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RTU Tutorial

23 Key RTU Features You Must Understand to Be Successful...

Your RTU's are the front lines of your alarm monitoring system. If you purchase the wrong remotes, you won't have complete visibility of all of your remote sites. If you work with a vendor who can't meet your exact needs, you'll never have a solution that functions ideally. If you buy too large, you will have overspent on features you don't need. Buy too small, and you won't have the point capacity and functionality you need to monitor effectively. If you don't make any decision, you are exposing your company to risk. This handy guide will help you identify the important criteria you must consider when purchasing new RTU's. It will help you to identify the true needs of your remote sites, teaching you how to select a remote that will give you the visibility you need to do your job well. You'll even learn the secrets of choosing a vendor capable of custom-designing your perfect-fit RTU.

Executive Summary.
Finding the right RTU can be a long and difficult process. With so much of your bottom line resting on top-quality monitoring, you can't afford to make the wrong decision.

This guide teaches you what you must know to make the right RTU decisions for your network. You'll learn how to analyze your remote sites to determine what RTU features you need, and what you will never use and shouldn't pay extra for.

To further assist you in your buying process, you'll also learn about six extra criteria that you should seek in an alarm monitoring vendor. By working with the right vendor, you will receive the best products and best service for your monitoring investment.


  1. The Role of an RTU
  2. 23 Things to Look for in an RTU

The Role of a Remote Telemetry Unit (RTU).

Your alarm monitoring remotes are the front line of your monitoring system. They are responsible for collecting alarms from your gear to provide you with the crucial alarm alerts that help you to maximize revenues by minimizing network downtime. If you don't have the needed point capacity, or the right kind of transport, you will never have complete network visibility.

Your RTU's are the collection centers for all of your mission-critical network alarms. They interface directly with your revenue generating gear.

Alarms are collected by your network of remotes, and then forwarded to your top-level master. Advanced masters can then output these alarms to your network staff on-screen, though the web browser interface, or via email and pager alarm notifications.

23 Things to Look for in an RTU.

# 1 - Point Capacity Requirements.
How many single alarm points will you need to monitor? The first step in developing your monitoring system and selecting the perfect RTU is to determine the discrete alarm point capacity needs for each of your unique sites.

Discrete alarms are the simple 'on' and 'off' alarms in use at your site. More often than not, you'll need a varying number of these discrete alarm inputs at your different remote sites. However, don't seek out 45 different configurations if you have 45 different sites. Instead, look for natural break points, such as dividing your sites into 'small', 'medium', and 'large' groups. This will make sparing easier and reduce the time it takes your technicians to learn how to wire your RTU's.

Correctly estimating your company's monitoring needs is a crucial part of maximizing your monitoring investment. While you don't want to pay for excess capacity that you won't use, you need to think several years ahead when planning your monitoring system. You don't want to go with a remote that is too small, as you must leave room for your sites to grow. Therefore, when selecting a remote, you want to choose an RTU with a capacity that coincides with your company's overall plan for business growth. On a more technical note, deploy a remote that allows for reversible alarms, allowing for operation in both N/C and N/O configurations.

# 2 - Need for Analogs.
Do environmental factors play a role in your network uptime? Do your mission-critical devices rely on battery or generator power? If so, analogs are very important to your success.

Not every alarm condition can be represented by a digital "on" and "off". Analogs provide you with the ability to monitor environmental factors that affect your operations. These inputs can measure and answer the question "how much?". Common examples of analog values include temperature, battery voltages, humidity, and many more. By knowing when these factors cross vital thresholds and their rate of change, you can take action before these conditions affect the connectivity of your network, such as bringing in a portable generator if your batteries run low.

Your RTU should provide several of these inputs. You will also benefit from deploying advanced remotes that provide analog alarm notifications using major and minor thresholds. These user-defined values will help you to distinguish the severity of alarms by indicating when a monitored analog has passed a certain value, such as a major temperature high that threatens your gear.

