User manual

Chapter 3 Installation
Page 27 ©February 2009
Chapter 3 Installation
3.1 General
The 105G module is housed in a rugged aluminum case, suitable for DIN-rail mounting.
Terminals will accept wires up to 2.5 sqmm in size.
All connections to the module must be low voltage (SELV). Normal 110-240V mains
supply should not be connected to any terminal of the 105G module. Refer to Section 3.3
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 aerials, or radio
interference on the same channel, or the radio path being inadequate. If the radio path is a
problem (i.e. path too long, or obstructions in the way), then higher performance aerials or a
higher mounting point for the aerial may rectify the problem. Alternately, use an intermediate
105U Module as a repeater.
The foldout sheet 105G Installation Guide provides an installation drawing appropriate to most
applications. Further information is detailed below.
Each 105G module should be effectively earthed /grounded via the "GND" terminal on the 105U
module - this is to ensure that the surge protection circuits inside the module are effective.
3.2 Antenna Installation
The 105U modules 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 hills or trees) to the radio path.
Please refer to your distributor for the expected maximum distance to comply with local radio
regulations. Where it is not possible to achieve reliable communications between two 105
modules, then a third 105 module may be used to receive the message and retransmit it. This
module is referred to as a repeater. This module may also have input/output (I/O) signals
connected to it and form part of the I/O network – refer to Chapter 4Configuration of this
manual.
An antenna must be connected to each 105 module using the coaxial female connector which
protrudes though one of the end plates.
To achieve the maximum transmission distance, the antennas should be raised above
intermediate obstructions so the radio path is true “line of sight”. Because of the curvature of the
earth, the antennas will need to be elevated at least 5 metres above ground for paths greater than
5 km. The modules will operate reliably with some obstruction of the radio path, although the
reliable distance will be reduced. Obstructions that are close to either antenna will have more of
a blocking effect than obstructions in the middle of the radio path. For example, a group of trees
around the antenna is a larger obstruction than a group of trees further away from the antenna.
The 105G modules provide a test feature that displays the radio signal strength.