Siemens Simatic S7-400 - Manual (Page 591)

Diagnostic Data of the Signal Modules
B-17
S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
Bytes 8 to 23 of the SM 431; AI 8 RTD 16 Bit
Data record 1 with bytes 8 to 23 contains channel-specific diagnostic data. The
following figure shows the assignment of the even diagnostic bytes (bytes 8, 10, to
22) for a channel of the module.
7 6 0
Configuring/parameter assignment error
Wire break
Underflow
Overflow
5 4 3 2 1
0 0 0 0
Figure B-22 Even Diagnostic Byte for a Channel of the SM 431; AI 8 x RTD x 16 Bit
The following figure shows the assignment of the odd diagnostic bytes (bytes 9,
11, to 23) for a channel of the module.
7 6 0
User connection not wired
Run time calibration error
Underrange or overrange
5 4 3 2 1
0
Open conductor in + direction
Open conductor in – direction
Open conductor in the current source
User calibration doesn’t correspond to the parameter assignment
Figure B-23 Odd Diagnostic Byte for a Channel of the SM 431; AI 8 x RTD x 16 Bit