Diagnostic Data of the Signal Modules
B-14 S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
B.5 Diagnostic Data of the Analog Input Modules
as of Byte 2
The structure and contents of the different bytes of the diagnostic data for the
special analog input modules are described below. The following general rule
applies: When an error occurs, the bit concerned is set to ”1”.
You will find a description of possible error causes and appropriate remedies in the
section called on the special module.

Bytes 2 and 3 of the SM 431; AI 16 16 Bit

Byte 2
76 0
Measuring range module incorrect or missing
Operating status 0: RUN
1: STOP
54321
0
Byte 3
76 0
EPROM error
RAM error
ADC/DAC error
Hardware interrupt lost
54321
0
0000 0
000
Figure B-17 Bytes 2 and 3 of the Diagnostic Data of the SM 431; AI 16 x 16 Bit