Imagine you’re on vacation… when you receive a phone call. In the two weeks that you’ve been gone, a heat wave has enveloped your home town; it hasn’t rained in weeks.

The voice on the other end is frantic. Up until yesterday, everything was fine; today the irrigation systems on several clients’ properties aren’t working properly, and parts of them have shut down.

In the past, that may have caused you to scramble back home, or at the very least, call up repair crews, having them spend hours trying to diagnose the problem. But that was the past. Today, you just fire up your laptop, and with a few points and clicks of a mouse, not only do you figure out what’s wrong, but fix it from the pool side lounge chair in Costa Rica as you sip on a Pina Colada.

Welcome to the world of the central controller serving all the irrigation systems in your charge – a system that is accessible and adjustable from anywhere in the world.

While central controllers have been around for more than two decades, the advances in computer, digital, and communications technologies have changed what they can do and the way they operate. Gone for the most part are the electro-mechanical and the first few generations of solid state controllers. In their place are state-of-the-art digital devices designed to save the property owner and landscape contractor alike both time and money.

Since there are several irrigation controllers on the market, to avoid confusion, we should first define what we mean by a central controller. The central controller is the main controller where you can program your entire sites irrigation requirements. For the purposes of this article, it is a controller with the capability of being computer operated for all functions. Included in those functions are irrigation scheduling, automatic schedule adjustments, alarm processing, and reports providing historic and future performance.

Depending on the manufacturer, the computer that you use can be the engine driving the system, a partner working in conjunction with other components in the field, or basically the central communication device coordinating all the irrigation sites that you’re managing. Some systems are web-based; some are PC-based. Depending on your needs, they can also be quite elaborate in their ability to manage both the size and quantity of sites.

“In essence, central controllers give you the ability to manage multiple field controllers at one or more sites,” says Jeff Miller, of Toro Irrigation, Riverside, California.” Some companies use the Internet, some companies use a computer and add special software, and some companies have controllers which split the intelligence between the actual controllers in the field and the computer.”

Despite the different ways manufacturers utilize the computer, a key ingredient they all have in common is two-way communications between the field controllers (or satellites) and the computer operating the system. Without it, the computer is nothing more than a fancy timer. “While there are many different facets of central control,” says John Torosian of Rain Master, Simi Valley, California, “two-way communication is an absolute requirement.”

As the personal computer became less expensive and widely available, companies began integrating field satellites and controlling them from one point. The ramifications were huge. It gave individuals the ability to manage field controllers spread over large contiguous sites such as golf courses and parks, to disparate sites throughout cities and municipalities. And the flexibility that provided, allowed smaller crews to perform a task it once took an army to administer.

Photo Courtesy: Rain Bird

“In terms of monitoring operations in the field,” says Mike Rivers of Rain Bird, Tucson, Arizona, “you can take inputs from an array of sensors. You can isolate leaks; then you can notify the user of leaks. If you’re a school district with multiple sites, and a small maintenance crew, you can deploy that crew in an efficient way to deal with issues based on the alarms that the central controller will give you. “

That ability to monitor every aspect of an irrigation system’s operation is what sets central controllers apart from most stand-alone controllers. “The communications are what makes or breaks central control systems,” says Dave Shoup of Hunter Industries, San Marcos, California. “Most people in the irrigation industry think of central systems as irrigation systems that communicate. But the people who’ve been around them for any length of time know that they are communications systems that are designed to irrigate.”

How manufacturers achieve that two-way communication differs, along with the various ways they employ computers in the communication process. But the desired end result is the same -- the management of the information coming in from the field: from alerting a manager about site condition and potential problems; to automatic scheduling adjustments.

There are at least three approaches to managing central controllers: the PC-based system; the web-based system, and the internet-friendly, field controller-based system. Before trying to figure out which system would best fit your particular needs, let’s first explore how each of them works.

A PC-based central control system requires a computer that’s dedicated to the needs of the irrigation system. They are usually installed on larger commercial sites and municipalities. By using a variety of technologies that include cellular, UHF radio, telephone lines and the Ethernet, the computer communicates directly to the field controllers.

