User's Manual

CHAPTER 2

Installation

tion. Some typical examples of the achieved distances, under vari-

ous conditions, are shown in Table 1.

The addIT RTU, however, uses low-power technology and was not

designed to communicate over large distances. The typical “line-

of sight” distance an addIT can communicate is 800 m (approxi-

mately half a mile). This is valid if the partner device is mounted on

a 3 m mast (9 ft) and the addIT is mounted on a 30 cm mast (1 ft).

The above ﬁgures are estimates based on a great deal of experi-

ence with installing this kind of equipment and assume a typical

height of 3 m (9 ft) for the antennas of the remote measuring sta-

tions. Similarly, ideal physical conditions are assumed for the ter-

rain including a ﬂat, open, nonurban environment.

What conclusions can be drawn from Table 1? Primarily, you can

see the importance of having the base station antenna as high as

possible. To gain antenna height, you have several options:

• Build a mast directly on the ground; however, a 30 m (100 ft)

mast may not be a practical option.

• Set up a mast on a tall building (of course, it has to be the

building where you want to have the base station).

• Install the base station in a building that is situated on a hill.

Note that the cable for the outdoor unit delivered with the system

is 30 m long (about 100 ft). This means you must locate your

indoor unit no more than 30 m from the outdoor unit. Lengthening

the cable is not recommended, because the signal strength loss is

signiﬁcant.

Table 1. Communication Between Base Station and

A730MD/A733

Receiving antenna

height

Typical distances

achieved

6 m (18 ft) 5 km (3 miles)

10 m (31 ft) 8 km (5 miles)

20 m (62 ft) 16 km (10 miles)

30 m (92 ft) 24 km (15 miles)