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How To Choose an RTU For Your Enclosure Site

By Morgana Siggins

December 7, 2020


The RTU is an important part of a complete monitoring system, as they collect alarms from your mission-critical equipment and forward them to an alarm monitoring master. In smaller and medium-sized networks, a single RTU unit can even function independently to provide you with network visibility.

If you have enclosure sites, an RTU will help you to monitor your network devices, letting you be the first to know when there is a problem with your data transmission. But, you need to be sure you're investing in an efficient device. For that, you need to know just what you need to look for.

Finding the perfect RTU for monitoring your enclosure sites shouldn't be a gamble. Learn how to assess your network monitoring needs and review all the criteria you need to consider when shopping for an RTU.

RTU for enclosure sites
Take a look at the main points you should keep in mind when choosing a remote terminal unit to monitor your enclosure sites.

Point Capacity Requirements

The first step in your RTU deployment is to determine the number of alarm point inputs you'll need at your enclosure sites.

If you have a number of unique sites, you'll most likely require a differing alarm input capacity at each site. While it may seem appropriate to deploy a number of unique configurations for all of your enclosure sites, it isn't advisable.

You're better off seeking out natural breaking points and dividing your sites into small, medium, and large capacities. This will make sparing easier by speeding the learning process for your technicians as they learn how to wire your remotes.

To maximize your monitoring investment, it is critical that you correctly estimate your company's monitoring capacity needs. While you shouldn't spend on the excess capacity that won't be used in your network, you should plan several years ahead when developing your monitoring system.

RTU capacity
It's important to add extra discrete alarm inputs to allow for future growth, commonly about 15% of your calculated immediate need.

Going with too small an RTU won't leave the room you need for enclosure site monitoring to grow. You will want to choose a remote that provides alarm point capacity that matches your network growth plans in the future.

At DPS, we manufacture expansion units that are compatible with our RTUs - the NetGuardian DX. This means that you won't have to deploy more and more units as your network grows, this low-cost solution will provide you with additional discrete alarms.

Need for Analogs

A simple "on and off" can't properly represent some alarm conditions. For these types of alarms, analog inputs will give you more detailed monitoring of environmental factors at your enclosure sites.

Analog inputs can measure an assortment of values, including temperature, battery voltages, humidity, and many more. By knowing when these factors cross critical thresholds, you can adjust the temperature or take action before your batteries run down. This means that you'll better visibility to correct conditions that have an adverse effect on the equipment at your enclosure sites.

So, when selecting an RTU, it's important to look for one that offers several analog inputs. Advanced devices that support these alarms using major and minor thresholds will be even more effective.

These user-defined values will help you to distinguish the severity of alarms by indicating when a monitored analog has passed a certain value. This can be either somewhat above or below, or critically above or below a certain level, such as a major temperature reading that threatens your gear.

Being aware of the severity of your analog alarms will enable you to dispatch your maintenance technicians in the most efficient manner, minimizing your truck roll costs and network downtime.

Control Relays

Controls relays are switch mechanisms that allow you to remotely toggle your enclosure site equipment on and off. They can be activated from any location using your master station. This functionality is beneficial in monitoring anything from light switches to generators, and more.

It's also important that your RTU supports both N/O and N/C so that, if the power fails, the relay will return to the intended operation. Those methods should include both momentary operation, similar to pushing a button, and support for latched operations like a switch.

Finally, make note of the voltage requirements needed to remotely control your devices, and deploy an RTU that is compatible.

Derived Alarms and Controls

Derived controls are user-defined automatic responses by your enclosure site equipment to certain alarm combinations. These control relays can instantaneously resolve certain network issues and reduce your network downtime by combining with analog inputs used for monitoring environmental factors.

For example, if you lost power at your enclosure site and the generator failed, you could program a control relay to power on the backup generator when these two problems occur in unison. This is extremely helpful in reducing network downtime and keeping your mission-critical equipment online. This added reliability will also keep your client base happy.

It's important to make sure your RTUs can operate in "reflexive mode", enabling them to make instant decisions at your site without master interaction to save you time when you encounter a network failure. When power fails, your generator will be activated by your RTU, which will report the occurrence to your master station immediately.

Modern RTUs can also operate in "master mode". This means the ability to generate a total view of your network to make more informed decisions. In a power failure situation, for example, your RTU will be capable of alerting the master station - which will send an automatic control response to the site. Using this complete view of the network, your device will be able to make the most effective response within your total network.

Site Connectivity

What kind of communication transmission method do you already have in your sites?

The best practice is to seek out an RTU that can use your existing LAN, dial-up, T1 transport, or dedicated circuits. It's not cost-effective to upgrade your transmission method just to be compatible with your RTUs. That's an expensive process, both in terms of time and budget. To maximize your monitoring investment, you should deploy an RTU that will adapt to your transmission methods.

Modern RTUs will be equipped with a variety of data transport options. When you have options, you can deploy your units using your existing transport method. Then, simply reconfigure your RTU over to the latest connection as your network expands to include more of your enclosure sites.

This type of deployment will save you money by providing for your gradual LAN migration towards your enclosure sites while using your existing monitoring equipment until you can afford to replace it. With multiple transport options, you won't need to perform an expensive forklift swap out of all your RTUs. Instead, you'll be able to purchase new equipment as your budget allows over several cycles.

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Open Protocol Support

Deploying RTUs that support open protocols gives you the freedom to change vendors and equipment as you please. Usually, when you purchase RTUs that use proprietary protocols, you get locked into a specific product line of monitoring gear.

There are several reasons why it's important for your equipment to support open-source communication protocols, such as SNMP.

