Despite the vast amount of steelwork in the plant, he finds that the TETRA signal penetrates it well. “With the first group that we rolled out the system to, I issued them with their radios and asked them to search whether they had coverage all over. Two or three days after, one guy phoned me and said, ‘We have found a place where there is no coverage’.”

Anton describes how he went out to view the location, which was in a reinforced, square concrete building with a reactor inside and a lot of metal supporting it. The man explained that if you crawled underneath and held your radio vertical, then there was no coverage. “I told him, ‘Are you really going to need coverage there?’ He said: ‘No – but you told us to go in search for places where there is no coverage!’”

And that, Anton adds, was at an early stage when only two of the plant’s three TETRA radio sites had been put into service.

Remote control

A further feature of the control room is a comprehensive remote status monitoring and control system, employing equipment developed by a local South African manufacturer, E-S-S. This presents graphical screen displays showing a wide range of parameters across the entire network, including critical readings of temperatures, voltages and currents. The monitoring system also supports fire alarms and intruder alarms for the radio sites, and detects electrical problems such as mains or battery failure, rectifier faults and blown fuses.

A green indication on the screen shows that everything is working correctly; but if there is yellow or orange, it indicates a minor warning. Anton can drill down to examine the actual measured values. In the event of an alert, the system automatically sends out a notification by SMS or TETRA SDS to call for help. Historical information is stored by the system too: the operator can pick a date off the on-screen calendar to travel back in time.

E-S-S’s intelligent technology keeps telemetry traffic on the network to a minimum by monitoring the health of the equipment at each site and reporting back to the centre only when something goes wrong. This avoids the need for continually polling every site.

Word of mouth

“I think what impressed me most in the project this far is not the ‘everything-went-well’ situation”, says Frik Smit, manager of the Specialized Services Group at Sasolburg, reviewing the TETRA experience. “We were at a stage when the system didn’t work. What was impressive, however, was the immediate response and action we received from Rohde & Schwarz.”

When the system was first started up, Anton explains, it was found that the two mirrored TETRA hubs were refusing to talk to each other across their E1 telecoms links. “In the test environment, when we put all the equipment in the same room, switches, base stations, connected with wires, it worked 100 per cent. But as soon as we moved the equipment to work over the microwave link, for some reason the E1 lines stopped working.”

Later it would turn out that the cause was a small difference in a voltage level between the two ends. But the team’s first action was to contact Rohde & Schwarz in Germany with their assessment of the situation, and they received an immediate response. “In no time they agreed to send a technical expert to South Africa”, Frik Smit continues. “The problem was located in a reasonably short period of time and sorted. In that entire situation, I commend Rohde & Schwarz for their responsiveness and taking responsibility of sorting out problems we encounter.

“We are very pleased that the system is fully functional, but the customer service we experienced from Rohde & Schwarz was quite remarkable.”

Now subscriber numbers at Sasolburg are on the increase as a series of new projects gets underway. The requirement is growth, and orders for more radios are rolling in. 

“People will not ask for something if they did not trust that it worked”, comments Christo. “Now that the system has been tried and tested and proven to be effective, there is confidence in it and the demand for it speaks for itself.”

“To me, the high demand is a classic example of a system selling itself”, adds Frik Smit. “It is just by word of mouth. People speak of its functionality which is different to the previous system, and in that way, it sells itself. People are looking for an improved alternative and this system offers world-class functionalities.

“What was fulfilling for us was that we never had to go back on our word to our clients. What we promised they would gain from the system is exactly what they got – and, to date, there have been no complaints from them regarding expectations that were not met.”

Taking the system’s pulse