Siemens SIMATIC S7-300 Series Reference Manual page 80

CPUs
Address areas (I/O)
Peripheral address area, 1 KB/1 KB (freely
digital/analog addressable)of these are
S
distributed 1 KB/1 KB
Process image (cannot be 128/128 bytes
customized)
Digital channels max. 8192 (minus 1 byte
diagnostic address per DP
slave)/8192
S
Centralized max. 1024/1024
Analog channels max. 512 (minus 1 byte
diagnostic address per DP
slave)/512
S
Centralized max. 256/128
Configuration
Rack max. 4
Modules per module rack max. 8
Number of DP masters
S
integral 1
S
via CP 1
S7 message functions
Simultaneously active max. 50
Alarm-S blocks
Time
Real-time clock Yes
S
Backed-up Yes
S
Accuracy See Section 1.1.6
Operating hours counter 1
S
Number 0
S
Value range 0 to 32767 hours
S
Selectivity 1 hour
S
Retentive Yes
Clock synchronisation Yes
S
On PLC Master
S
CP on MPI Master/Slave
Testing and commissioning functions
Status/Modify Variables Yes
S
Variable Inputs, outputs, flags, DBs,
timers, counters
S
Number
– Monitor Variables max. 30
– Modify Variables max. 14
Force Yes
S
Variable Inputs, outputs
S
Number max. 10
Monitor block Yes
1-64
Single sequence
Breakpoint
Diagnostic buffer
S
Number of entries
(non-alterable)
Communication functions
PD/OP communication
Global data communication
S
Number of GD packets
– Sender
– Receiver
S
Size of GD packets
– Number of which
consistent
S7 basic communication
S
User data per job
– Number of which
consistent
S7 communication
S
User data per job
– Number of which
consistent
S7-compatible
communication
S
User data per job
– Number of which
consistent
Standard communication
S
User data per job
– Number of which
consistent
Number of connection
resources
S
Reservation for
– PD communication
User-definable
Default
– OP communication
User-definable
Default
– S7 basic
communication
User-definable
Default
Routing connections
PLC S7-300, CPU Specifications CPU 312 IFM to CPU 318-2 DP
Yes
2
Yes
100
Yes
Yes
1
1
max. 22 bytes
8 bytes
Yes (server)
max. 76 bytes
32 bytes for X/I_PUT/_GET;
76 bytes for
X_SEND/_RCV
Yes
max. 160 bytes
32 bytes
Yes (via CP and loadable
FC)
Dependent on CP
Dependent on CP
Yes (via CP and loadable
FC)
Dependent on CP
Dependent on CP
12 for PD/OP/S7 basic/S7
communication
max. 11
from 1 to 11
1
max. 11
from 1 to 11
1
max. 8
from 0 to 8
8
max. 4
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