Awareness of the severity of these alarms will help you to more effectively dispatch your maintenance technicians and maximize your network uptime.

# 3 - Control Relays.
Do you need to adjust the on-off status of your gear remotely? With control relays, you can gain the control you need of these devices.

Control relays allow you to remotely switch gear on and off. They are simply a switch mechanism that can be activated remotely, no matter where you are located. This can be used for anything from light switches to generators to door locks and more. You'll also want to make sure that your RTU supports both N/O and N/C so that if power fails, relay will return to intended operation.

Your RTU should support include both momentary operation, similar to pushing a button, and latched operation, like flipping a switch. Finally, make sure your relays can handle 1 amp and 30V DC, as well as the voltage requirements needed to remotely control your devices.

# 4 - Ping Alarms.
How will you know if your mission-critical gear and devices aren't transmitting data? With advanced RTU's that provide ping alarm capabilities, you'll be the first to know when there is a communication failure.

Ping alarms occur when a ping is sent out to a network device. If a device fails to ping back, a ping alarm is sent just like any other alarm notification. This way, your technicians will receive a pager or email alert informing them of the problem before it becomes a major issue.

While many system masters provide ping alarm functionality, the most advanced remotes can also provide you with this valuable tool for your network visibility. The benefit of using your RTU's for conducting pings is that doing so will reduce your overall network traffic.

If you ping all of your devices using your alarm master, these pings and ping alarms have to travel all the way down your entire network architecture, generating a great deal of traffic along your network. If you ping site devices using your RTU's, these pings will only have to travel a short distance down the network, freeing much of the traffic. Your remote can then alert you via alarm master, pager, email, cell phone, or web interface when a user-defined number of consecutive pings to a device fail.

# 5 - Site Connectivity.
How will you bring alarms back to your central office? You need a remote that can use your existing LAN, dial-up, T1 transport, or dedicated circuits.

You should never have to upgrade your transmission method just to be compatible with your remotes. That is an expensive process, in time and budget. Instead, you should seek a remote that will adapt to your needs.

The most advanced remotes offer a lot of transport options. This allows you to use what's available, and then simply change your remote over to a more advanced connection as your network grows.

These remotes are cost-effective, because they allow you to slowly expand your LAN network outward as you can afford to do so, while using your existing monitoring gear. With a lot of transport options, you'll never have to perform an expensive forklift swap out of your remotes, costing out your monitoring system over several budget cycles.

# 6 - Site Climate.
Do your remote sites run the risk of being snowed in? Does the humidity in your location reach extreme highs?

If so, site climate is an important issue that you must address when selecting a remote. Rugged engineering allows advanced remotes to perform in the harshest conditions. You must investigate your vendor's production process to ensure that their remotes are of the highest quality, and that they are built to withstand extreme high and low temperatures, as well as humidity and other factors that are relevant in your region.

# 7 - Remote Provisioning and Firmware Updates.
Do you have a large number of distant sites? If this is the case with your network, remote provisioning and firmware updates will save you a great deal of windshield time, the time your highly paid technicians spend driving to and from remote sites.

You absolutely must have an RTU with upgradeable firmware, so don't settle for non-firmware upgradeable remotes that require you to get a chip directly from the manufacturer. Instead, find a unit with upgradeable firmware. Better yet, deploy an RTU that is remotely upgradeable with LAN. By remotely accessing your RTU's for setup and firmware upgrades, you will eliminate the need to send a technician out to distant sites for every firmware upgrade. Your remotes will be accessible right from your PC workstation, enabling you to update all of your RTU's right from your central office. For the optimum RTU performance, seek the most advanced units that allow you to perform these updates in bulk-mode without attending to the process. Hint: Make sure you don't have to have somebody camp out on a screen to upgrade your firmware to your full RTU network. Look for an RTU that supports unattended bulk firmware updates.

# 8 - Web Interface.
Selecting a remote with a web interface will provide you with the access you and your technicians need without the hassle of granting NOC access to every user. Direct access to the site is fast and simple through a web interface. There's no special software to load on technicians' laptops and workstations, and because everyone knows how to access it, the web browser interface is easy to use.

