Digital Modules
4-74 S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
Terminal Assignment and Block Diagram of the SM 422; DO 32 24 VDC/0.5 A
INTF
EXTF
1L+
0
1
2
3
4
5
6
7
1M
2L+
2L+
0
1
2
3
4
5
6
7
2M
2M
3L+
3L+
0
1
2
3
4
5
6
7
3M
3M
4L+
4L+
0
1
2
3
4
5
6
7
4M
4M
1L+
1L+
2L+
Backplane bus interface
1M
2L+
3L+
4L+
3M
4M
2M
1M
+
+
+
+
3L+
4L+
Control
Diagnostics
Output status
1L+ – monitoring
Monitoring of internal voltage
Control
Channel
status
LED
L+
24 V
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
48

Process

Module

Figure 4-18 Terminal Assignment and Block Diagram of the SM 422; DO 32 24 VDC/0.5 A