Programlanabilir Lojik Kontrolörler, Bristol Su İşletmesine bir telemetri çözümü sağlamaktadır

Su Endüstrisi, Omron Electronics’in önemli ilgi alanlarındandır; birçok yeni müşteriyle çalışmış ve geniş bir uygulama alanı yelpazesine yönelik çözümler için başarılı bir şekilde yeni ve yenilikçi ürünler geliştirilmiştir.

Solution for modern demands on water quality When Bristol Water looked to replace its telemetry outstations and plant control equipment, it looked beyond the traditional and the conventional in order to ensure it installed the best performance solution. Bringing new ideas to the water industry, Omron provided an outstation controller and telemetry solution built around programmable logic controllers.

The telemetry outstations operating at Bristol Water dated back to 1976. Although the central control system had been replaced a number of times to take advantage of the massive leaps in computing power over the years, the various outstations had been simply upgraded. Although operational, after 20 years they were becoming difficult to service.

Reckhouse had investigated the use of modern programmable logic controllers (PLCs) before in control of the process, and had found them to be both robust and reliable. So when Omron's water industry team offered a solution that would match and exceed Bristol Water's telemetry outstation needs, he was interested. Although traditional use for PLCs in the industry is for works automation, the specification for this new angle on control showed Omron's PLCs to be an improved solution not only for plant control, but also for providing the required telemetry functionality.

Having put the replacement of the outstations out to tender, and having received a number of proposals, a shortlist was drawn up, including Omron's PLC solution. The shortlisted control companies were each invited to install a test system. We had the test systems installed in the most environmentally demanding pumping outstation we could find, says Reckhouse. It was noisy - both electrically and in terms of vibration - hot, and overall thoroughly unpleasant. We put each system through weeks of rigorous testing, including getting all the people who were ever likely to use or access the system to try it out, get hands on experience, and give their assessments.

For simplicity and ease of serviceability, we developed one program that would provide both hub and satellite functionality, he continues. By doing this, we could load every PLC with the same program, and then simply tell the PLC what sort of controller it was.

The specification called for the use of some form of interactive operator feedback, and Omron's answer was an NT20S human machine interface (HMI) hooked up to one of the C200Ha's communication ports. The HMI was an important addition to the system for providing more information locally, and it proved to be an important differentiator for Omron, explains Bridgman. To give Bristol Water an idea of the power of the Omron HMI, we developed a number of demonstration screens, building in a lot of clever and useful functions, for alarm handling, analysing the I/O, trending, pump management, etc. As well as its functionality, though, a key advantage of the NT20S was its ability to operate reliably in a hostile environment - an outstation can see extremes of temperature from 0 up to 50 deg C.

With the trial system proving more than capable, Omron was awarded the contract to replace some 110 systems in the field. We were impressed with their in-house expertise, their in-house resources to develop and manage the project, and the quality and capabilities of their products, says Reckhouse. As well as a rugged and robust solution, the PLC system provided all the monitoring, diagnostics and statistical information we needed to perform the essential local trending. Equally important though are the system's inherent future proofing and expandability. With the PLC solution, we can add I/O as we go along, allowing us to incorporate the latest intelligent instruments as they come onto the market.