Siemens SIMATIC S7-400 Reference Manual page 417

Bytes 11 to 42 of the SM 422; DO 32 x DC 24 V/0.5 A
Data record 1 contains the channel-specific diagnostic data, starting at bytes 11 to 42. The
figure below shows the assignment of the diagnostic byte for a channel of the module.
Table B-14
Bytes 11 - 42
Bytes 2 and 3 of the SM 422; DO 16 x AC 20-120 V/2 A
Table B-15
Byte 2
Byte 3
S7-400 Automation System Module Data
Reference Manual, Ausgabe 11/2016, A5E00850736-08
Diagnostic byte for a channel of the SM 422; DO 32 x DC 24 V/0.5 A
Byte Bit
7 0
6 External load voltage missing
5 0
4 Wire break
3 Short-circuit to M
2 Short-circuit to L+
1 0
0 Configuring/parameter assignment error
Bytes 2 and 3 of the diagnostic data of the SM 422; DO 16 x AC 20-120 V/2 A
Byte Bit
7 0
6 0
5 0
4 0
3 0
2 Operating mode 0: RUN; 1: STOP
1 0
0 0
7 0
6 0
5 0
4 0
3 0
2 EPROM error
1 0
0 0
B.4 Diagnostic data of the digital output modules as of byte 2
Meaning
Meaning
Diagnostic data of signal modules
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