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Redundancy

Increasing the plant availability

For the individual telecontrol protocols, reference was already made as to how the availability of telecontrol communication can be increased using redundant transmission paths. How- ever, as a result of seamless integration of the telecontrol technology into the SIMATIC PCS 7 process control system, the redundant design of the telecontrol communication is embed- ded in the redundancy concept of the complete system and must therefore be considered globally.

The example of a SIMATIC PCS 7 process control system with integral telecontrol linking of RTUs on the basis of

SIMATIC PCS 7

OS clients

Terminal bus

Redundant system bus

Control center

SIMATIC PCS 7 TeleControl OS with redundant servers

the IEC 870-5-101/IEC 870-5-104 protocols demonstrates the various possibilities for increasing plant availability:

• Redundant SIMATIC PCS 7 TeleControl OS servers for pro-

cess control of central and widely distributed units and for

archiving

• Redundant system bus for system communication

• Redundant telecontrol communication between control

center and RTUs over two separate transmission paths

• Redundant RTUs on the basis of S7-400H/ S7-400FH con-

trollers for local automation of remote units

• Redundant PROFIBUS for communication between control-

ler and process I/O (I/O modules, process instruments and

devices in the field)

• Redundant process I/O

TCP/IP to serial converter

IEC 870-5-101 redundant

RTU S7-400H

ET 200M redundant with 2 x CP 341

TCP/IP

WAN router

IEC 870-5-104 redundant

 

 

 

RTU

 

 

 

 

S7-400H

 

 

 

 

 

 

 

 

with CP 443

 

 

 

 

XX 00274

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

redundant

PCS7G

 

 

 

ET 200M

 

It is also possible to implement safety-related functions in the RTU (up to SIL 3) based on the S7-400FH controller and F modules in the ET 200M remote I/O station.

Redundant telecontrol configuration based on the IEC 870-5-101/IEC 870-5-104 protocols

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Siemens SIMATICS PCS7 brochure Redundancy, Increasing the plant availability