Advances in Water Treatment and Enviromental Management

96 WATER TREATMENTVarious telemetry solutions were drafted using models derived from withinthe UK water industry and elsewhere. The specification of outstationfunctionality and input/output size was determined using referencedatabase data of site types and likely signal provision and performingstatistical analysis to extract PMCS specific information. This along withother statistically derived data was then subjected to pilot site audits totest the analysis.The computers and workstations components of the various designs wereagain drafted from computer stored records of manufacturers’ quoted andrecently tendered prices. An important element in all designs was theidentification of the need for software development. Clearly some softwaremodification and development may have been required, but the impact ofsuch development was to be clearly defined and the impact onimplementation determined.Communications are a key component of all the technical solutionsconsidered. Based on the needs analysis a range of potential solutions wasconsidered.Consistent with most UK schemes, the use of the British Telecom PrivateSwitched Telephone Network, already establshed in 90% of outstation totelemetry computer applications was to be the preferred choice. For theremaining communication lines to sites private wire and radiocommunication were to be specified. The high level communications wereto be based on the manufacturer independent protocols supportedthroughout Europe which offered high resilience and ‘open’interconnection.The solution options available for site investments required considerationof existing asset life and reliability, the adequacy and maintenance of existingassets and the suitability of measurement equipment to deliver theoperational need.Generally the PMCS project did not attempt to replace existing compatibleinstruments, provide local automation on works or provide qualitymonitoring other than by interfacing to instruments which were currentand necessary.A major factor associated with site related solutions was the recognitionthat sites would need to continue to remain operational during theinstallation period and that existing instrumentation and telemetry wouldremain in service until the new facility had been proven operationally.