9727
Previous Page: SCADA: DPS Telecom Remote Site Survey
PDFDownload White Paper

SCADA Red Industrial Light

The World's Simplest SCADA System

The simplest possible SCADA system would be a single circuit that notifies you of one event. Imagine a fabrication machine that produces widgets. Every time the machine finishes a widget, it activates a switch. The switch turns on a light on a panel, which tells a human operator that a widget has been completed.

Obviously, a real SCADA system does more than this simple model. But the principle is the same. A full-scale SCADA system just monitors more stuff over greater distances.
Let's look at what is added to our simple model to create a full-scale SCADA system:

Data Acquisition

First, the systems you need to monitor are much more complex than just one machine with one output. So a real-life SCADA system needs to monitor hundreds or thousands of sensors. Some sensors measure inputs into the system (for example, water flowing into a reservoir), and some sensors measure outputs (like valve pressure as water is released from the reservoir).
Some of those sensors measure simple events that can be detected by a straightforward on/off switch, called a discrete input (or digital input). For example, in our simple model of the widget fabricator, the switch that turns on the light would be a discrete input. In real life, discrete inputs are used to measure simple states, like whether equipment is on or off, or tripwire alarms, like a power failure at a critical facility.

Some sensors measure more complex situations where exact measurement is important. These are analog sensors, which can detect continuous changes in a voltage or current input. Analog sensors are used to track fluid levels in tanks, voltage levels in batteries, temperature and other factors that can be measured in a continuous range of input.

For most analog factors, there is a normal range defined by a bottom and top level. For example, you may want the temperature in a server room to stay between 60 and 85 degrees Fahrenheit. If the temperature goes above or below this range, it will trigger a threshold alarm. In more advanced systems, there are four threshold alarms for analog sensors, defining Major Under, Minor Under, Minor Over and Major Over alarms.

 

Next Page: SCADA: This RTU (Remote Telemetry Unit) Grows with Your Network
PDFDownload White Paper

Get a Custom Application Diagram of Your Perfect-Fit Monitoring System

There is no other network on the planet that is exactly like yours. For that reason, you need to build a monitoring system that's the right fit for you.

"Buying more than you need" and "buying less than you need" are real risks. You also have to think about training, tech support, and upgrade availability.

Send me a quick online message about what you're trying to accomplish. I'll work with you to build a custom PDF application diagram that's a perfect fit for your network.


Make an Informed Decision


Your network isn't off-the-shelf.

Your monitoring system shouldn't be, either.

Customized monitoring application drawing

We'll walk you through this with a customized monitoring diagram.

Just tell us what you're trying to accomplish with remote monitoring.

Get a Custom Diagram