In a recent feature on how local companies were contributing to developments in the I&C industry, one critical aspect, namely telemetry, was not addressed. There are at least three South African companies that are innovators in this field, these being Omniflex, the Spero Group (Spero), and Specialist System Engineering (SSE). Omniflex was established as long ago as 1965 (originally operating as Conlog) while the Spero Group was started in 1988 with a dedicated telemetry division, Sperolons, being created during 1997.
The company SSE has some 15 years experience in the telemetry market. While Spero and SSE are focused specifically on the needs of the local southern African market, the products from Omniflex have been sold to companies operating in five continents. Specific Spero products have, however, created interest in the mining industry of other countries such as Australia.
Spero Group
In terms of telemetry, the focus of Spero lies in the mining industry and it was with this market in view that the company developed its SL2000 harsh environment telemetry system. This focus was to some extent driven by the fact that as an engineering company Spero has a background of developing products and systems for the even stricter military specifications.
The SL2000 was originally developed for fire detection but its versatility was soon recognised and further developments have seen it being used in a host of other applications including environmental and utility monitoring, process control, conveyor belt control and monitoring, safety and rescue as well as man and vehicle tracking. Spero itself also offers a wide range of environmental sensors specifically designed for harsh underground conditions and these are used to complement the network. The SL2000 has found a particular niche in the gold mining industry with many major South African mines (Target, Great Noligwa, Moab, Kloof, etc) having standardised on the product. A more recent marketing initiative by Spero will see the local coal and platinum mining industry also being addressed, while it can be expected that the international mining groups will employ the system in their overseas operations.
SL2000 is based on the Lonworks protocol, acceptance of which is growing rapidly in the mining industry. Operation is possible using a number of different media types, including conventional twisted pair cable, optical fibre, power cable, Ethernet and radio. The media used depends on the specific application and can be mixed within the network. The system effectively consists of a PC situated above ground that is connected to a network spanning the entire mining operations. The network usually consists of a communications backbone leading into the mine with services networks linking the backbone into all of the underground working areas. The service network can distribute DC power together with the communications signals to all the service points, a range of I/O devices being connected to the latter.
In the above-ground control room the software comprises a Lonworks Network Manager tool together with an appropriate scada system. The choice of scada to be used is the choice of the customer and SL2000 will support most of the common systems including Citect, In Touch, WINCC and Adroit. For South African users a major selling point is the fact that the system was locally developed and is fully supported by Spero's own engineers.
Specialist System Engineering
SSE also has the development of high-tech military and aerospace systems as a background and its market for telemetry includes many utility related remote applications such as water, electrical, irrigation, sewage, traffic control and gas distribution. Interesting applications include the remote monitoring of strategically placed rain gauges and river flow monitors that can provide timeous warning of flood situations downstream. At the other end of the scale their telemetry system can be used for building management with the monitoring and control of systems and devices such as airconditioners, electrical systems, elevators and security systems.
With some 15 years experience in telemetry the SSE-RTU-3 series of telemetry systems are packaged with features specific for local applications and often not found in imported competitive products. Besides being ahead in terms of technology the solutions offered by SSE are cost-effective and are fully supported within southern Africa.
With all the possibilities of local and remote communication and varying topologies, the SSE Tele-Control equipment can communicate over an extensive range and combination of mediums. These include private radio networks, fixed line public telephone, cellular through full comms or SMS, satellite, ISDN lines, optical fibre, RS485 or dedicated lines. A standard feature of the RTU is 'store and forward' and this enables any remote station to be used as a digital repeater for the transmission of data to other stations. With a focus on remote stations SSE has addressed the issues of lightning and surge protection and solar battery chargers can be incorporated. The overall design philosophy for remote stations rests on three fundamentals, these being immunity, reliability and autonomy, critical features in a country like South Africa.
The master stations operate using any scada package for the display of information, data capture, trending, alarming and control of remote stations. SSE has itself developed a number of protocol drivers for the most common scada packages but the OPC service protocol driver makes the system fully accessible to any software package with OLE or OPC client software.
A wide range of RTU modules and controllers are offered covering both digital and analog (4-20 mA) inputs and outputs. The RTU-3 CPU processor module, which forms the heart of the station, has an on-board 128 KB memory (expandable with external modules) and controls up to 12 I/O modules per RTU controller, the number of controllers being up to 16. The system has an on-board FFSK radio modem that can be connected to virtually any two-way radio system, while two RS232 ports connect to modems for the other communications media offered. Memory expansion modules offer up to 1 MB of memory and up to 12 of these can be added to the RTU. Memory storage is non-volatile with a 10-year backup of memory in the absence of power.
Omniflex
The last and longest established of the local telemetry companies is Omniflex which designs and manufactures products for the automation and control industry and besides telemetry systems its portfolio includes power supplies, alarm and event management, signal conditioning and monitoring and control systems. Through a worldwide partner network (partners exist in the USA, Europe, the Middle East, Far East and Africa) Omniflex specialises in providing solutions for industry. Although part of the original Conlog group the Conlog Industrial Products business was acquired by the present owners in 1997 and the name of the new company was changed to Omniflex. Omniflex owns all of the intellectual property rights for the industrial products previously sold under the Conlog brand and full technical and service support is provided for these products.
The company's focus is industrial control systems and in terms of telemetry its flagship product range is the Maxiflex telemetry and remote I/O system. At the core of the Omniflex solution is its CONET communications infrastructure which, when implemented on the Maxiflex platform range allows many communications standards to be blended into a unified plant-wide I/O and information system. CONET thus allows plant operators to integrate their legacy infrastructure into an optimised system that can be later further upgraded and developed. The CONET network can also fetch data over distances of 10 km on existing cables, making the integration of previously infeasible systems possible.
Maxiflex base stations are available in various sizes and allow up to 15 I/O modules to be connected to a CPU. The modules can be analog or digital. The digital I/O is available with capacities from 8 to 32 I/O and can cater for inputs from 10 to 30 V d.c. or from 30 to 60 V d.c. A special module is also available with the capability of withstanding voltages up to 200 V d.c. Analog modules offer 8 to 16 channels and for temperature measurement the mV or resistance input from RTDs and thermocouples can be converted by programmable modules directly to temperature.
In terms of telemetry the system will accept all standard transmission media including cable, twisted pairs, optical fibre, radio, GSM and coaxial cable. The Maxiflex event stream can be processed by any OPC client system (eg, scada) facilitating the use of any state-of-the-art database analysis and reporting tools. Data is 'time stamped at source' ensuring that chronologically correct data is collected over the entire distributed system
The Maxiflex Process Automation Suite is a fully modular system where the customer is encouraged to buy only what he needs now and to expand as the need and funding occurs. Maxiflex is endowed with the capability to implement hierarchical networks and for example it allows seamless routing from Ethernet to the CONET Fieldbus network.
Together these three companies along with a number of smaller players are able to address the telemetry needs of local industry, mining and infrastructural companies and their offerings should lead in future to greater export potential.
Dr Maurice McDowell, has many years' experience as a technical journalist, editor, business manager and research scientist. His third party analyses of world-class companies and processes, as well as his insight into industry and technology trends are well respected.
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