Raj,

"Many of the large scale SCADA applications are run in Windows NT technology these days"

Just returned from a site which uses the latest yyyyy from xxxxxx for a dual redundant control system under NT4. ( Why tell the brand name and start a flame war ?)

But I always wonder why these SCADA systems with all the processor horsepower behind them struggle to update a screen image of a field event in under 1 second ( that is 1000 milliseconds !) And the guys boasted of a "fast interrupt input " and you know what the latency of this channel is ? 35 milliseconds and I am not joking.

Migrating back and forth between these SCADA systems and our beloved MCUs is full of contrasts. Microsecond loops are child's play for my humble 89c51RD2 with a 6Mhz crystal.

Try doing that with a top notch SCADA package.

Raghu