User Manual

32 • I/O Modules
Special Modules
WAGO-I/O-SYSTEM 750
I/O Modules
Table 10: Process data and register communication
Process data communication
Mailbox switched on Mailbox switched off
Register Communication
Control /status
(1 byte long, from byte 0)
Control /status
(1 byte long, from byte 0)
Control /status
(1 byte long, from byte 0)
Used internally
(1 byte long, from byte 1)
Used internally
(1 byte long, from byte 1)
Used internally
(1 byte long, from byte 1)
Register data
(2 bytes long, from byte 2 to 3)
Mailbox
(Acyclical data,
6…18 bytes long,
from byte 2 to n)
Process data
(Cyclical data,
0…32 bytes long,
from byte n + 1 to m)
(Pay attention to the valid-
ity of the data!)
Process data
(Cyclical data,
0…32 bytes long,
from byte 2 to m)
Invalid data
(from byte 4 to m)
The possible settings with regard to the overall process image and mailbox
size are explained in the following graphic.
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
Mailbox
6 byte
= 0x20Control/status
Mailbox
18 byte
= 0x20Control/status
Mailbox
12 byte
= 0x20Control/status
Register data 2 byte Control/status = 0x80
Process data length
12 byte
Process data length
24 byte
Process data length
48 byte
Control/status byte
Reserved
Process data 12-46 byte Control/status = 0x00
Figure 9: Superimposition of the mailbox and register data on the process data g064408e