Industrial SCADA alarms at the speed of 4G LTE: How cellular killed the radio star
The cell phone vibrates on the bedside table at 2 A.M. and the maintenance supervisor of the gas utility fumbles for the snooze button. It’s happened so much over the years that it’s not the exception, it’s simply expected-the late night alarm on one of the utility’s many lines in the dead of winter. As his tired eyes adjust to the bright screen, he finally reads the text from his SCADA (Supervisory Control and Data Acquisition) system’s alarm:
"Low flow at line 53."
"53, again!" He suppressed the outburst, not wanting to wake the rest of the house with his frustration. Besides the fact that line 53 is a 30-minute drive from his house, the temperature outside smashed the all-time lows for the past 100 years.
A slew of thoughts flew through his mind:
- Did the alarm just happen or did it take almost two hours to register?
- How many other sites are waiting to trip once I get done with this one?
- I really wish I could check the sites in real time.
- I want to be able to plan my site visits based on alarm priority.
The greater tragedy here, than simply being woken up in the middle of the night, is that the same technology that wakes the supervisor also has the ability to offer more information but is not fully being utilized by his utility district. In the last few years so much has changed in cellular communication in comparison to legacy communication options, such as radio and telephone, that merit taking a serious look cellular options.
The major issue, outside of a well-rested maintenance team, is the lack of efficiency from outdated technology. For example, back in the day, accessing the internet via a dial-up modem created many breakthroughs, but try using a dial-up connection today and watch your patience ebb into frustration faster than a riptide at the beach! The catalyst to frustration comes when you know something should or could perform quicker than it actually does.
What cellular has done to the telemetry market is what broadband has done to the dial-up connection. The speed of data provided by the cellular network is no longer cost prohibitive. Normal costs for telephone lines to transmit data from remote locations can run $50-$65 per line.
Although radio doesn’t typically have monthly usage fees, there are tremendous costs in the installation and maintenance of the system that should be considered. Installation costs can be extensive if an expansion requires the addition of repeater tower and radio. Tower costs alone can range from the mid $10,000’s to $100,000. Another concern is dealing with seasonal foliage, which can block line-of-site a few years after the installation of the system.
Cellular data plans can vary, but average about $20 per month with data usage plans that fit a majority of industrial needs.
Benefits of Cellular Modems Recap:
- Line of sight over time can change due to tree growth and seasonal foliage. This can greatly affect radio signal, but does not affect cellular transmission.
- Sites with radios that require a repeater tower site can be expensive. Repeater tower cost (tower, installation, site survey, and land cost) with another repeater radio can cost $15K-$100K.
- Cost for a cellular system vs. radio hardware is minimal per RTU. With an average cellular data plan per site of $20/month, the breakeven point – or ROI – (sites without a repeater) is 30 months. This monthly service plan needs to remain the same or less.
- Cellular systems require much less engineering and start up and testing time to establish a network and communication.
Cellular Modems – Data Collecting, Monitoring, and Controlling:
- Using cellular RTUs, support can go live on a remote site without interrupting the data being sent from other remote sites to a main site. Cellular allows remote access into to any site with a static IP for troubleshooting program modification. This saves travel time and cost.
- Remote site data and historical information is often compromised by the slow updates of a radio network if the system is not designed properly. Often the work around is to go to the site to download the info. Cellular sites can update in seconds to provide much better trending and data analysis in real time.
- Radio signals are much more prone to interference from other radio systems.
- Smartphones and Tablets (and soon possibly Smartwatches!) can access RTU’s via cellular with the right permissions.
There is something to be said about the companies and utilities that use time-tested practices and resist the urge to jump at every technological innovation in the marketplace. However, there comes a point of diminishing returns in either direction where an industrial organization either refuses every innovation or purchases each new technological leap. The key is finding the right balance in your particular industrial field that will lead to efficiency and set the stage for scaling improvements as your data communication needs develop.
Fortunately for utility and industry in general, cellular communication is not necessarily the new kid on the block. It has been around for decades, but the improved cellular infrastructure by national providers have made it more affordable to use cellular for remote site monitoring and control. The end-user gets the best of both worlds by incorporating a time-proven technology at relatively low costs, compared to the alternate methods of radio and telephone.
Several questions can help define the balance:
- How much time could be saved by your maintenance team using an updated SCADA system that incorporates cellular modems? By receiving real-time data, your team can prioritize their routes and respond to emergencies faster.
- What do peaks and valleys look like in your process? Cellular data can provide a more robust picture of your trends by providing more data in shorter intervals than radio or telephone. By capturing the data and using reporting features, you can make more informative decisions about your infrastructure’s needs.
- If updates and alarms are sent every hour or two, how much money could a single leak or stoppage cost your operations in that time?
- If you have more remote sites to add, would it be more valuable to your organization to consider adding these sites via cellular telemetry to make future expansion a lot more affordable and accessible?
There is more at stake for the utility or industry that uses outdated technology than the occurrence of late-night emergencies. Time wasted during poorly routed service calls, money lost from shutdowns or leaks that go undetected longer than necessary, high installation and maintenance costs of operating with antiquated systems, and significant data loss from using slower modes of communication can impact all stakeholders in the system.
By updating a SCADA system to a current platform with cellular capability, an industrial organization can lower operation costs, improve system diagnostics, and reduce system downtime in ways that benefit everyone from the board room to the end users.
Brendan Quigley graduated from Millsaps College in 2003 and joined Cross Company Integrated Systems Group – in early 2012 as an inside sales representative.
Cross Company Integrated Systems Group is a CSIA member as of 3/5/2015