Wired Smoke Detector Interface Modules
In general, Alarm Grid recommends avoiding hardwired smoke detectors that require interface modules. There are plenty of 2-wire and 4-wire smoke detectors that can be used without an interface module. Having to add an interface module is just another piece of equipment that makes the setup more complicated and unnecessarily intricate. But there are many smoke detectors that require the use of interface modules, so you may need to add them in certain situations. If you do find that you have a smoke detector that requires the use of an interface module, you may be able to find a compatible module from Alarm Grid. Check with the instruction manual for your smoke detector to find out if the interface module you want to use is compatible.
There are some advantages to use an interface module, but most users find that they are not worth the hassle. One advantage is that the interface module will automatically reset power to the device upon having a fire alarm cleared. This is done by temporarily cutting power to the sensor to complete the reset process. With 2-wire smokes, this is done by connecting the sensor to a designated "smoke detector" zone on a hardwired panel. And on 4-wire smokes, you actually need a power relay. By using a smoke detector that requires an interface module, you can set up the smoke with nearly any system zone, without having to setup an external relay. You can also configure multiple smoke detectors to work with the interface module and have them operate on the same zone.
In most cases, you will only use wired smoke detectors with interface modules with hardwired security systems. If you want a smoke detector for a wireless system, you will usually just find a compatible wireless smoke detector. In that case, you must make sure that the smoke detector operates at a wireless frequency that is compatible with the system. Most wireless systems will have a built-in wireless receiver that accepts signals at a particularly frequency. You should find out what frequency your wireless system uses and determine which wireless smoke detectors will work.
But if you have a hardwired system and you want a way to include multiple smoke detectors on one zone, then an interface module might be for you. Keep in mind that you can also wire 2-wire or 4-wire smoke detectors together at the same zone in parallel. Remember that hardwired smoke detectors are considered normally open devices, so that is why parallel wiring is used. You can then use multiple compatible smoke detectors at the same zone and have them automatically reset with the interface module.