Pocket PCs for Remote Facility Monitoring

Remote monitoring basics

Many organizations are responsible for the maintenance of remote facilities ­ facilities that do not normally have staff present. Examples include equipment as diverse as navigational transmitters on mountaintops and channel buoys at sea. These facilities often have a variety of equipment installed, and much of it has monitoring capability built in.

As a provider of remote monitoring services, we have constructed a number of custom monitoring interfaces over the years. In the most common scenario, we provide a translator box that converts signals generated by the equipment (usually through an RS-232 serial interface) into a standardized proprietary dataset. This data is then transmitted to a monitoring center. The translator box also serves as a threshold monitor, sending signals to the data center only if preset threshold values are violated. We refer to these signals as alarms. When an alarm is received by the data center, it is interpreted as to level of severity and the appropriate action is taken. For example, the data center might receive a warning that a piece of equipment is failing and then send someone out to replace it.

Going into orbit

Traditionally, remote monitoring has been provided through dedicated dialup lines. But that changed with the advent of low-earth orbit (LEO) satellites. A LEO constellation provides us the ability to transmit alarm data from a remote facility to our data center at an affordable rate, opening the possibility of monitoring facilities that were out of the question using dialup lines.

Under this scenario, alarms are transmitted through the satellite constellation using a proprietary encryption scheme, eliminating the need for challenge-and-response verification.

Providing a Web interface

Once the alarm data is received in the data center, it feeds into a real-time monitoring application that issues auditory and visual feedback whenever an alarm status changes. Our next challenge was to provide the same information to highly-mobile managers in a way that would allow them to review the data, but not be responsible for immediate response. This seemed like a perfect case for implementation of a Web interface.

As alarm data is received, we now route it to a database as well as to the real-time monitoring application. A Web interface created with Allaire's ColdFusion provides a "green board" display that lets a manager review the status of remote facilities from any browser-equipped computer (see Screen 1).

Screen 1: We created the LRMS Web Interface to let mobile managers review the status of remote facilities from any browser-equipped computer, including the Pocket PC (shown here).

If all is well, each facility's cell in the display is green. If an alarm condition exists, the facility's cell color reflects the severity of the alarm. If multiple alarm conditions exist for a facility, the color of greatest severity takes precedence. The manager can click on the facility's name to see a list of the equipment being monitored and a display of existing alarm conditions (see Screen 2). This Web interface proved to be quite useful for managers, but it had one drawback ­ most of the managers we worked with spend a large percentage of their time away from a desk. It was time to start considering a wireless mobile solution.

Screen 2: The LRMS Web Interface lets the manager click on the facility's name to see a list of the equipment being monitored and a display of existing alarm conditions.

Creating a mobile solution

As anyone interested in Pocket PCs is aware, the wireless industry has been going in a variety of directions in the last couple of years. As we started exploring the possibility of going wireless, the first thing we had to decide was which handheld platform to go with.