There are many manufacturers of entry systems, but there are only four main types
1. call button entry (Basically this is a door bell, when called, you either open the gate or look to see who is at the gate before opening).
2.Key entry which can be any mechanical or electronic trigger or device
3. Audio entry, This is a real entry system, where when the door bell is rung, you can talk to the person at the gate from a handset from comfortable position in your property.
4. Video entry, obviously where you can see and talk to the person at the
gate. This comes in full colour and black and white versions.
Nearly as simple as a door bell this can be an inexpensive method of access control.
Lots of options to allow limited entry.
a) Key entry (electronic and or manual)
b) Numeric keypad (electronic and or manual)
c) Sensor, electronic beam
d) Induction loop detector (commonly called Pressure plate)
with all of these options there are many different applications.. click on
this link to see alternatives, accessories
1. call button entry
Allows you to identify who is at the gates before allowing them onto your premises.
As simple as a door bell this is the cheapest and easiest method of access control
3. Audio entry
This is a simple voice link, the visitor at the gate presses a call button and this rings a telephone within the house or building, allowing you to make the decision as to whether you allow access.
4. Video entry
As with Audio, this allows you to hear but also see who is at the gate, giving you more time to decide whether to allow access. This can be Black & White as well as Full colour.