Fieldbus Controller 750-872/020-000
•
53
Process Image
WAGO-I/O-SYSTEM 750
ETHERNET TCP/IP
3.1.5.3 Example of a Process Output Image
The following figure is an example of a process output image. The
configuration includes 2 digital and 4 analog outputs. Therefore, the process
image has a total data length of 5 (4 words for the analog data and 1 word for
the digital outputs). When using MODBUS protocol, output data can be read
back with an offset of 200
hex
(0x0200) added to the MODBUS address.
Note
All output data over 256 words can be read back with an offset of 1000
hex
(0x1000) added onto the MODBUS address.
B
i
t 1
B
i
t 2
Word2
Word1
Word2
Word1
Word2
Word1
Word2
Word1
Word2
Word1
Word2
Word1
0x0003 / 0x0203 %
Q
W3
0x0002 / 0x0202 %
Q
W2
0x0001 / 0x0201 %
Q
W1
0x0000 / 0x0200 %
Q
W0
0x0004 / 0x0204 %
Q
W4
0x0203 %
Q
W3
0x0202 %
Q
W2
0x0201 %
Q
W1
0x0200 %
Q
W0
0x0204 %
Q
W4
0x0000 / 0x0200 %
Q
X4
.
0
0x0001 / 0x0201 %
Q
X4
.
1
0x0200 %
Q
X4
.
0
0x0201 %
Q
X4
.
1
O
N
LINK
Tx
D
/
R
x
D
E
RROR
Et
herne
t
7
50
-
8
4
2
WA
GO
ß
I/
O
ß
S
Y
S
TE
M
AO
DO
AO
Hi
ghb
yte
Lowbyte
Hi
ghbyte
Lowbyte
M
ODBUS addresses
M
ODBUS addresses
M
ODBUS addresses
M
ODBUS addresses
Process output
i
mage
(Word)
Process
i
nput
i
mage
(Word)
Process output
i
mage
(B
i
t)
Process
i
nput
i
mage
(B
i
t)
DO: D
i
g
i
ta
l
Output
AO: Ana
l
og Output
Output modu
l
es
750
-
501
550
550
Fig. 3.1-7: Example of a Process Output Image
G012925e