Advanced remotes provide these web interfaces, which allow you to access your alarm information from any workstation on the network. This allows you to monitor your sites without a master in smaller networks. It also allows your technicians to see just one site's alarms, eliminating confusion with alarms at other remote locations. Make sure your remote provides you with a browser interface that is password protected, so you can be sure your important alarm data is secured.

# 9 - Pager and Email Alerts.
Do you need to be able to receive instant alarm notifications away from the office? Do you need to receive alarm notifications, but you don't have a master? With advanced remotes, you can get the alerts you need.

Select RTU's that support pager and email alerts that are sent to your network technicians automatically when an alarm occurs. These messages give you important alarm point location details to help your technicians quickly identify problems.

Even if you don't have a master in your network, these advanced RTU's will provide you with first-tier alarm notifications. This functionality also provides for a great contingency in the event that your alarm master or communication path fails.

Advanced RTU's will allow you to program alerts for specific alarms points to be sent to specific technicians. This will allow you to send your building access alarms to your security staff, while sending your environmental alarms to your technicians based closest to your site.

# 10 - Open Protocol Support.
If you don't want to get locked into to a single vendor's line of gear, don't purchase remotes that use proprietary protocol communications. Don't be one of the many companies trapped on an old monitoring platform because of your vast RTU deployment. What if that company stops supporting your gear, or goes away? Instead, deploy open-protocol remotes in the first place. This give you the freedom to change gear and vendors when you need to.

When your RTU's support an open-source protocol, such as SNMP, they can report to any compatible master. In the case of SNMP, one of the most common open-source protocols, this will allow you to direct your alarm reporting to your existing SNMP manager rather than having to deploy a new one. When you are ready to upgrade your master, because your remotes support open protocols, you will have many more deployment options. This will enable you to utilize the most advanced alarm masters without having to purchase a new fleet of RTU's.

#11 - Derived Alarms and Controls.
Derived alarms are software-based alarms that occur whenever a user-defined combo of events occurs. Commercial power failure at an enclosure might be a minor alarm. Low battery at an enclosure might be a minor alarm. But the combo of a power failure and a low battery should be reported as a critical alarm, and derived controls allow you to do just that.

Derived controls take this concept one step further. They are automatic responses to alarm combinations. In the example above, you could setup a simultaneous power failure and low battery to automatically latch a control relay tied to a backup generator. This kind of advanced automation corrects network threats within seconds, protecting mission-critical gear and keeping your client base happy.

There are two kinds of derived control operation, and a good RTU supports both. The first is "reflexive mode", and it is handled completely on-site. The RTU considers currently standing alarms and latches controls as it has been programmed. This mode is powerful because it is so simple. If the connection to your alarm master fails, smart on-site decisions can still be made automatically.

"Master mode" is the second kind of derived control operation. In this mode, an RTU simply reports alarms normally to the master. The master considers alarms from the enclosure, as well as the status of the entire network, and makes an informed decision based on comprehensive network analysis.

#12 - Integrated Hub.
Are you short on rack space? Do you need to access other devices? If so, find an RTU with an integrated Hub. This will help you save rack space by eliminating the need for a dedicated switch. This will also eliminate the costs associated with purchasing a switch. With an integrated Hub, your equipment is on protected DC power, instead of vulnerable commercial AC.

#13 - Required Certification and Compliance.
What certifications are important to your company? What criteria must a vendor meet to sell their gear in your location?

Network alarm monitoring is critically important to a number of industries, and national governments have taken measures to ensure the proper operation of this gear. Some vendors have also taken it upon themselves to self-regulate, voluntarily complying with best practices. There are many different certifications that can be obtained for remotes, and many different regulations and standards that RTU's should be compliant with. These include safety, FCC, emissions, NEBS, CE, and RoHS.

Before you select an RTU, determine which regulations apply to your company. Seek a remote that meets the criteria outlined in these codes to make sure your visibility needs are being met.

