Specifications

CPUs
1-67
PLC S7-300, CPU Specifications CPU 312 IFM to CPU 318-2 DP
A5E00111190-01
Address areas (I/O)
Peripheral address area,
digital/analog
2 KB/2 KB (freely
addressable)
 Distributed 2 KB/2 KB
Process image (cannot be
customized)
128/128 bytes
Digital channels max. 16384 (minus 1 byte
diagnostic address per DP
slave)/16384
 Centralized max. 1024/1024
Analog channels max. 1024 (minus 1 byte
diagnostic address per DP
slave)/1024
 Centralized max. 256/128
Configuration
Rack max. 4
Modules per
Rack
max. 8
Number of DP masters
 integral 1
 via CP 1
S7 message functions
Simultaneously active
Alarm-S blocks
max. 50
Time
Real-time clock Yes
 Backed-up Yes
 Accuracy See Section 1.1.6
Operating hours counter 1
 Number 0
 Value range 0 to 32767 hours
 Selectivity 1 hour
 Retentive Yes
Clock synchronisation Yes
 On PLC Master
 On MPI Master/Slave
Testing and commissioning functions
Status/Modify Variables Yes
 Variable Inputs, outputs, flags, DBs,
timers, counters
 Number
– Monitor Variables
– Modify Variables
max. 30
max. 14
Force Yes
 Variable Inputs, outputs
 Number max. 10
Monitor block Yes
Single sequence
Breakpoint
Yes
2
Diagnostic buffer Yes
 Number of entries
(non-alterable)
100
Communication functions
PD/OP communication Yes
Global data communication Yes
 Number of GD packets
– Sender 1
– Receiver 1
 Size of GD packets max. 22 bytes
– Number of which
consistent
8 bytes
S7 basic communication Yes
 User data per job max. 76 bytes
– Number of which
consistent
32 bytes for X/I_PUT/_GET;
76 bytes for
X_SEND/_RCV
S7 communication Yes (server)
 User data per job max. 160 bytes
– Number of which
consistent
32 bytes
S7-compatible
communication
Yes (via CP and loadable
FC)
 User data per job Dependent on CP
– Number of which
consistent
Dependent on CP
Standard communication Yes (via CP and loadable
FC)
 User data per job Dependent on CP
– Number of which
consistent
Dependent on CP
Number of connection
resources
12 for PD/OP/S7 basic/S7
communication
 Reservation for
– PD communication
User-definable
Default
max. 11
from 1 to 11
1
– OP communication
User-definable
Default
max. 11
from 1 to 11
1
– S7 basic
communication
User-definable
Default
max. 8
from 0 to 8
8
Routing connections max. 4