Siemens Simatic S7-400 - Manual (Page 580)

Diagnostic Data of the Signal Modules
B-6
S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
Bytes 2 and 3 of the SM 421; DI 16 24/60 VUC
Byte 2
7 6 0
Operating status 0: RUN
1: STOP
5 4 3 2 1
0
Byte 3
7 6 0
EPROM error
Hardware interrupt lost
5 4 3 2 1
0
0 0 0 0 0 0
0 0 0 0 0
Figure B-5 Bytes 2 and 3 of the Diagnostic Data of the SM 421; DI 16 x 24/60 VUC
Bytes 4 to 8 of the SM 421; DI 16 24/60 VUC
Byte 4
7 6 0 5 4 3 2 1
Byte 5
7 0
Channel type B#16#70: digital input
Number of diagnostics bits that the module
outputs per channel: 8 bits long
Byte 6
7 0
Number of channels of the same
type in one module: 16 channels
Byte 7
7 6 0
Channel error, channel 0
Channel error, channel 1
Channel error, channel 6
Channel error, channel 7
5 4 3 2 1
...
0
Byte 8
7 6 0
Channel error, channel 14
Channel error, channel 15
5 4 3 2 1
...
Channel error, channel 8
Channel error, channel 9
Figure B-6 Bytes 4 to 8 of the Diagnostic Data of the SM 421; DI 16 x 24/60 VUC