#14 - Serial Reach Through.
Do you need access legacy serial devices at your site? If you do, it is important that you find an RTU with reach-through serial ports. This will ensure that you can access your important serial devices.

Not all gear is LAN accessible. Serial access will enable your staff to quickly repair your network without having to be physically present at your network site, saving you expensive windshield time while maximizing your network reliability.

Serial-reach through also eliminates the expense and space requirements of a dedicated terminal server. Thus, the presence of these ports in advanced remotes offers major cost savings. This serial-reach through can also save you from excessive downtime in the event of a primary path communication failure, because unlike a separate terminal server, your serial-reach remotes will provide for alternate path reporting to keep your network visibility secure.

#15 - Visual and Audible Alerts.
Do you need to see your alarms while you're on-site? While automatic alerts and alarm displays in your master workstation are the most effective way to receive alarm notifications, sometimes it can be helpful to simply view site alarms right from your remote. Nothing is worse than going to a site and troubleshooting a device with no indicators. PC's take time to setup, and not all technicians have them.

In these cases, you'll need an RTU that provides alarm indicators right on the hardware. These can be LED lights, LCD screens, or even a small audio output that allow you to hear incoming alarms as an actual alarm noise. These visual and auditory cues provide a helpful final checkpoint for your technicians before they leave a site, or to lead them straight to the problem when they arrive.

LCD screens are most helpful, as they offer you specific alarm information. While LEDs will direct your site technician to an alarm point number, remotes with LCDs can display your user-specified alarm names, reducing the time it will take your technician to identify and correct the problem. This will also prevent unnecessary truck rolls, because technicians can fix problems locally before leaving, eliminating the need to return to the site.

#16 - Choice of Termination Method.
What tools do your technicians have available? How do you want to terminate your alarm wiring? You have a choice, and you should seek an RTU that provides you with your preferred termination method.

There are a number of termination methods available to your when selecting a remote. Some devices offer wire-wrapped back panels for easy installation. Others offer hinged back panels. You could also connect your RTU using amphenols. Each of these termination methods provides unique advantages to different remote sites.

To provide for the most cost-effective termination of your new RTU's, you'll want to choose a termination method that allows your technicians to use the tools they already have. Different installation tools also provide for different qualities of connection, so you will need to decide whether you want a speedy installation using punch down tools, or a higher-quality install using wire-wraps. Once you have determined these criteria, select an RTU that gives you the benefits that are most important to your network.

#17 - Security.
Do different users need different levels of access to your network monitoring system? Do you want to secure your remotes from being accidentally reconfigured by a low-level technicians, or prevent a non-employee from accessing your vital alarming data?

If so, you need to deploy a remote with the proper security features in place. Make sure your remote protects access from unwanted users, while still providing your technicians the access they need.

#18 - Alarm Qualification to Prevent Nuisance Alarms.
Is your monitoring filled with distracting "nuisance" alarms that can make real problems hard to see? You can reduce the distraction of these nuisance alarms with alarm qualification times.

If you are plagued by persistent, meaningless alarms from frequently active points, you will need to find a remote that can distinguish your important alarms from these nuisance alarms. Without qualification times, your technicians are trained to ignore your important alarms.

Alarm qualification times allow you to program your remotes to ignore alarms that clear within a certain time interval. Why wake someone up just to say "nevermind" 90 seconds later? If a device is known to set off a momentary alarm every few minutes, you could program it not to send an alarm notification unless an alarm stands for longer than 30 seconds.

This can be particularly helpful in reducing the number of alarms to process in your master station. It will also prevent your NOC personnel from being desensitized by frequent non-critical alerts.

#19 - Windows Provisioning Software.
Can your RTU be configured with a convenient Windows application? It should, because if you ever lose an RTU, you don't want to lose the database. With Windows provisioning software, you can set up an RTU from any Windows PC. Make sure the configuration software can store configuration data for every site, otherwise it is too tough to manage.

