Technical data of CPU 31x   
7.2 CPU 312 
  CPU 31xC and CPU 31x, Technical data 
7-6  Manual, Edition 08/2004, A5E00105475-05 
Technical data 
Communication functions 
PG/OP communication  Yes  
Global data communication  Yes 
•  Number of GD circuits 
4 
•  Number of GD packets 
–  Sending stations 
–  Receiving stations 
Max. 4 
Max. 4 
Max. 4 
•  Length of GD packets 
–  Consistent data 
max. 22 bytes 
22 bytes 
S7 basic communication  Yes 
•  User data per request 
–  Consistent data 
max. 76 bytes  
76 bytes (for X_SEND or X_RCV) 
64 bytes (for X_PUT or X_GET as the server) 
S7 communication   
•  As server 
Yes  
•  User data per request 
–  Consistent data 
Max. 180 bytes (with PUT/GET) 
64 bytes 
S5-compatible communication  Yes (via CP and loadable FCs) 
Number of connections  Max. 6 
can be used for   
•  PG communication 
–  Reserved (default) 
–  Configurable 
Max. 5 
1 
from 1 to 5 
•  OP communication 
–  Reserved (default) 
–  Configurable 
Max. 5 
1 
from 1 to 5 
•  S7-based communication 
–  Reserved (default) 
–  Configurable 
Max. 2 
2 
from 0 to 2 
Routing  No  
Interfaces 
1st interface 
Type of interface  Integrated RS485 interface 
Physics  RS 485 
electrically isolated  No 
Interface power supply 
 (15 to 30 VDC) 
max. 200 mA 
Functionality 
•  MPI 
Yes 
•  PROFIBUS DP 
No 
•  Point-to-point communication 
No