Data Block Control; Read_Dbl And Writ_Dbl (Read/Write A Data Block In Load Memory) Instructions - Siemens S7-1200 System Manual

8.8

Data block control

8.8.1 READ_DBL and WRIT_DBL (Read/write a data block in load memory)
instructions
Table 8- 175 READ_DBL and WRIT_DBL instructions
LAD / FBD
Table 8- 176 Data types for the parameters
Parameter and type
REQ IN
SRCBLK IN
RET_VAL OUT
BUSY OUT
DSTBLK OUT
S7-1200 Programmable controller
System Manual, 03/2014, A5E02486680-AG
SCL
READ_DBL(
req:=_bool_in_,
srcblk:=_variant_in_,
busy=>_bool_out_,
dstblk=>_variant_out_);
WRIT_DBL(
req:=_bool_in_,
srcblk:=_variant_in_,
busy=>_bool_out_,
dstblk=>_variant_out_);
Data type Description
BOOL A high signal starts the operation, if BUSY = 0.
VARIANT READ_DBL: Pointer to the source data block in load memory
WRIT_DBL: Pointer to the source data block in work memory
INT Execution condition code
BOOL BUSY = 1 signals that the reading/writing process is not complete.
VARIANT READ_DBL: Pointer to the destination data block in work memory
WRIT_DBL: Pointer to the destination data block in load memory
Extended instructions
8.8 Data block control
Description
Copies DB start values or part of the
values, from load memory to a target
DB in the work memory.
The content of load memory is not
changed during the copy process.
Copies DB current values or part of the
values from work memory to a target
DB in load memory.
The content of work memory is not
changed during the copy process.
401