Two-wire intercoms as an alternative to IP intercoms
2023-01-31
In new buildings, IP intercoms with a camera in the door station and an intercom function have become almost a standard. We are talking here not only about single-family housing, but also about housing estates. In fact, one can be tempted to say that in the latter case they are more necessary. In this article, we will answer the most bothering questions that arise before buying an intercom.
Which intercom to choose? What functions do IP intercoms have? Do I need a special installation for the IP intercom?
Going for a walk around the city (or village) in the vicinity of single-family housing, we can observe intercoms with built-in cameras on most fences. Many of them are certainly IP intercoms. This means that these are network devices in which data transmission takes place thanks to UTP cables. These devices are fully configurable, have their own software, thanks to which they work reliably and stably. The intercom set includes: indoor station, outdoor station and PoE switch. The PoE switch is designed to communicate with the indoor station with the outdoor station, and also to power them.
Thanks to this solution, there is no need to lead additional wires to the power supply. If there is already a PoE switch installed in our house, e.g. for monitoring purposes, then we can use the free sockets to connect the intercom. Currently, IP intercoms, in addition to the basic ability to make calls or open the gate, also have other interesting functions. One of them is the ability to connect an intercom with the application. Thanks to this, we can remotely receive calls from the door station, even when we are not at home. We can also open a gate or gate from the application level. Up to five indoor stations can be connected to one door station, which is very useful in multi-family housing (then we have the option of using a multi-subscription outdoor station). Between indoor stations, we can use the intercom function, which allows for free communication between individual tenants. There are also intercoms that have relay inputs and outputs in the internal panels, which allows you to create simple alarm systems with them.
What if we live in a house with an old two- or four-wire intercom system?
In this case, you should choose an intercom in the Two Wire technology. In this technology, thanks to special modules, the IP signal is routed using only two wires. What's more, the same wires are also used to power the indoor and outdoor stations. It is also an ideal solution when the UTP cable was damaged during construction and we do not have a connection on all pairs. In fact, one pair in the UTP cable is enough for the installation to work efficiently over a short distance. The Two Wire intercom has the same functions as the IP intercom with the difference that its connection diagram is slightly different. The heart of the system is a module that can be mounted, for example, on a DIN rail in an electrical box. Connect the indoor and outdoor stations and the LAN cable to it using two wires, if you want the devices to work in the LAN network. If we do not have a LAN cable routed to the electrical box (module mounting location) it is not a problem. We can use an indoor station with a built-in Wi-Fi module and wirelessly connect to the Internet. Up to five indoor stations and one outdoor station can be connected to one module. However, it is possible to combine many modules in order to create a larger network of intercoms, e.g. in apartment blocks. This method is very often used when retrofitting older buildings, where there are usually two or four-wire installations.
Indoor and outdoor stations
Outdoor stations are small devices with great functionality. There are several variants of door stations. Most Popular – modular stations are characterized by the possibility of individual configuration tailored to the needs of residents. To the main outdoor station (camera + bell button) we can connect modules such as: card and proximity chip reader, numeric keypad or list of tenants. As standard, in the case of modular stations, we have a camera with a wide-angle lens and an IR illuminator and two relay outputs (gate + gate).
Indoor stations are touch panels with an elegant appearance. They have a clear and transparent menu. From the level of the internal panel, we can, among other things: answer calls, view the call log, see the preview from the camera in the external station and from the monitoring cameras, if we have one. From the menu level, we can configure the entire intercom, i.e. change the ringtone, volume, call time, etc.