Change Detection in a Power Plant Monitoring Application

This document is part of a comprehensive tutorial on industrial Digital I/O and Counter/Timer hardware. Learn about National Instruments product offerings for digital and timing I/O, the Industrial Feature Set including watchdog timers and isolation, complementary devices like relays, solenoids and encoders, concepts like sinking and sourcing, and see how these devices can be used in your industrial application.

For more information return to the Complete Industrial Digital I/O and Timing Tutorial.

Change Detection in a Power Plant Monitoring Application

In August of 2003, several northeastern American cities were hit by an electrical blackout that left millions of people without power. During the investigation that followed, officials tried to determine the cause of the blackout. In an event such as this, the ability to view the state of the system as it was minutes, hours, or even days before the event is extremely valuable.

Since a system can change sporadically, it needs to be monitored at all times. On the other hand, constantly measuring the system at a set interval can result in enormous amounts of data, much of which is repetitive and irrelevant.

Change detection provides the best of both worlds by removing the repetitive data while still recording important system events. Using change detection, data is only captured when a rising or falling edge is detected on specified inputs. For example, any time a relay opens or closes, the states of all relays will be captured and saved in case they are needed at a later time.

Recommended Products that Feature Change Detection

NI 6514
NI 6515
NI 6528

Learn More About Change Detection

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