Addressable / Intelligent Initiating Devices
For sake of simplicity, devices will be referred to as "digital" on this page
Conventional Initiation on New Panels
It's very common to see systems that have upgraded the panel, but kept the same devices in the field. How do they do this? Well, for each manufacturer, they make zone monitor modules. These devices take external 24 volt power, and monitor the circuit the same way a conventional panel would. When a conventional device activates, the module converts this into a digital signal that puts the panel in alarm. If the circuit goes into trouble, again the module will convert this so the panel can read and understand it.
Pull Stations
Digital pull stations might sound more complicated than they really are, however the overall concept is the same to that in conventional applications. The reason is that though they connect to the SLC and communicate digitally with the panel, this is really just a monitor module doing the work. The pull station itself is still just using a switch and short circuit. That switch is supervised by a resistor, and if the module in the pull station cannot see it's resistor, it causes a trouble. Upon a short circuit, it causes an alarm. These only require SLC power to operate.
Smoke Detectors
Digital detectors work very differently from conventional detectors. For the most part, these are more of sensors than anything. The panel is constantly getting a reading from the detector, and at a certain chamber value, this will cause an alarm. It's designed to be very simple, but this technology allows modern panels to decide when the detector activates, rather than let the detector decide. This can reduce false alarms.
Furthermore, intelligent detectors are smart enough to know when they need to be cleaned, and will send a trouble to the panel to let the panel know it needs to be cleaned. This again reduces false alarms, ans a dirty conventional detector will often just go into alarm.
Heat Detectors
Similarly, heat detectors in the digital sense are really just heat sensors. Upon a certain temperature, or rate of rise in temperature, the detector will let the panel know that things are getting warm, and the panel will activate.
Though this isn't what we are seeing in the industry yet, it is not far fetched that a heat detector might be able to be used in any application, and a setting be made in the panel for the temperature it activates, rather than the detector.
Others
Now, what about CO detectors? Water-flow? Or anything else we might want to monitor? Well, that's where our trusty modules come in. There are so many types of modules - Mini Monitor, Monitor, Zone Monitor, Dual Monitor, Power Monitor, and the list can just keep going. The fact is that basically any device or situation can be monitored by some kind of module, and then it's just left up to programming in the panel to decide how to handle it. For example, we may have a severe weather pull station, and a water-flow detector tied to the same kind of module, and signals received are the same, but the panel knows the difference between the two thanks to the programming.
Digital CO detection is starting to become more and more common, though it is still very common in older applications to see the CO detectors that are tied to monitor modules