SCADA systems – and the soft logic question

`Soft logic misses the point, is essentially hype and potentially dangerous.’ That was the message at last month’s `SCADA towards 2001′ symposium, sponsored by C&I and organised by the Gatton section of the InstMC. Alan Williams, of Mitsubishi, dealt decisively with the question: `Will the PLC be killed by soft logic controllers?’ `What can soft […]

`Soft logic misses the point, is essentially hype and potentially dangerous.’ That was the message at last month’s `SCADA towards 2001′ symposium, sponsored by C&I and organised by the Gatton section of the InstMC.

Alan Williams, of Mitsubishi, dealt decisively with the question: `Will the PLC be killed by soft logic controllers?’ `What can soft logic replace?’, he asked. `Not the micro PLCs; not big systems – only mid range PLC processors. Then you’ve got to question reliability of the hardware, software and operating systems, which in PLCs have been honed for industry strength.

`What about the Windows blue screen of death?’, he asked. `They tell you control is still running, but it’s a bit “do you feel lucky?” – because you haven’t got a clue.’

He also pointed out MTBF and MTTR issues, fault tolerance and the dangers of exposing raw PC hardware and software. However, Williams confirmed to C&I that his condemnatory approach was in response to the many pro-soft logic pieces carried in the media.

Bob Butts, of Boward and the symposium chair, looked at the `largely failed generalised MES market’. He said that reasons for failure included plants’ different states of automation and goals.

`Bespoke software is needed to integrate disparate plant floor and business systems – not standard packages’, he said. `The Microsoft plug-and-play jack-plug, OPC, is something for the future, with data connectivity for all, but it’s not the be all and end all.’

He said that SCADA package costs would fall – as would the number of companies offering them. He also expected `techno-raiders’ to lift ideas, such as MMI for Windows or Java-based SCADA. `One of the questions to be faced by end users is who holds ownership of their systems – the integrator, SCADA vendor or PLC-supplier? All offer services.’

The symposium also dealt with: SCADA and the Internet, ERP systems; the Year 2000 problem; and Microsoft’s own strategy for the future of manufacturing.

Proceedings are available from the Gatton section at £35. Tel David Southey on 01372 726140.