Siemens CPU 312 - Page 117

Technical data of CPU 31xC
6.2 CPU 312C
CPU 31xC and CPU 31x, Technical Data
Manual, 01/2006 Edition, A5E00105475-06
6-5
Technical data
Number of function modules and communication
processors you can operate
• FM
Max. 8
• CP (PtP)
Max. 8
• CP (LAN)
Max. 4
Time-of-day
Real-time clock Yes (SW clock)
• Buffered
No
• Accuracy
Deviation per day < 10 s
• Behavior of the realtime clock after POWER
OFF
The clock keeps running, continuing at the time-
of-day it had when power was switched off.
Operating hours counter 1
• Number
0
• Value range
2
31
hours
(if SFC 101 is used)
• Granularity
1 hour
• Retentive
Yes; must be manually restarted after every
restart
Clock synchronization Yes
• In the PLC
Master
• On MPI
Master/slave
S7 signaling functions
Number of stations that can be logged on for
signaling functions
Max. 6
(depends on the number of connections
configured for PG / OP and S7 basic
communication)
Process diagnostics messages Yes
• Simultaneously enabled interrupt S blocks
Max. 20
Testing and commissioning functions
Status/control variables Yes
• Variables
Inputs, outputs, memory bits, DBs, timers,
counters
• Number of variables
– Of those as status variable
– Of those as control variable
Max. 30
Max. 30
Max. 14
Forcing Yes
• Variables
Inputs, outputs
• Number of variables
Max. 10
Block status Yes
Single step Yes
Breakpoints 2
Diagnostic buffer Yes
• Number of entries (not configurable)
Max. 100