Nelson Mandela Metropolitan Municipality employs the SSE RTU-10 Telemetry System in combination with the SAN People EtherPAD Duo
for Monitoring and Control of their Sewage Network.
The Nelson Mandela Metropole have identified that the basic municipal services such as water, sewage and electricity, require
efficient management, with future demands in mind, as the large-scale development of the Koega Project proceeds.
SSE's Cape Town Branch was established in September 2001. It has since made huge inroads into the Telemetry market in the Western
Cape. The Nelson Mandela Metropolitan Municipality Sewage Network is the largest Sewage Telemetry Contract to go out to tender for
many years in the Eastern Cape, if not the biggest of its kind to be installed under one contract.
Three Adroit SCADA Master Stations provide operational and statistical information. Operations include pump trips, alarms, sump
levels and intrusion alarms. Management of the system becomes easier if this can be done centrally. Statistical data provide
valuable information for future planning of demands brought about by predicted domestic and industrial growth.
The SSE RTU-10 Telemetry system currently monitors and controls 68 pump stations. Data being logged includes flows, pipe pressure
and sump levels. The SSE RTU-10 is OPC compliant allowing connectivity to all OPC compliant SCADA's such as Adroit, Citect and
many others.
MDS Digital Data Radios (imported by SSE) provide the medium for a wide area network. Data from the 68 sewage outstations is sent
to the Adroit SCADA Master Stations. The MDS radios have a fast key-up time (7 ms) and higher data rate (4800 baud) compared to
analog radios (typically 150 ms at 1200 baud). The Master Station SCADA will be able to refresh polled data from the 68 outstations
(2000 I/O points) in approximately 80 to 120 seconds.
The telemetry hardware includes a repeater at the Central station. The SCADA Master Stations consist of three high-spec PC's connected
to the network. The cabling requirements between the Central hardware were two RS232 connections (digital radio data) and one LAN link
(connecting to the remote PC via the WAN). The problem arose when the cabling became too long for standard RS232 specification (9th
Floor to 13th Floor). This was compounded by the fact that the Central was to be moved to the next building (17th Floor).
SSE Data chose the SAN People EtherPad Duo to provide the serial connectivity solution. The Duo links two serial ports to a standard
TCP/IP network. In this application, one Duo re-directs the PC's RS232 Ports to an IP Address on the network, and another is connected
to the LAN at that IP Address, and re-creates the RS232 Ports at the remote point.
By using this method, the cabling between the PC's and the Central station hardware is reduced to one UTP LAN cable. Furthermore,
when the Central was moved to the other building, the Municipal LAN could be used for the link again. This eliminated the need for
any cabling, and allowed the Central and the PC's to be located anywhere in the Municipal area!
A useful spin-off of using the EtherPADs in this system implementation is that the two main SCADA's could now be operated in "hot
standby". There is no need to move the RS232 cables from one PC to another, as the SCADA's are both on-line at all times! A further
spin-off is that due to the Municipality having a permanent Internet connection, SSE Data is able to connect to the system directly,
via the Internet (i.e. from Cape Town), and offer online software support efficiently and cost-effectively.
The SSE RTU-10 and SAN People Duo are manufactured to IS0 9000 Standards and can be used in many different applications.
This system is easily upgraded as the demands of the Metropole increases.
In summary, SSE has selected the SAN People Duo to provide the ideal serial connectivity solution in a high profile Telemetry project,
for a high profile client.
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