Customer Solutions

A New HMI/SCADA System for Dane County's Warning Sirens

Author(s):

David Janda, Evans Communications

Industry:

Government/Defense

Product:

Lookout

The Challenge:

Updating an existing siren control system to improve reliability and provide expanded control and data acquisition capabilities.

The Solution:

Creating a PC-based HMI/SCADA system using Lookout for a reliable siren system.

Introduction
Dane County, located in southern Wisconsin, is home to approximately 420,000 people, with about 200,000 residing in the City of Madison. Dane County, like most areas of the country, is at moderate risk to a variety of natural and man-made hazards. The most common of these is the threat of severe weather, including tornadoes. In response to this threat, Dane County owns and operates a siren system comprised of 99 sirens as the outdoor component of an all-hazards emergency warning system. The reliability of this system is of utmost importance to avoid loss of life caused by an impending threat.

Updating the System
The project consisted of updating the existing siren control system to solve historical, ongoing problems with reliability. The existing legacy system, entirely proprietary, only operated and monitored outdoor warning sirens. The system was of little help with maintenance as components failed or became obsolete. The system operated through a two-way radio system, with proprietary DOS-based software and controllers constituting the central control system and proprietary remote terminal units (RTUs) and programmable logic controllers (PLCs) as the control components at each siren site in the field.

Creating a Nonproprietary System
To address some long-standing problems with the siren system, we designed the new system to meet certain basic criteria. First and foremost, we planned for the system to be as nonproprietary as possible. In addition, because we had already begun a project to update the control components at each of the siren sites using Zetron RTUs, GE Fanuc PLCs, and Motorola mobile radios, we needed an HMI compatible with these components. The Lookout system performs the following basic functions:
• Obtain data from the remote sites and activate the sirens through a two-way radio system
• Provide the user with a simple graphical interface displaying color maps of the county siren system
• Activate an individual siren, all sirens within a designated zone, or all sirens in the system
• Acquire data and record the operational status of the each siren
• Provide functional redundancy in all aspects of the central control system

Designing for System Reliability
The National Instruments Lookout application, developed by Vista Technology, Inc., exceeded our expectations for the siren control system. They designed every aspect of the HMI system with reliability in mind, making all aspects of the system functionally redundant. The Lookout system runs on two networked Pentium PCs. The primary server resides in the Dane County Emergency Management Office, and the secondary PC, in the county 911 center. The 911 center also houses a third PC that provides the operator interface. The primary and the secondary PCs can both control the sirens through separate connections to the radio system. The secondary PC in the 911 center performs like any other network machine, with the exception that it monitors the primary PC for a failure. In the event of failure, control of the sirens automatically switches from the primary to the secondary PC, transparent to the user.
With Lookout, the operation of the siren control is simple and intuitive. Vista Technology configured the HMI system to provide an overview screen that shows a map of the county. By pointing and clicking, the user can navigate from the overview screen to more detailed zone map screens that show the location of each siren. Siren activation also takes place by the click of the mouse. All commands require an action verification before Lookout initiates the command.

Efficient Data Logging and Alarms
Another important aspect of the Lookout system is data logging and alarm generation. The system automatically logs the results of every command issued, which creates a permanent record of all siren activation and test results. In addition, the system also monitors the status of AC and DC power at each of the siren sites. A power or radio communication failure automatically generates an alarm that the system supervisor must acknowledge. A new feature is the ability to perform a quiet test, so you can test the overall functioning of the siren without actually sounding the unit and log the results of all quiet tests, as well. This data-logging and alarm feature was not functional in the previous control system.
We relied heavily on citizen reports of siren failure and the results of radio polling to determine the operational status of the system. With Lookout data-logging and alarm capabilities, we can track maintenance needs of the sirens much more effectively than we could with our legacy system, resulting in lowered annual maintenance costs and increased overall system reliability.

Flexibility with Lookout
The flexibility and ease of Lookout was invaluable to the success of the project. The ability to communicate with the existing hardware was critical, as was the ease of testing in the development phase of the project, and National Instruments Lookout met these requirements. We are very pleased with all aspects of the project and the final product. In the end, it was truly satisfying to see our general ideas of a new siren HMI system realized.

For more information, contact:

 David Janda

Dane County Emergency Management

Public Safety Building, Room 2107

115 West Doty

Madison, WI 53703

Tel: (608) 266-5950

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