Ekurhuleni recently signed what is believed to be the first five-year lease for telemetry and scada (supervisory control and data acquisition) equipment and maintenance in South Africa.
Ekurhuleni recently signed what is believed to be the first five-year lease for telemetry and scada (supervisory control and data acquisition) equipment and maintenance in South Africa.
System integrator and specialist in RTU/PLC (remote terminal unit/programmable logic controller) automation and process control, SSE, recently implemented this BMO (build, maintain, operate) lease for Ekurhuleni's bulk water and sewage distribution and storage network to improve efficiencies in the municipality's service delivery and operating costs.
Under the leasing agreement, Ekurhuleni purchases its data from SSE on a monthly basis freeing management and staff to focus on their core business. Everything from system call-outs to tri-monthly preventative maintenance, the continuous stream of realtime information and trouble-shooting is handled by the experts at SSE. The Operator uses Opus report writing software to poll maintenance data logged in the Adroit scada system to determine monthly billing for the lease.
The scada is used to monitor reservoir levels, flow and PRV (pressure reducing valves) at the bulk water sites. It also monitors pump trips, overflows of sumps, and conditions of the supply lines for the sewage system.
End-users can see an overview of the site from a remote desk-top by logging in to the Ekurhuleni Intranet, but most site operators prefer to receive information and alarm details via their cellular phones, enabling staff mobility while ensuring constant monitoring of the reticulation system.
Gert Bezuidenhout, group managing director for SSE says: "We chose Adroit because it is well supported, being a locally developed product. It has all the features and applications that we required for the project. One of its strengths is the ability to handle remote time stamping with SSE RTUs - seamlessly bringing data such as logging of alarms, into the database."
SSE's RTUs are installed at all Ekurhuleni stations and data transfer is conducted via MDS (microwave data systems) data radios back to a central, master station that runs a dual master and hot standby scada system for redundancy. The system includes 13 scada view nodes.
There are 216 stations in total, which span approximately 130 km from Midstream Estate in Centurion, past Nigel in the south, and from Etwatwa in the east to the Alberton/Germiston/Vosloorus area in the west. For manageability, the area is divided into three channels: north, south and east.
CAEs (chief area engineers) have permission to log staff on and off the SMS system in accordance with the staff roster, and to allow for vacation time and sick days. SSE accomplished this through the Adroit scripting agent.
CAEs can also log into the system to modify water level alarms and to control the automated SMS alarming during maintenance periods. The programme uses standard data logs to record all changes made to the system. There is also an online manual which SSE has devised for Ekurhuleni staff.
Network access is set up per each of the three channel regions on Internet Protocol. A Moxa n-Port switch located on the roof of the central polling station in Boksburg converts RS232 telemetry data to a virtual network on which each station has a standard IP address. By configuring the architecture in this way, SSE eliminated the need for licensing and view nodes. Data from the sites is live, time stamped by the OPC (OLE for process control) system and written directly to the scada.
"Data polling is extremely quick. On a bad day, I can poll data from all 216 sites in 45 seconds, and on a good day in around 20 seconds," says Andre Dethioux, installations manager for SSE.
Mouse-overs provide information such as the physical address of the site, the digipeater relay path of the data, percentage water levels for towers and reservoirs, as well as a percentage for battery volts at the telemetry outstations.
By running training exercises, the operators can see the benefits of properly managed pump rotation. Management can also see if there is a problem in the system and if water needs to be rerouted, pipes changed or areas warned of possible outages before they happen. The effects of water and pressure are also clearly visible on the trend screens, with greater fluctuations apparent at smaller towers that cover a wider area and requiring more management. Peak usage times are also clearly visible on the trend screens.
Seated in front of just two screens, one with the polled field data, and the other with the SMS logging screen, Dethioux says: "This is my Matrix, I can find all the information that I need on these two screens."
Alarming is done via SMS, and on-screen alarm conditions flash red on the overview screen. A log is kept of all SMSs. SMS logging and message logging is kept in an ASCII datascape for all Adroit scada alarms. The system analyses the protocol that the SMS goes out on, and keeps the message on the server until delivery can be complete. In this way SSE can monitor the time that operators log on to the cellular network, and when they receive the messages. This can be checked against realtime data of when the alarms were made inactive and the situation solved.
Personnel are logged on site using RF tags, which SSE has programmed to register with the scada. By going into the system or simply by using the mouse-over where a worker is indicated on-site will bring up the name of that person. ERWAT (East Rand Water Care Company) workers are also issued with RF tags for sewage site maintenance, so that Ekurhuleni can monitor the activities of their suppliers. The Adroit Data Extraction Utility provides a history of who has been on site, with times and dates.
Once swiped on site, the RF tags disarm the alarm system for a period of 30 minutes, eliminating human error should the operator forget to rearm the site upon departure. Swiping the RF tag during the two minute warning delay ensures the operator an additional 30 minutes on site, if needed. This functionality is run by the RTUs at the site in case the Adroit system goes down.
"The system is expandable. We simply add a scada tag and an input on an RTU and it is good to go," says Dethioux, who has customised the scada to Ekurhuleni's requirements. Recent additions have included actual meter readings, pressures and flows. He reports that as the CAEs become more familiar with the system and the information it can provide, they are requesting additional information and scope.
For more information contact Dave Wibberley, Adroit Technologies, +27 (0)11 658 8100, [email protected], www.adroit.co.za
| Tel: | +27 11 658 8100 |
| Fax: | +27 11 658 8101 |
| Email: | [email protected] |
| www: | www.adroit.co.za |
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