Siemens SINUMERIK 840D sl Function Manual page 1388

Detailed description
2.12 Block descriptions
Data types
The data types of the NCK are listed in the NCVAR selector with the variables. The tables
below give the assignments to the S7 data types.
Classification of data types
NCK data type
double
float
long
integer
uint_32
int_16
uint_16
unsigned
char
string
bool
datetime
2.12.3 FB 3: PUT write NC variables
Description of Functions
The PLC user program can write variables in the NCK area using FB PUT. The FB is multi-
instance-capable.
Every FB 3 call must be assigned a separate instance DB from the user area.
When FB 3 is called with a positive signal edge change at control input Req, a job is started
to overwrite the NC variables referenced by Addr1 to Addr8 with the data of the PLC
operand areas locally referenced by SD1 to SD8. Successful completion of the write process
is indicated by a logical "1" in status parameter "Done".
The write process lasts for several PLC cycles (normally 1-2). The block can be called up in
cyclic mode only.
Any errors are indicated by Error and State.
In order to reference the NC variables, all required variables are first selected with the "NC
VAR selector" tool and generated as STL source in a data block. A name must then be
assigned to this DB in the symbol table.
"DB name.S7 name" is transferred as the actual parameter of the NCK variable address
(Addr1 to Addr8) when FB 3 is called.
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S 7 data type
REAL
REAL
DINT
DINT
DWORD
INT
WORD
WORD
CHAR or BYTE
STRING
BOOL
DATE_AND_TIME
Basic logic functions: PLC basic program solution line (P3 sl)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0