The field controllers are managed by that central computer, although some manufacturers have controllers with intelligent management systems that provide additional main line protection by detecting faults from broken wires, shorted wires, control-flow capabilities and no-flow alarm conditions.

“Those are built into the system,” says Torosian, “so that even if there was no central computer available, you’d be able to access those management features from the controllers in the field.”

Web-based central control systems offer many of the features of their PC-based counterparts, but do not need a computer dedicated to irrigation. Internet access is required to operate the system, but the computer doing most of the work is not yours, it’s housed by the company offering the service.

“Each one of the controllers that you have on-site is accessible via a password-protected, secure website,” says Chris Manchuck, of HydroPoint Data Systems, Petaluma, California. “You would just log onto the website, and see all the controllers you’re managing. You could then program those controllers, view what’s happening with them, along with getting alerts and messages sent from the controllers to the website.”

“Instead of being tied to your desk PC,” says Drew Ferraro of Signature Control Systems, Irvine, California, “you can be sitting in Starbucks, on your laptop, actually turning on your controllers, that could be 12 states away.”

Only a few companies currently offer a web-based system, but its affordability makes it a viable alternative to landscape and maintenance contractors wanting to centralize control of the irrigation systems they service, but have been shut out in the past by sticker shock.

“The market wanted a central control system that was more affordable,” says Torosian. “One that would allow maintenance companies the ability to centrally manage irrigation systems efficiently, automatically, at a cost that was accessible for their needs.”

One of the newest approaches to central control offers internet access to an irrigation system, yet is neither web- nor PC-based. Using the field controllers as the brains of the operation, these systems allow the remote capabilities the other systems offer, without the need for a dedicated PC or a web-hosted controller.

“We’re kind of a third niche,” says Larry Sarver of Tucor Inc. in Wexford, Pennsylvania. “We don’t require a dedicated computer to manage our controllers. We don’t require you to dial into a web-based server that’s hosted by the manufacturer. We give you software to communicate to the controllers using the internet, or even phone lines. But all the data bases are all stored on-site in the controller.”

“In the past,” Sarver continues, “it was the high-end, high-profile manufactures that had these big systems designed for universities and municipalities, who had a full-time operator to manage them. Today, systems like ours and others that are coming out, allow the guy who does irrigation for a living, to take his installed customer base and offer a whole new service, which is managing and monitoring irrigation as a service.”

According to David Byma of Calsense in Carlsbad, California, putting a high end processor in the field controller allows it to make water management decisions even when the computer is off-line. “What we’ve done is put a lot of power into the field controller itself. You can almost visualize our irrigation controller as a computer. The controller is not dependent on an outside computer to make decisions for flow problems. It makes flow management decisions on its own.”

Photo Courtesy: Rain Master

Managing an irrigation system from a remote location may be what first motivates a landscape contractor to install a central control system, but it’s their ability to make a myriad of decisions independently that makes them more and more essential as water purveyors require better water management practice and water conservation becomes more crucial.

“In some ways,” says Shoup, “alarm management is the bigger payback of central control; the benefit of knowing what went on in the field without having to drive over to each location and look around.”

Because of the varying abilities of central controllers to perform tasks such hydraulic management and reporting capabilities, there’s really no one-size-fits all system. Before purchasing any system, you should consider several factors.

“In almost every case where these systems are purchased,” says Rivers, “there’s a financial justification that has to be done, in terms of payback of the system: either in labor savings or water cost savings. So the size of the site is something to consider.”

“Also the remoteness of the site; whether it is nearby, or far away and difficult to get to and manage. It’s typically when the site is very large, or has remote segments to it, that central control becomes very appealing; and also when the water savings are potentially very large.”

“Whether it’s our system or anybody else’s,” says Torosian, “it’s best to do your homework before selecting a central control investment. Choose a system that fills your needs, not one that somebody is telling you what you need.”

In today’s ever-evolving world, it’s certainly difficult to predict the future of technology. Just as unpredictable, are weather patterns and climactic changes. But no matter which controller you choose, adding central control to an irrigation system will make managing and maintaining that system predictably easier. It will save you travel time and labor costs, while saving your clients water and money. And that’s an outlook with a future so bright, that you may have to wear shades.