When your RTUs support an open protocol, they can forward device alarms to any master station. This allows you to direct your alarm reporting to your existing master rather than deploying a new one.

Whenever you are ready to upgrade your master, you will have many more options because your RTUs support open protocols. This will enable you to upgrade to the most advanced master station while eliminating the need to purchase all new RTUs for your enclosure sites.

Site Climate

If your enclosure sites are exposed to harsh temperature or humidity levels, then the climate is an important factor you should take into consideration when selecting an RTU.

Field-proven engineering ensures that advanced monitoring units can perform in the harshest conditions. So, it's important that you investigate your vendor's production process to be confident that they utilize rugged engineering tactics to provide you with RTUs that are built to withstand extremely high and low temperatures, as well as humidity and other factors that are of critical importance for the enclosure site's region.

Remote Provisioning and Firmware Updates

If you have a large number of distant enclosure sites, remote provisioning and firmware updates will save you a great deal of windshield time. This is the time your technicians spend driving to and from remote sites.

With remote access to your RTUs for setup and firmware upgrades, you won't need to send a tech out to your distant sites every time you want to upgrade your firmware. You will be able to access your units from your PC workstation and update all of your RTUs right from your central office.

If you need this functionality, then avoid deploying non-firmware upgradeable RTUs that require you to get a chip directly from the manufacturer. Instead, invest in a device that allows you to avoid site visits entirely when performing these updates.

Firmware that is upgradeable via LAN is more efficient. Particularly advanced RTUs that allow you to perform these updates in bulk-mode without sitting in from of your monitor confirming each individual site upgrade.

When you invest in a DPS device, you can download your firmware updates for free directly from our website.

Web Interface

To avoid the hassle of granting NOC access to every user, select an RTU with a web interface that will provide you and your techs with the access you need. Gaining direct access to the site is fast and simple through an RTU's web interface.

Advanced RTUs will allow you to access your alarm information from any workstation on the network through a web interface. This way, you can monitor your enclosure site equipment without a master in smaller networks. It also allows your techs to see a single enclosure's alarms, avoiding confusing alarms at other remote locations.

Text Messages and Email Alerts

Efficient RTUs provide automatic text message and email alerts that are sent to your network techs when an alarm occurs at one of your enclosure sites. These messages give you important details that will help you to quickly identify and correct problems.

Even if you don't have a master station in your network, these RTUs will provide first-tier alarm notifications. This is also a great back-up in the event that your master or communication path fails.

Make sure your RTU allows you to schedule notifications for specific inputs to be sent to specific techs. This allows you to set the alarm distribution in whatever criteria that makes sense to your company. For example, you can send your building access alarms to your security staff, while sending your environmental alarms to your techs based closest to your site.

Alarm Qualification to Prevent Nuisance Alarms

You can reduce the distraction of nuisance alarms at your enclosure sites with alarm qualification times.

If you are constantly receiving meaningless alarms from frequently active points, you should seek an RTU that can distinguish your important alarms from distracting nuisance alarms. If you don't your techs will become trained to ignore your important alarms.

Alarm qualification times allow you to provision your RTUs to bypass alarm notifications for alarms that clear within a certain time interval. There is simply no nonsense waking someone up, only to say "never mind" 90 seconds later.

If a device is known to set off a momentary alarm every few minutes, you can program it not to send an alarm notification unless an alarm stands for longer than 30 seconds.

Alarm qualification times are very helpful in reducing the presence of nuisance alarms in your master station. It will also prevent your techs from becoming desensitized by frequent repetition of unimportant notifications.

Integrated Switch

Whether you're lacking available rack space, or need access to additional devices, find an RTU with an integrated switch.

An integrated switch saves you rack space at your enclosure site by eliminating the need for a dedicated switch, which also eliminates the cost of purchasing it. Another benefit of an integrated switch is that it is on protected DC power, instead of vulnerable commercial AC.

Serial Reach Through

An RTU with reach-through serial access allows you to reach legacy serial devices at your enclosure sites right through your monitoring unit. This provides needed access to your important serial equipment.

You'll save expensive windshield time while maximizing your network reliability with serial access. It will enable your team to quickly repair your network without having to be physically present at the enclosure site.

This serial access also eliminates the expense and space needed for a dedicated terminal server. You can simply connect to your network through any of your serial devices using terminal software. Thus, the presence of these ports in advanced RTUs offers major cost savings.

Choice of Termination Method

For an optimum deployment, you should seek an RTU that provides you with your preferred termination method.

When shopping for an RTU, you'll notice that there are a number of termination methods available to you. Some units offer wire-wrapped back panels for easy installation. Others offer hinged back panels. Amphenols are another termination option available with some RTUs.

Each of these methods provides unique advantages to different enclosure sites. So, it's critical to select an RTU that gives you the benefits that are most important to your network.

We Can Help You Find a Perfect-Fit Device

Finding the perfect RTU is easier when you know exactly what you need. However, all the previous factors that you should consider before buying an RTU for your enclosure site certainly makes a long list. This might be intimidating when you still have all your job tasks to do.

Take a look at a list of DPS RTUs.

Your enclosure sites can't be left unprotected though. That's why we take on the job to analyze your network and come up with a perfect-fit RTU that will meet all your requirements. In fact, we do everything in-house, so our specialty is building custom monitoring solutions.

So, talk to our experts and get an efficient, custom RTU with a money-back guarantee.

Morgana Siggins

Morgana Siggins

Morgana Siggins is a marketing writer, content creator, and documentation specialist at DPS Telecom. She has created over 200 blog articles and videos sharing her years of experience in the remote monitoring industry.