Skip to content
WelcoYour alerts, by text.

What is SCADA and how does it send alarms?

SCADA (supervisory control and data acquisition) is the software that runs and watches a plant from a central screen. It collects readings from pumps, tanks and valves and raises an alarm when something goes wrong. Getting that alarm to a person after hours, often an operator miles from the plant, is the hard part.

Start free trialBook a demo

7-day free trial, 15 message creditsCard required for verificationNo charge for 7 daysEmail reminder before billing

Published:

Glossary

SCADA

In plain English, with what it means for alert texts.

Illustration of SCADA.

What a SCADA system is made of

Most SCADA setups have four parts, even in a small town water system on the Prairies.

  • Field devices at each site, such as sensors and PLCs, the small computers that run pumps and valves.
  • A link back to the control room, often radio, cellular or fiber.
  • The HMI (human-machine interface), the screens operators use to watch the plant and clear alarms.
  • A process historian that keeps readings over time.

How SCADA alarms reach people

Inside the plant, alarms flash on the HMI. When nobody is in the control room, the alarm has to travel to a phone. Small Canadian municipal utilities often run unstaffed at night, so this matters every shift.

Older sites used phone dialers or carrier email-to-text addresses, such as Bell's retired one, for this. Most SCADA packages can also send an alarm email, and that email is all Welco needs.

A SCADA alarm as the operator sees it

A clearwell level alarm from a municipal treatment plant, sent to the operator on call that night.

  • Clearwell high high level: Welco: [Clearwell] Tank level HIGH HIGH at 3:44 AM. Inlet valve open. Reply STOP to opt out.

A phone showing these alert texts: Clearwell high high level, "Welco: [Clearwell] Tank level HIGH HIGH at 3:44 AM. Inlet valve open. Reply STOP to opt out."

SCADA vs HMI vs DCS

The HMI is the screen. SCADA is the whole system behind it, spread over many remote sites. A DCS (distributed control system) runs one large plant, such as a refinery, with tight control loops.

For alarm texts the difference rarely matters. If the system can send an email, it can text a phone. Other plant terms sit in this plain-English glossary.

What SCADA means for your alarm texts

Welco works with GE iFIX alarm texts, Ignition and WIN-911 today. Point the alarm email at your Welco address and the text goes to the operator on call.

A tripped breaker can set off dozens of SCADA alarms at once. Plan for that with the guide to preventing alarm floods. For setup by system, start at SCADA alarm notification.

Frequently asked questions

Is SCADA hardware or software?

Both, in practice. SCADA is mainly software, but it relies on field hardware such as PLCs, RTUs and radios. When people say the SCADA, they usually mean the server and screens in the control room.

What does an RTU do in a SCADA system?

An RTU (remote terminal unit) sits at a remote site and reports its readings back to SCADA. It is close kin to a PLC but built for distant sites and slow links.

Does Welco need a connection into our utility's SCADA network?

No. Welco only receives the alarm email your SCADA already sends out. Nothing reaches back into the control network, and no software is installed on it.

Can an operator answer a SCADA alarm text?

They can reply, and the reply comes back by email. A reply does not acknowledge the alarm inside SCADA, so the operator still clears it there.

Get your SCADA alarms onto the night phone

Keep the SCADA system you have and add one email address.

Text me my SCADA alarmsBook a demo

7-day free trial, 15 message creditsCard required for verificationNo charge for 7 daysEmail reminder before billing