3 Video Walkthroughs: Battery Monitoring, Satellite RTUs, & Redundant Masters

These 3 videos will walk you through 3 different remote-monitoring applications. You'll see how you can:

1. Monitor your batteries.
2. Monitor remote locations using satellite terminals
3. Create geographic redundancy with dual alarm masters that support automatic fail-over.

RTUs with Satellite Terminals

This is a fairly unique application, but you might find it useful. Even if you don't need this exact scenario, there are probably elements that you might use.

This all starts off with the idea that we have alarms. At another site, we want those contact closure alarms to be replicated and in the form of latching and releasing a relay. So how can we pull that off?

In this case, these sites were very remote. You can see that the first thing we did is take a DIN-mounted NetGuardian. That's a nice, compact device that mounts on a DIN rail, which is common in smaller cabinets. We put that RTU inside of a NEMA enclosure so it would be protected from the elements.

This site was so remote that there was no LAN or even cell coverage. That's why we went with a satellite option. We put a weatherproof satellite terminal outside of the NEMA enclosure and ran a network cable to the NetGuardian inside. The satellite terminal just needs a view of the southern sky (if you're in the northern hemisphere).

The terminal then connects up to a satellite in space. In this case, the signal returned to one of 3 other locations that had similar setups. If an alarm signal got sent to the first RTU (as a contact closure), the RTU would use its satellite terminal to alert one of the other sites. That data would be used by whichever RTU received it to latch a corresponding control relay.

That effectively "echoes" the first alarm. When an alarm triggers, a relay latches somewhere else on the planet within 2 seconds. This is a way of transmitting some very basic nuts-and-bolts alarm data - in the form of a contact closure - from one location to another.

This is a pretty rare application, but imagine how you could use some of these components. You could use the satellite transmission and poll a NetGuardian with a more traditional master station. You'd connect to the satellite provider through a VPN tunnel to reach your remote site.

You'd only be paying one monthly data rate for that satellite. You'd be able to monitor a very remote location in a way that terrestrial communication just won't allow.

Dual Masters with Geographic Redundancy and Automatic Fail-Over

Starting from the top, you can see that the master stations in this diagram are collecting information from all of the remote sites on the LAN. There are primary and secondary master stations here. That means, when this first T/Mon LNX is monitoring the network, it will be syncing its information to the secondary.

If anything ever goes wrong with that primary, the secondary will take over. It takes less than a minute. DPS has some clients that use one T/Mon in New York and another in San Francisco, for example.

You can also put both masters in the same rack as one another. That offers some hardware redundancy, but if you can get them in different cities, that's excellent. Then, if a natural disaster or power failure rolls through, you're able to have your secondary off-site and have it continue to function.

These master stations are monitoring NetGuardian 832A RTUs, which full-featured remotes that can take in a pretty healthy amount of different things. You have 32 discrete inputs so you can take in 32 contact closures. You have 8 analog inputs, and two of those analog inputs are used here for a temperature and humidity sensor.

Temp and humidity are obviously very important at any location that may have servers or radios or any other kind of telecom equipment. You have to know that your HVAC is working.

You'll see a NetGuardian 216F. That's another RTU model that supports SFP fiber. You can connect your SFP modules and put this RTU on a fiber ring. When you do that, it will also be able to drop off network for other devices because it has a little switch on the back.

Battery Monitoring System

This is a battery monitoring application. You first need to count up how many of your remote sites have backup battery plants to monitoring. In this example, we have 70 battery strings.

You can see that at location, we have a -48 volt battery string. That is composed of four individual cells (each one would be 12 volts).

Because this battery is the backup power supply at this site, we want to know what's happening. To do that, we use D-wire sensors. These will be collecting the voltage and, in this case, it monitors between 0 and 60 volts. That's appropriate, since we have a -48 VDC string. It's not really going to go beyond that 60-volt range.

D-wire sensors feed into RTUs like the NetGuardians shown here. This diagram lists 3 possible RTU options based on the size of the site: the NetGuardian LT G2, the TempDefender, and the NetGuardian DIN.

The first D-wire sensor is daisy-chained to another one, where we are also collecting temperature and humidity out at the site. These two pieces are bus-powered sensors. They connect to the D-wire port on the RTU, and from there the data is on a network-capable device.

Over LAN, each of the 70 RTUs will be polled by the T/Mon SLIM G2 master station. At that point, you have a single central server that will know the current battery voltage, temperatures, and humidities at all 70 sites.

From there, you have a couple different options. You can look at everything on a screen, which we call Web GFX. That'll be maps and photographs. It's a drill-down interface and that can be really easy, especially new operators. It's very intuitive.

In Web GFX, when an alarm comes in, a little red icon starts blinking. You drill down a couple of levels and you can see just what's happening. You can also have email or SMS text notifications go to your phone or the appropriate technician's phone. Using the built-in web interface, you can also monitor via a list view.

Finally, you can get reports, so you can generate a history of what your battery voltages have been doing over time. You can see a trend. Maybe your batteries are starting to reach the end of their usable life. You need to react to that.

Maybe one site is consistently overheating, so you need to address an HVAC problem. There are simply a lot of different things you can do with remote monitoring.

This is a fairly simple application. We're just monitoring batteries and temperature and humidity. You could also monitor equipment alarms and SNMP traps from other equipment.