Siemens Simatic S7-300 CPU 31xC and CPU 31x S7-300 User Manual
Page 172

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