Special Memory (SM) Bits
C-4
S7-200 Programmable Controller System Manual
A5E00066097-02
SMB6: CPU ID Register
As described in Table C-7, SMB6 is the CPU identification register. SM6.4 to
SM6.7 identify the type of CPU. SM6.0 to SM6.3 are reserved for future use.
Table C-7 Special Memory Byte SMB6
SM Bits
Description (Read Only)
Format
7
MSB LSB
CPU ID register
xxxxrrr r
0
SM6.4 to
SM6.7
xxxx = 0000 = CPU 212/CPU 222
0010 = CPU 214/CPU 224
0110 = CPU 221
1000 = CPU 215
1001 = CPU 216/CPU 226
SM6.0 to
SM6.3
Reserved
SMB7: Reserved
SMB7 is reserved for future use.