4, 8, ...
$A_DLR[i]: i = 0, 8, 16, ...
Programming Manual, 12/2019, 6FC5398-2EP40-0BA0
NC programming