SCADA | Components for Data Collection and Management

You’ve just started your morning working from home. You have your coffee, start up your computer, check emails, and get motivated for the day. Then suddenly, disaster strikes. The power goes off to EVERYTHING! Your laptop’s low battery light begins to blink, your network is down, and that important meeting is looming on the horizon. If the power returns quickly, no problem, right? But, what if it doesn’t? Are you rushing to pack your things and find the closest coffee shop?

Power Outage Work Disaster

Most people don’t think about electricity until a problem arises. We rarely think about what goes on behind the scenes to fix it. The above scenario is from the electricity customer perspective. But, what about the people who address these events? Every time these events happen, they carry the weighted responsibility of being the ones who need to solve the problem. No doubt, they would be thrilled with a swift and easy fix. But, that isn’t always the case. So, how do they do it?

What is SCADA?

SCADA stand for Supervisory Control and Data Acquisition. Sounds a bit intense, right? Don’t be scared. It’s not as intimidating as it sounds.

SCADA Systems

A SCADA system is a computer-based instrument that gathers and analyzes real-time data to monitor and control equipment that handles time-sensitive and critical materials. So how does SCADA relate to your morning power meltdown? 

SCADA Equipment Needed to Fix Outages

SCADA systems need the event’s information to perform an analysis, develop and apply a solution. These systems obtain data in multiple forms ( discrete and compiled) to do just that. One of the best ways to analyze an event is to have a sequence of events recorded in the system. It supplies an opportunity at a comprehensive diagnostic tool.

For example, APT has worked with SEL meters and protection devices that have this capability included. The SEL 387, 2411, 751, 351, and 587z all offer sequence of events or timestamped metric capture. The data can be accessed at the system head end by a concentrator like the SEL 3530 RTAC (Real-Time Automation Controller). The RTAC provides remote access to both logs and diagnostics of the downstream devices via the Web interface or OBDC (Open Database Connectivity).  


The RTAC will require the setup of the downstream devices identified through the editor. The device can be any SEL product offering, including relays or automation controllers (mentioned above). Moreover, any other third-party devices will need to speak Modicon at a minimum and have a driver created.

Configured devices appear in the device tree of the RTAC unit. As a result, this allows the reports to be accessible to the RTAC.

Configured SCADA RTAC configured Devices

Finally, using the Web interface requiring the IP address of the RTAC and credentials, we will have a selection of reports. To find what we need, we have to filter the list for the sequence of events (SOE) (shown below). 

Selection of Reports by SCADA

How to use the Sequence of Events Reports?

Now that we have the data we need, an analysis of the event can occur. As a result, we can begin reconstructing what went wrong and when. Moreover, this also highlights a crucial part of the system not yet discussed. If the system isn’t solely SEL equipment and it uses another SER externally, it will be pointless if there is no timestamp. 

A timestamp allows us to see the order in which things occurred. Without it, we would be lost in understanding the recordings of the SER. So, as part of the system, a crucial requirement is a Satellite or GPS clock. For example, in our sample SEL system above, we relied on an SEL-2407 to give us the temporal accuracy required. 

APT Suggested Best Practices

If you have a SCADA system with an application required for a sequence of events recording, be sure to have:

  • A data concentrator
  • Relay or automation controller
  • A clock (most importantly) 

In short, this will almost guarantee that events record correctly on a path to a solution. Looking for more information? Contact an APT professional today to determine your facility’s SCADA needs.

Donald Flowers II. APT Field Service Engineer