Predefined User Variables: Link Variables - Siemens SINUMERIK 840D sl Programming Manual

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3.1.1.4

Predefined user variables: Link variables

Link variables can be used in the context of the "NCU-Link" function for cyclic data exchange
between NCUs which are linked on a network. They facilitate data-format-specific access to the
link variables memory. The link variables memory is defined both in terms of size and data
structure on a system-specific basis by the user / machine manufacturer.
Link variables are system-global user variables which can be read and written in part programs
and cycles by all NCUs involved in a link if link communication has been configured. Unlike
global user variables (GUD), link variables can also be used in synchronized actions.
On systems without an active NCU link, link variables can be used locally on the control as
additional global user variables alongside global user variables (GUD).
Syntax
$A_DLB[<index>]
$A_DLW[<index>]
$A_DLD[<index>]
$A_DLR[<index>]
Meaning
$A_DLB:
$A_DLW:
$A_DLD:
NC programming
Programming Manual, 12/2019, 6FC5398-2EP40-0BA0
Value of the global R parameter
Type: REAL
Range of values: For a non-exponential notation:
± (0.000 0001 ... 9999 9999)
Note:
A maximum of eight decimal places are permitted
For an exponential notation:
± (1*10
Note:
● Notation: <mantissa>EX<exponent> e.g. 8.2EX-3
● A maximum of ten characters are permitted including
Link variable for BYTE data format (1 byte)
Data type: UINT
Range of values: 0 ... 255
Link variable for WORD data format (2 bytes)
Data type: INT
Range of values: -32768 ... 32767
Link variable for DWORD data format (4 bytes)
Data type: INT
Range of values: -2147483648 ... 2147483647
3.1 Flexible NC programming
... 1*10 )
-300 +300
sign and decimal point.
Work preparation
395