This can be very handy, as it allows you to remotely provision your RTU's anywhere you have access to a Windows PC, not simply from your master workstation.

#20 - Chassis Size/Mounting.
Are your gear racks getting full? Is your gear stored in small cabinet enclosures?

While it may seem like a minor detail, you do need a remote that physically fits into the space you have available. You shouldn't have to purchase new gear racks to accommodate the size of your RTU's.

Instead, seek out a vendor with remotes designed to compactly accommodate the unique needs of your sites. However, be careful not to sacrifice monitoring capacity just to reduce physical size. While you may only have a single rack unit of space available, you must still be able to provide for all of your visibility needs. Also, consider wall-mountable RTU's, or MDF mounting, which will help you work around your rack space limitations.

#21 - Real-Time Clock.
Do you need to know the exact time of alarm events? Generally, it is important to keep accurate logs of your alarm events. Thus, it is important to deploy an RTU with a real-time clock.

This will enable your remote to timestamp your alarms and provide you with a detailed log of the exact times and dates that alarms occurred. This information can become vital later as you analyze frequently occurring alarms and determine the appropriate preventative measures. Even better, make sure the RTU keeps a local log so that technicians can track the source of the problem and audit your NOC alarms.

An advanced remote should also offer you the option to synchronize your unit to Network Time Protocol. When this option is selected, the RTU will periodically synchronize its internal clock with an NTP server on the Internet. This will keep your entire alarm monitoring system to a consistent timekeeping standard. With this feature, you'll never have to enter the date and time into your fleet of remotes.

#22 - Site-Powered.
Do you want to use battery power for your remote site RTU's? If so, you need to find a device that will accommodate this need, and look for an RTU that is compatible with your battery plant, either +24 VDC or -48 VDC. If you purchase a remote that isn't compatible, you will be running site power through a transformer, and that's another piece of gear you'll have to purchase and squeeze in your enclosure.

If your gear is important enough to require dual power, you should protect your RTUs with dual power as well. This will keep your vital alarming running during a power failure when you need it most.

#23 - Alternate Path Reporting.
What happens when you lose your primary network connection? Can you afford to lose your alarm monitoring? If you need to maintain visibility of your alarm points, you need an RTU that supports reporting along an alternate path, such as serial or dial-up.

RTU Glossary

Alarm Termination Method
How your alarm gear is wired and installed for deployment. Some termination options include: wire-wrapped back panels, hinged back panels, and amphenol cables.

Alternate Path Reporting.
An RTU's ability to send alarm data via a secondary path when primary path communication fails. Examples of alternate path options are serial and dial-up.

Analog Inputs
Analogs inputs collect data and allow you to monitor environmental factors that affect your operations. These inputs can measure a wide variety of analog values, including temperature, battery voltages, humidity, and many more.

Analog Thresholds
User-defined values that indicate the severity of alarms by indicating when a monitored analog has passed a certain value, either a minor over or under, or a major over or under.

Control Relays
Control relays are switch mechanisms that allow you to remotely switch equipment on and off. They can be used for anything from light switches to generators to door locks and more.

Derived Controls
Derived controls are user-defined automatic responses to certain alarm combinations. These derived controls allow control relays to respond to data from analog inputs that are designed to measure environmental factors.

Discrete Inputs
Discrete alarms inputs collect simple 'on' and 'off' alarm data at your sites.

Integrated Switch
Additional gear switch located with an RTU. It eliminates the need to purchasing a dedicated switch. Integrated switches operate on protected DC power, instead of vulnerable commercial AC.

Serial Reach Through
Serial-reach through eliminates the expense and space requirements of a dedicated terminal server by providing you access to your serial devices directly through your RTU.

Site Powered
An RTU's ability to use battery power at remote sites, most likely through a protected dual power feed.

Updateable Firmware
Firmware that can be updated as newer versions are released. These updates are most useful when they can be scripted over LAN.

Web Interface
Allows you to view alarms right from your RTU through a browser window.