Communication blocks
Function Blocks - FM 458-1 DP
2-27
Edition 12.2004
2.3.7 S7WR, S7WR_B, S7WR_I, S7WR_D Write into the peripheral area of
the S7-CPU
S7WR
Input
―
R X
QF
BO
―
Error output
Offset
―
I OFF
Enable
―
BO EN
The function blocks, write the peripheral area (I/O) of the S7-CPU can
only run with one FM 458 application module.
The S7WR, S7WR_B, S7WR_I, S7WR_D blocks differ by the data type
at the input, which must correspond with the parameters to be written:
•
S7WR: REAL
•
S7WR_B: BOOL
•
S7WR_I: INT
•
S7WR_D: DINT
Using this block, data can be written into the net (useful) data area of the
SIMATIC S7-CPU, assigned to the FM 458
application module (periphery
input). This PE area is 128 bytes. If the enable signal is set, the input
value is accepted via the input and entered in the PE area.
The offset determines at which position in the PE area, the input value is
saved. Depending on the block- or data type, the offset is specified as
follows:
•
for REAL data type in 4 byte steps (data length).
value range of the offset: 0 . . . 31
•
for BOOL data type in 1 byte steps (data length).
value range of the offset: 0 . . . 127
•
for INT data type in 2 byte steps (data length).
value range of the offset: 0 . . . 63
•
for DINT data type in 4 byte steps (data length).
value range of the offset: 0 . . . 31
Output QF has the value 1, if an invalid offset was selected, or the block
is not configured on the FM 458 application module.
X
Input (default:
0.0)
OFF
Offset (default:
0)
EN
Enable (default:
0)
QF
Error output
(default: 0)
Symbol
Brief description
Mode of operation
I/O
