Remote Site Environmental Monitoring - How You Can Get Started

Environmental monitoring at your remote equipment sites is a critical part of keeping your network online. "Environmental monitoring" means any monitoring of the physical environment around your network equipment and/or servers (as opposed to direct equipment monitoring, which involves only equipment failures and problems not caused by adverse environmental conditions around your equipment).

A variety of adverse conditions can take down your expensive infrastructure, especially in very remote sites that may be on top of mountains. Because your sites are so remote, it's even more important to implement effective environmental monitoring. No one is stationed at these sites, so you need an automated system to monitor the critical environmental level surrounding your infrastructure equipment.

Probably the most commonly monitored environmental level in both telecom and IT spheres is temperature. High temperatures generally regarded as the bigger threat, because all computer equipment naturally generates large quantities of heat. If this heat is not reduced through venting and HVAC systems, your equipment can be damaged or, at minimum, suffer a thermal shutdown that will cause an interruption in service.

Did you know, however, the cold temperature is actually a very big concern at high elevations in the northern latitudes? In this case, a heater takes on the temperature controlling role normally fulfilled by an HVAC system.

At both temperature extremes, a failure of your climate control system can lead unacceptable network downtime. That's what makes environmental monitoring (temperature monitoring in this case) so important at all of your remote sites.

So how do you go about implementing environmental monitoring for temperature level at your sites? The first thing you need to do is select a temperature sensor. Temperature sensors basically fall into one of two different types: analog and discrete. Discrete sensors output only a simple on or off indication. Much like your home thermostat, you can specify a specific temperature that separates acceptable temperature from unacceptable temperature.

Analog temperature sensors are generally much more preferable for use in environmental monitoring systems. They have a much higher level of detail than a discrete sensor. Analog temperature sensors can tell you exactly how hot or cold it is at your sites (usually within about 1 degree and within the specified minimum & maximum temperatures measurable by the sensor). With an analog sensor, you can actively conduct environmental monitoring at any time by checking the current temperature level.

Since you can't always be watching a temperature sensor, your alarm remote being used for environmental monitoring must also be able to send you alerts when temperature crosses critical thresholds. At minimum, you must be able to configure two temperature thresholds. This forms a decent foundation for environmental monitoring, since you'll be able to set up an alert for "too hot" and another for "too cold". Better alarm remotes will have support additional thresholds, so you can set up both "major" and "minor" severities on both sides of your ideal temperature range.

Environmental monitoring also includes humidity monitoring. This is critical in climates where relative humidity (water in the air) can rise to nearly 100% of air's capacity to hold moisture. When humidity in a site exceeds acceptable levels for the equipment stationed there (usually anything over 90% will cause trouble for quite a bit of gear), your ability to keep your network online diminishes. That's why a simple analog humidity sensor is an important tool for effective environmental monitoring. Fortunately, you can purchase combination sensor units specifically designed for environmental monitoring at equipment sites. These devices include both temperature and humidity sensors in a single package, requiring just one power source.

Similar to humidity (but much more dangerous) is floor water. If you have a leak that lets in rain water or seasonal flooding at your sites, a floor water sensor will give you important intelligence about which sites have puddles of water on their floors. One type of floor water sensor has about 4 metal contacts on its underside. These make contact with the floor. If a puddle of water connects any of these contacts (about 2 inches apart), the sensor will detect a small current flowing between the contacts (water is, of course, a good conductor of electricity).

Other floor water sensors also use an electrical current to monitor the floor for water, but they do it in a very different way that gives you much more floor coverage. These are rope-based humidity sensors, which can detect even a single drop of water that touches their specially designed ropes that can be many feet long. The rope wicks water to electrical sensors, which then detect current flow and the presence of water.

Unlike both temperature and humidity sensors, which are better in analog forms, there really is no common reason to design or use an analog floor water sensor. Your floor either has water on it or it doesn't. Theoretically you could used a float sensor in your site to monitor flood water levels, but this would only be used in extreme cases where semi-regular flooding is expected and equipment racks have been installed above a certain minimum height. In this case, monitoring rising water would give you the required notice that equipment, successfully operating above water on the floor, was about to be underwater.

On the fringe of environmental monitoring is the subcategory known as "security monitoring." This includes, most commonly, door sensors and motion sensors. Since intruders are not equipment to be monitored, they fit the strict definition of "environmental monitoring." Just like floor water sensors, both door sensors and motion sensors are perfectly adequate and most common in discrete form. Knowing how much motion or how much door opening you have isn't really important. An intruder is an intruder.

Using IP cameras in combination with intrusion sensors can, however, give you important detail. Did a wild animal trip your motion sensor? Did the wind rattle a loose door sensor? Is the weather on top of the mountain clear enough to send a maintenance team in a helicopter? Since a picture is worth a thousand words, IP cameras add a lot of value to your environmental monitoring system.

The DPS approach to environmental monitoring involves one of two alarm remote families: NetGuardian or TempDefender.

The NetGuardian family of RTUs is primarily used in industrial telecom environments. Most models have analog inputs (either 0-5 volts DC or 4-20mA), making them well suited for environmental monitoring.

The TempDefender is more commonly used in IT locations like server rooms, server closets, and data centers. It ships in a compact metal chassis, and supports daisy-chainable sensors that receive power and send/receive data all over a single wire. This increases your flexibility to position sensors where they will be most effective.

Actual environmental monitoring projects
One DPS client, Dan, asked for a quote for an environmental monitoring system. They contracted with a large telco to provide monitoring via the internal alarms of their equipment, but that deal ended. Dan's primary concern was bringing his environmentals (10 or less discretes) to his central site via CDPD modems. He said it would be critical to have a central master dial up and poll each site every half hour. Dan wanted to have alarms presented over the LAN with up to 4 concurrent users. At the remote sites, he preferred -24v (DC). At the master site he wanted 110v (AC). They had 100 remote sites and growing.

Another DPS client, Craig, had a variety of important monitoring needs, including environmental monitoring. He needed to:

• Monitor Microwave and IP Equipment as well as Environmental alarms
• Remove the confusion of who is on call
• Move to 24/7 full time NOC and give a "War Room" display for alarms

Benefits of a good solution would be:

• Monitor critical equipment and envrironmental alarms from across 11 islands
• Allow email, text message, and audibly voice notifications to numerous users depending on who is on call at different schedules
• View different levels of alarm activity. For example, view the RF side, Network, and Remote Sites status from a basic view on a map. Then drill down and view great detail with different map views.

In Craig's case, we asked him to consider these questions so that we could make the best possible equipment recommendation:

• How would you like to power the T/Mon LNX, is this 110VAC or -48VDC?
• Would it be helpful if we showed pricing for travel to your site for Turn-Up and Training assistance?
• We would like to show you a web-demonstration of the T/Mon LNX, when would be a good day and time? And how many people on your end need to attend? Please let me know and I will reserve a conference bridge for you and your team to log on and view the live demonstration. I'm looking forward to your feedback.

(If you'd like a live web demonstration of DPS equipment, visit our meetings page for more information.

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