Chapter Two
Installation
Page 9 November
2008
Chapter Two
INSTALLATION
2.1
General
The D2 W MDME 2400 module is housed in a rugged aluminium case, suitable for DIN rail
mounting. Terminals will accept wires up to 2.5 sqmm (12 gauge) in size.
All connections to the module must be SELV. Normal 110-250V mains supply should not
be connected to any terminal of the D2 W MDME 2400 module.
Refer to Section 2.3,
“
Power Supply
.”
Before installing a new system, it is preferable to bench test the complete system. Configuration
problems are easier to recognize when the system units are adjacent. Following installation, the
most common problem is poor communications caused by incorrectly installed antennas, radio
interference on the same channel, or the radio path being inadequate. If the radio path is a
problem (i.e. path is too long or obstructions are in the way), then higher performance antennas
or a higher mounting point for the antenna may rectify the problem. Alternatively, use an
intermediate D2 W MDME 2400 module as a repeater.
The foldout sheet D2 W MDME 2400
Installation Guide
provides an installation drawing
appropriate to most applications. Further information is detailed below.
Each D2 W MDME 2400 module should be effectively earthed via the "GND" terminal on the
D2 W MDME 2400 module - this is to ensure that the surge protection circuits inside the D2 W
MDME 2400 module are effective.
2.2 Antenna
Installation
The D2 W MDME 2400 module will operate reliably over large distances. The distance which
may be reliably achieved will vary with each application - depending on the type and location of
antennas, the degree of radio interference, and obstructions (such as buildings or trees) to the
radio path.
The maximum range achievable depends on the regulated RF power permitted in your country,
and whether you use separate transmit and receive antennas. With a single antenna, 5 km (3
miles) can be achieved in the U.S., Canada, and Australia (4W ERP), and 1 km in Europe
(100mW ERP). With separate transmit and receive antennas, more than 10 km (6 miles) can be
achieved in the U.S., Canada, and Australia, and more than 5 km in Europe.
To achieve the maximum transmission distance, the antennas should be raised above
intermediate obstructions so the radio path is true “line-of-sight.” The modules will operate
reliably with some obstruction of the radio path, although the reliable distance will be reduced.
Obstructions which are close to either antenna will have more of a blocking effect than
obstructions in the middle of the radio path. The D2 W MDME 2400 modules provide a
diagnostic feature which displays the radio signal strength of transmissions (refer to the
Diagnostics
section for more information).
