Siemens CPU 315-2 DP Reference Manual

Tips and Tricks
5-2
PLC S7-300, CPU Specifications CPU 312 IFM to CPU 318-2 DP
A5E00111190-01
With Backup Battery
Without Backup Battery
CPU program on Memory
Card or in the integral
EPROM of the
312IFM/314IFM
Memory card not plugged
in
All DBs are retentive,
whatever configuration has
been performed. The DBs
generated using SFC 22
“CREAT_DB” are also
All DBs (retentive,
non-retentive) are transferred
from the memory card or from
the integral EPROM into RAM
on restart.
The DBs configured as
retentive retain their contents
retentive.
 Data blocks or data areas you have generated with
SFC22 ”CREAT_DB” are not retentive.
 After a power failure, the retentive data areas are retained.
Note:These data areas are stored in the CPU, not on the
memory card. The non-retentive data areas contain
whatever has been programmed on EPROM.
Watchdog Interrupt: Scan period > 5 ms
For the watchdog interrupt, you should set a scan period > 5 ms. With lower values
the risk of frequent occurrence of watchdog interrupt errors increases, for example,
depending on
 The program cycle time of an OB35
 Frequency and program cycle time of higher priority classes
 Programming device functions.
Hardware Interrupts Generated in I/O Modules
When using applications critical to hardware interrupt, insert the
hardware-triggering modules as close to the CPU as possible.
Reason: Interrupts generated in module rack 0, slot 4, are read first. The other
slots follow in ascending order.

Siemens CPU 315-2 DP Specifications

General

Memory	64 KB
Power Supply	24 V DC
Order Number	6ES7 315-2AG10-0AB0
Number of DP Masters	1
Number of DP Slaves	124
Load Memory	64 KB
Number of Timers	256
Number of Counters	256
Data Memory	64 KB
Operating Temperature	0 to 60 °C
Integrated Interfaces	MPI, DP
Digital Outputs	Not integrated
Analog Inputs	Not integrated
Analog Outputs	Not integrated
Programming Languages	LAD, FBD, STL
Digital Inputs	Not integrated
Weight	660 g