Siemens SINUMERIK 840D sl, Function Manual

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Detailed description
2.12 Block descriptions
Basic logic functions: PLC basic program solution line (P3 sl)
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Function Manual, 11/2006, 6FC5397-0BP10-2BA0
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
S 7 data type
double REAL
float REAL
long DINT
integer DINT
uint_32 DWORD
int_16 INT
uint_16 WORD
unsigned WORD
char CHAR or BYTE
string STRING
bool BOOL
datetime DATE_AND_TIME
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.