Gewiss Chorus Digital Vision, Техническое руководство

Страница: 21 / 104

Chorus Digital Vision - Technical System Manual
19
DESIGN
To facilitate the calculation of the number of devices needed, you can fill in a table like the one below:
Notes for compilation
1. Only fill in the lines corresponding to the number of front door units you want to install.
2. There must be at least one primary front door unit in the system.
3. If the front door unit is on the street, the number of apartments is the total number of the entire structure.
4.
If the front door unit is at the entrance to the staircase or single building, the number of apartments is the number in that staircase or building.
5. The number of apartment units must be clearly indicated for staircases/buildings in the relative line (if the system only has a front
door unit on the street, it must be indicated in this line only); the number of apartment units cannot be higher than 4 times the num-
ber of the respective apartments.
6. The total number of relay units in the entire system must not exceed 4.
7. The total number of camera interfaces in the entire system must not exceed 4.
Determining the necessary number of switches
Below there is an explanation of how to calculate the minimum number of switches needed in the system. The real number of switches
may be higher, and will have to be defined by examining and checking the wiring requirements and the physical distribution of the buil-
dings, apartments, apartment units, relay units and camera interfaces.
To calculate the minimum number of switches, proceed as follows:
t
In the case of a single front door unit, add together the number of apartment units, the number of relay units, and the number of
camera interfaces. Divide the total by 4, rounding up if necessary.
Example : a building with 4 apartments, each with an apartment unit, a camera interface and a relay unit. The switch calculation
is therefore:
4 apartment units + 1 relay unit + 1 camera interface = 6 connections
6 connections ÷ 4 = 1.5 switches
rounding up, this means 2 switches.
t
In the case of several front door units, add together - for each staircase or building - the number of apartment units, the number of
relay units, and the number of camera interfaces. Divide the total by 4, rounding up if necessary (as in the previous example). Then
divide the number of front door units by 2 and round up again.
Example : a block of flats with a main entrance from the street and two separate internal buildings, one with 15 apartment units
on 7 apartments and the other with 12 apartment units on 6 apartments. A single front door unit at the entrance from
the street, and a separate front door unit for each building entrance. The switch calculation is therefore:
15 apartment units (connections) ÷ 4 = 3.75 (which, rounded up, means 4 switches for the first building)
12 apartment units (connections) ÷ 4 = 3 switches for the second building
3 front door units ÷ 2 = 1,5 (which, rounded up, means 2 switches).
The overall requirement is therefore 4 + 3 + 2 = 9 switches
Front door
unit
Primary
(on the street)
Secondary
(at the entrance
to the staircase/
building)
No. of
apartments
Total apartment
units
No. of
relay units
No. of camera
interfaces
1
† †
2
† †
3
† †
4
† †
5
† †
6
† †
7
† †
8
† †