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1MRS751852-MUM
MicroSCADA Pro
System Overview
Technical Description
SYS 600 *9.0
NETrole
Fig. 4.1.-2 Communication between a NCC (Network Control Center), SCS
(Substation Control System) and process units can be divided into
upper level communication and process communication.
4.1.1.
Upper level communication
Upper level communication means communication between the process units, the
substation control system and the network control center. There can be a SYS 500
system server or a third-party system in the network control center.
The upper level communication is usually an asynchronous serial communication
that uses telephone lines, radio links or power line carriers as the physical media.
4.1.2.
Process communication
Process communication is the communication between the substation control
system and the protection and control devices connected to the physical process. In
case there is no substation control system, the protection and control devices are
connected directly to the network control system, usually by data concentrators or
remote terminal units (RTUs). The protection and control devices are usually
connected to each other and the communication is thus called a process bus or field
bus.
Because of electromagnetic disturbances caused by the primary electric process,
optic fibres are mostly used as communication media in the process communication.
The communication line is usually faster than the one used in the upper level
communication due to the larger quantity of data.
