Origin	Germany
Model Number	S7-200,S7-300,S7-400
Brand Name	Siemens

S7-200:
SIMATIC S7-200 applications range from replacing relays and contactors to handling less complex automation tasks in standalone mode, in networks and within distributed configurations.
To save costs, the S7-200 is increasingly being employed in areas that previously required special electronics.
In addition to the comprehensive basic functionality of the five available CPUs a wide range of I/O and function modules provides solutions tailored to the customers requirements.

S7-300:
The connection of SIMATIC S7-300 programmable controllers via communications processors permits the direct integration of the controllers into Industrial Ethernet.
The communications processors have multi-protocol capability and support the following protocols:
Programming device communication (PG/OP)
S7 communication
S5-compatible communication (SEND/RECEIVE, FETCH/WRITE)
PROFINET
IT

S7-400:

Siemens S7-400H system including products as S7 414-4H CPU with CP443-1, S7 315-2DP CPU with CP343-5, S7 CPU 224 with EM277 (OEM cooling machine), SCALANCE X202-2 X204-2 (redundant ring Ethernet net), ET 200M distribute I/O (Y-Link contact with converter), WinCC version 6.0 Asia and SIMATIC IPC with redundant CP1613 is applied in the Equipment Monitor and Control System (EMCS) of Beijing Subway Line 5 air conditioning system. It meets customers’ requirements with its high availability system, tight time schedule to satisfy requirements during Olympic Games, comfortable and safe station environment, total integrated and open system and friendly HMI interface. With the high availability SIMATIC H system, redundant ring type Ethernet and the distribute I/O, and intelligent station, this system can reduce the possibility of system failure, and with the event synchronization principle for H system it can save the time of project engineering and commissioning. The fast system diagnostic with STEP 7 and WinCC will reduce the cost of maintenance. Besides, it can achieve the purpose of energy saving and environment protecting. Thus, it brings benefits to customers.