Motorola 68P02958C00-B - Manual (Page 23)

System Overview
2-3
The IP Gateway allows the SCADA center to conduct a large number of sessions via a large
number of logical channels in spite of a single physical RS-232 port. The IP Gateway also
serves as an MDLC router between the MOSCAD Programming Toolbox and RTUs.
The Toolbox may be connected either locally to an RTU or via the MDLC port of the IP
Gateway to any RTU in the system. All programming and monitoring functions can be
performed either locally or remotely.
Note: The MOSCAD Programming Toolbox that is connected locally to one of the RTUs in
the system can service any other RTU in the system via the communication network.
Figure 2-2 describes multiple SCADA control centers which are connected to the IP Gateway
via a 10 Mbps Ethernet LAN. In this case, multiple TCP/IP logical links are used for
communicating with the IP Gateway, which is connected via multiple MOSCAD CPUs to
multiple MDLC links (Radio link, Line link, Dial-up link etc.).
Multiple SCADA control centers can simultaneously perform multiple sessions with the IP
Gateway in order to send commands and polling requests to the RTUs and to receive data and
contention reports from the MOSCAD RTUs.
SCADA
Computer
TCP/IP on Ethernet
RTU
Wire Line Dial up Modem
RTU RTU RTU RTU
RTU
RTU
RTU
MDLC on R 485 S
MDLC on Radio
MOSCAD
Leased
Line
Work Stations
SCADA
Computer
RS232
MOSCAD
ToolBox
Figure 2-2: SCADA Control Center with Multiple Links-Based MOSCAD System