Siemens SIMATIC NET S7-300 User Manual

5 Configuring Communication Connections
A-122
S7-CPs for Industrial Ethernet Configuring and Commissioning
Release 01/2007
C79000-G8976-C182-07
Attributes AccessDescription
Max. CMax. Count is the
number of attempted
transmissions including the
first (1-100, default 5).ount
Modifiable
Inactivity Time The inactivity time specifies the interval after which the
connection is terminated if no sign of life is received
from the partner (6-180 s, default 30 s).
Modifiable
Window Time The window time specifies the interval at which sign of
life frames are sent. For SIMATIC NET CPs, the
window time is set to 1/3 of the inactivity time (2-60 s,
default 10 s). Sign of life frames are sent to check the
connection when there is no data traffic.
Display only
Notice
Window Time and Inactivity Time
The partner responds to a sign of life frame with a frame. They are therefore sent
to the partner at the intervals of the window time. To avoid unwanted connection
termination, the inactivity time should be at least three times as long as the
window time.

Siemens SIMATIC NET S7-300 Specifications

General

Product Type Designation	SIMATIC NET S7-300
Mounting	DIN rail mounting
Protection Class	IP20
CPU Models	Various models available (e.g., CPU 312, CPU 314)
Communication Interfaces	MPI, PROFIBUS DP
Power Supply	24 V DC power supply required. Different power supply modules available.
I/O Modules	Digital input modules, digital output modules, analog input modules, analog output modules
Programming	STEP 7 software
Supply Voltage	24V DC or 120/230V AC (depending on model)
Digital Inputs	Available via digital input modules
Digital Outputs	Available via digital output modules
Analog Inputs	Available via analog input modules
Analog Outputs	Available via analog output modules
Communication Functions	MPI, PROFIBUS DP, Ethernet (depending on model)
Protocols	MPI, PROFIBUS DP, TCP/IP (depending on model)
Operating Temperature	0°C to 60°C
Storage Temperature	70 °C
Memory	Depends on CPU model (e.g., 32 KB to 1.5 MB)