Siemens Simatic M7-400 Reference Manual page 582

Diagnostic Data of the Signal Modules
B.4 Diagnostic Data of the Digital Output Modules
as of Byte 2
The structure and contents of the different bytes of the diagnostic data for special
digital output 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 422; DO 16
Byte 2
Byte 3
Figure B-8
B-8
20-125 VDC/1.5 A
7 6 5 4 3 2 1 0
0 0
0 0 0 0 0
Operating status 0: RUN
7 6 5 4 3 2 1 0
0 0 0 0 0 0
0
EPROM error
Bytes 2 and 3 of the Diagnostic Data of the SM 422;
DO 16 x 20-125 VDC/1.5 A
S7-400, M7-400 Programmable Controllers Module Specifications
1: STOP
A5E00069467-07