Siemens SIMATIC S7-200 - SMB8 to SMB21: I;O Module ID and Error Registers; Special Memory Bytes SMB8 to SMB21

Special Memory (SM) Bits
C-5
S7-200 Programmable Controller System Manual
A5E00066097-02
SMB8 to SMB21: I/O Module ID and Error Registers
SMB8 through SMB21 are organized in byte pairs for expansion modules 0 to 6.
As described in Table C-8, the even-numbered byte of each pair is the
module-identification register. These bytes identify the module type, the I/O type,
and the number of inputs and outputs. The odd-numbered byte of each pair is the
module error register. These bytes provide an indication of any errors detected in
the I/O for that module.
Table C-8 Special Memory Bytes SMB8 to SMB21
SM Byte
Description (Read Only)
Format
7
MSB LSB
Even-Number Byte: Module ID Register
Mt tAi iQQ
07
MSB LSB
Odd-Number Byte: Module Error Register
C0 0 b r P f t
0
M: Module present 0 = Present
1 = Not present
tt: 00 Non-intelligent I/O module
01 Intelligent module
10 Reserved
11 Reserved
A: I/O type 0 = Discrete
1 = Analog
ii: 00 No inputs
01 2 AI or 8 DI
10 4 AI or 16 DI
11 8 AI or 32 DI
QQ: 00 No outputs
01 2 AQ or 8 DQ
10 4 AQ or 16 DQ
11 8 AQ or 32 DQ
C: Configuration error
b: bus fault or parity error
r: Out-of-range error
P: No user power error
f: Blown fuse error
t: Terminal block loose
error
SMB8
SMB9
Module 0 ID register
Module 0 error register
SMB10
SMB11
Module 1 ID register
Module 1 error register
SMB12
SMB13
Module 2 ID register
Module 2 error register
SMB14
SMB15
Module 3 ID register
Module 3 error register
SMB16
SMB17
Module 4 ID register
Module 4 error register
SMB18
SMB19
Module 5 ID register
Module 5 error register
SMB20
SMB21
Module 6 ID register
Module 6 error register