An intercom system allows personal contact with visitors without the need to physically answer the door. They also provide a sense of security by allowing homeowners and building occupants to determine who’s at the door before letting them in.
An intercom, talkback, or door phone is a stand-alone voice communication system for use within a building or small collection of buildings, functioning independently of the public telephone network. Most intercom systems are stationary and fixed to a wall or stationed on a desk.
audio/video intercom systems
There are simple house intercoms and intercoms developed for blocks of flats. Some are equipped with video, and their wiring can be connected to the outside. The most recent generations of intercom systems are compatible with computers and models include TCP/IP.
Many schools and office buildings now use audio/video intercom systems that can be interfaced with the building’s access control system to identify visitors trying to gain access to a locked building.
Door Phones
A door phone is a two-way intercom allowing communication from the street to the house
A door phone in its most basic version is a two-way intercom allowing communication from the street to the house, with the possibility of unlocking and opening the door and allowing access to the interior of the building.
They are so widely used that nowadays they form part of the standard electrical installation of most commercial buildings. In places where there is more than one dwelling, the push plate on the outside of the building is composed of several buttons, usually one per flat.
Wireless communication devices
Video door phones feature a video installation as well as audio. In these cases, the intercom plate has the same structure as the previous version but features a video monitor connected to a surveillance camera that allows an inspection of the caller.
In situations where wires cannot be run, a wireless system is used. There is a broad spectrum of two-way wireless communication devices that include such devices as handheld radios, outdoor wireless callboxes, as well as traditional desktop devices. The range these units will transmit varies widely based on the wireless technology used.
IP Intercom Systems
When compared to traditional analog intercom systems, IP innovation has allowed for the development of an extensive range of intelligent new features. IP intercoms offer a functionality, whereby visitors’ calls can be re-routed to another line should an individual not be present to allow access to the premises.
For example, a visitor uses the intercom call button, to speak to sales, this rings straight through for sales to let the visitor in. If sales don’t answer within an allotted period, the system can be programmed to ring through to another department. Alternatively, if the user wishes, they can set the system up to allow the visitor to leave a voicemail on the line.
Scalability
Analog systems are often constricted to the number of call stations they can hold on the system
One of the biggest benefits of IP intercom systems is the scalability options they bring. Whether an IP intercom installation requires just one call point or five hundred call points, users can easily expand and add to the system as and when their needs require.
Analog systems are often constricted to the number of call stations they can hold on the system, due to extensive cabling. With an IP intercom system, their solution is more futureproof.
Voice / IP encoding and decoding functions
IP intercom Call Station devices provide voice / IP encoding and decoding functions to allow audio, voice, and control signaling via IP and the network.
Intercom stations’ capability and button assignments can be configured to allow for simple station call functions or to create a group or even all station announcements for essential communications.
Integrated relay/contact switching
Some devices have integrated relay/contact switching to control external devices. As a trigger, these assignments can be made to create simple door access and security system applications.
IP intercom software and apps can also be run on smartphones to provide similar communication and control functions. IP intercom call master devices are typically fewer in number than call stations within any single design, often installed at reception/security desk locations.
Video Intercom Systems
Wireless video intercom allows homeowners and building property owners to provide secure access control
These typically have a unit that has a camera, speaker, and push button that goes at an entrance door, and an internal monitor unit that can communicate with the entrance unit. Some systems can have multiple video monitors internally.
Wireless video intercom allows homeowners and building property owners to provide secure access control to family members and tenants. Motion detection instantly streams video footage to a video monitor or a smartphone depending on which system is chosen.
Two-wire multi-tenant video intercom system
There are numerous features and options to consider when choosing a video intercom monitor for a facility. For example, how many video monitors need serving, the screen size of the available color video monitors, and their auto viewing capabilities.
When a resident/visitor/employee requests entry, the supervisor can unlock the doors using a button on the monitor from a remote location.
Picture memory
Volume control and brightness adjustments can be made from the monitor as well. When using the two-wire multi-tenant video intercom system, the supervisor can even call security from the monitor.
A useful feature on some of the monitors is picture memory. Those with picture memory can save up to a hundred of the last photos taken. The time stamps and dates are saved along with these photos as well.
GSM Intercom Systems
When someone presses the button on the intercom, it dials out on the mobile phone network
GSM stands for Global System for Mobile Communications and is the world’s most popular standard for mobile telephony. To use one of these intercom systems users simply sign up for a service that uses GSM and take a SIM card that they get when they sign up, and place it in a slot inside the intercom control module.
When someone presses the button on the intercom, it dials out on the mobile phone network and places a call to any landline or mobile telephone, no matter where that phone is. As long as there is mobile phone service at the location user wants to place the intercom, then they can place it there.
Multiple dialing
Most of these intercoms can dial multiple telephone numbers until someone answers, so visitors at a door or gate are more likely to reach someone.
The person reached can press a key on their telephone to activate a switch in the intercom that can be used to open a door or gate remotely. Some GSM intercoms enable users to use text messaging to send a message to the intercom to do the same thing.
Pre-program telephone numbers
Another feature of GSM is their ability to pre-program telephone numbers into the system so certain visitors can just call the intercom, and based on their caller line ID, the door or gate will open.
With these intercoms, users can let in family members, who have forgotten their keys
With these intercoms, users can let in family members, who have forgotten their keys or let a delivery person in with instructions on where to leave packages. It also has the advantage that users don’t have to run over to an intercom to answer the door. Users can even use a text message to latch a gate open for parties.
Learn More with APE Fire and Security
The decision as to what type of intercom system is most appropriate will depend on several factors, which include the type of building the system is going to be set up in, the number of users, and the level of security required.
Other factors include whether remote access is desirable or essential and the types of remote control feature that the user would like to have available.