Siemens CPU 31 Series Technical Data Manual page 67

Note
You can also use SFB 52 to SFB 54 for centralized I/O modules. SFBs 52 to 54 can also be
used for PN IO.
Reference
For further information on the blocks mentioned earlier, refer to the reference manual
System Software for S7-300/400: System and Standard Software
7Online Help
See also
PROFIBUS DP (Page 3-2)
CPU 31xC and CPU 31x, Technical Data
Manual, 01/2006 Edition, A5E00105475-06
.
Communication
3.4 DPV1
STEP
, or directly to the
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