#9 Viper_SC_Manual_
001-5008-000_Rev12e.docx |
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2.1.1
POINT-TO-POINT
A point-to-point network is the most simple of all networks, and may be used for connecting a pair of PC's, a host computer
and a terminal, a SCADA polling master and one remote, or a wide variety of other networking applications.
Figure 3 – Point to Point Network
2.1.2
POINT-TO-MULTIPOINT
A Point-to-Multipoint network is a common network type used in SCADA and other polling systems. The Master Polling
station communicates with any number of remotes and controls the network by issuing polls and waiting for remote
responses. Individual PLC/RTU remotes manage addressing and respond when their individual addresses are queried.
PLC/RTU unit addresses are maintained in a scanning list stored in the host program or master terminal device at the SCADA
host site. Communications equipment is transparent and does not interact with specific remotes; all data is coupled to the
host on a single data line (such a network is commonly used with synchronous radio modems and asynchronous radio
modems).
Figure 4 – Point to Multipoint Network
