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Make Your PLC SCADA Call You With Voice Alerts

by Mac Smith

What is PLC SCADA?

A SCADA ( meaning Supervisory Control and Data Acquisition) system is a computer application that is used to monitor and control a plant or equipment at the supervisory level. The term "SCADA", as it is normally used, refers to a centralized monitor and control system of a complete network, or sometimes to an individual site that covers a long distance.

These supervisory systems can be used to manage any type of equipment. Companies use these systems to automate complex industrial processes, detect and correct problems, and measure trends over time. These processes include the water and waste control, energy, oil and gas refining, transportation, and telecommunications.

Most of the site control performed by a SCADA system is actually performed automatically by two types of devices, either RTUs and PLCs (Remote Terminal Units and Programmable Logic Controllers).

Data such as equipment status and meter readings are collected at the RTU and PLC level. If a system is designed to support alarm collection, that will also be done at this level.

If you chose to have a PLC SCADA network system at your organization, it's likely composed of many PLCs. PLCs, just like RTUs, can monitor all sorts of vital processes, like flow rates, temperatures, and manufacturing stages. They report real time data back to your central master station - also called Human Machine Interface (HMI SCADA) - giving you reasonable visibility of your actions.

The HMI serves as the master station that communicates the processed status and alarm information collected along the SCADA system to the human operator.

The HMI combines these pieces of data from the system into one place, saving operators from manually combining polled data from individual points.

Operators can view the system alarms and information through the HMI, and they can make educated decisions based on these readings. If a system is equipped with control functions, signals can be sent back to the RTUs to execute certain actions.

But how many times have you had a problem that went undetected until it caused major trouble? You can't be in front of a computer screen all the time, and you can't expect that your human staff will instantly recognize every important issue.

Voice alerts bring up-to-the-minute information about problems directly to the maintenance personnel who can immediately correct them. Voice messages go straight to your phone and require no login or checking in several times a day.

How to Get Voice Alerts from your PLCs

What you need is a device that connects to a handful of your most important PLCs. When one of these PLCs detected a vital problem, your new device would receive a contact closure and call your phone immediately. You'd receive a detailed voice message describing the problem. What's more, if you didn't respond to the message within a few minutes, an alternative operator could be contacted.

When you wire a NetGuardian Voice 16 into one or more of your PLCs, you'll be able to receive detailed voice alerts as described above. Your PLCs will still process data and send it to your HMI software. But, with a Voice 16 deployed, they'll send a supplemental voice alert to your phone. You can also connect the Voice 16 to non-PLC gear that outputs contact closures.

The NetGuardian Voice 16 G2 is a highly flexible RTU - it's a perfect fit for your medium-sized sites. The NetGuardian Voice 16 key feature is the voice dial-out alerts. If you want more than just email and SNMP notifications, the Voice 16 provides the perfect alert system for you.

You can set up voice alerts for as many or as few alarms as you need. Then you won't be overwhelmed with unimportant "nuisance" voice messages (nuisance alarms are minor, unimportant status alarms that require no corrective action).

If you have a large team managing your SCADA system, a PLC contact closure can trigger up to 8 sequential phone calls. The NetGuardian Voice 16 will keep escalating the call until someone "Presses 1" on their phone to acknowledge the alarm.

With escalating notifications, you'll have a list of people to be notified if an alarm is not acknowledged. If the first person on the list is unable to respond (because they're too busy, too distracted, or too deeply asleep) then the next person is notified (and so on down the list). With an escalation list, you'll never have to worry about a single person missing an alarm for hours at a time.

Redundant voice alerts also offer protection against communications network failure. Even if your PLCs can't talk with your master, the NetGuardian Voice 16 will still be able to dial out using its built-in modem.

PLC Voice Alerts Diagram

The NetGuardian Voice 16 allows you to receive voice alerts on your phone when important PLC SCADA devices detect threats to your actions. You can at the same time collect alarms from any other equipment that outputs contact closures.

The NetGuardian Voice 16 also uses a convenient web browser for configuration and monitoring. You don't have to waste precious time setting up confusing alarms in a needlessly complicated interface. The NetGuardian Voice 16's graphical web interface is designed with simplicity in mind. We designed it to be intuitive and easy-to-use, because managing your alarms shouldn't give you a headache.

If you have PLCs (or any other devices that output contact closures), you can use the NetGuardian Voice 16 to improve your responsiveness to alarms, improve your productivity, and improve your bottom line. Call DPS Today at 1-800-693-0351.

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