Smb8 To Smb21: I/O Module Id And Error Registers - Siemens SIMATIC S7-200 System Manual

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 D-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 D-8 Special Memory Bytes SMB8 to SMB21
SM Byte Description (Read Only)
Format Even-Number Byte: Module ID Register
m:
tt:
a:
ii:
qq: Outputs
SMB8 Module 0 ID register
SMB9 Module 0 error register
SMB10 Module 1 ID register
SMB11 Module 1 error register
SMB12 Module 2 ID register
SMB13 Module 2 error register
SMB14 Module 3 ID register
SMB15 Module 3 error register
SMB16 Module 4 ID register
SMB17 Module 4 error register
SMB18 Module 5 ID register
SMB19 Module 5 error register
SMB20 Module 6 ID register
SMB21 Module 6 error register
MSB LSB
7
m t t a i i q
Module present 0 = Present
1 = Not present
Module type
00 Non-intelligent I/O module
01 Intelligent module
10 Reserved
11 Reserved
I/O type 0 = Discrete
1 = Analog
Inputs
00 No inputs
01 2 AI or 8 DI
10 4 AI or 16 DI
11 8 AI or 32 DI
00 No outputs
01 2 AQ or 8 DQ
10 4 AQ or 16 DQ
11 8 AQ or 32 DQ
Special Memory (SM) Bits
Odd-Number Byte: Module Error Register
MSB
0 7
q c 0 0 b
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
Appendix D
LSB
0
r p f t
0 = no error
1 = error
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