Weidmuller Wireless Ethernet Modem and Device Server User Manual
9
Rev Version 1.1
Chapter 2 - INSTALLATION
2.1 General
The WI-MOD-xxx-E-5W modules are housed in a rugged aluminum case suitable for DIN rail mounting. The
terminals will accept wires up to 2.5 mm
2
(12 gauge) in size. 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 close to
one another. Following installation, the most common problem is poor communications caused by incorrectly
installed antennas, radio interference on the same channel, or an inadequate radio path. If the radio path is a
problem (the path is too long, or obstructed), a higher performance antenna or a higher mounting point for the
antenna may rectify the problem. Alternatively, use an intermediate WI-MOD-xxx-E-5W module as a repeater.
Each WI-MOD-xxx-E-5W module should be effectively grounded via the
“GND” screw on the back of the module to
ensure that the surge protection circuits inside are effective. The WI-MOD-xxx-E-5W Installation Guide provides
details and an installation drawing appropriate to most applications.
NOTE All connections to the module must be SELV (Safety Extra Low Voltage). Normal 110
–250V
mains supply must not be connected to any terminal of the WI-MOD-xxx-E-5W module. See
“2.3 Power
Supply” on page
14.
2.2 Antenna Installation
The WI-MOD-xxx-E-5W module will operate reliably over large distances, but the achievable distances will vary
with the application, radio configuration, location of antennas, degree of radio interference, and obstructions to
the radio path (such as buildings or trees).
NOTE A WI-MOD-xxx-E-5W module can successfully transmit up to 50 km (31 miles) with a
directional antenna attached.
To achieve the maximum transmission distance, the antennas should be raised above intermediate obstructions so
that 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 that are close to either antenna have a greater blocking
affect than obstructions in the middle of the radio path. The WI-MOD-xxx-E-5W modules provide a diagnostic
feature that displays the radio signal strength of transmissions (see Chapter 5).
Line-of-sight paths are only necessary if you need to achieve the maximum range. Obstructions will reduce the
range, or degrade a reliable path. A larger amount of obstruction can be tolerated for shorter distances, but an
obstructed path requires testing to determine if the path will be reliable. See Chapter 5 for more information on
determining a reliable path.
Where it is not possible to achieve reliable communications between two WI-MOD-xxx-E-5W modules, a third WI-
MOD-xxx-E-5W module may be used to receive the message and re-transmit it. This module is referred to as a
repeater. A repeater module may also have a host device connected to it.
Bench Test and Demo System Setup
Care must be taken with placement of antenna in relation to the radios and the other antennas. Strong radio signals
can saturate the receiver, hindering the overall radio communications. When setting up a bench test, demonstration,
or short range system, the following considerations should be taken into account for optimum radio performance
and reduced signal saturation.
•
Reduce radio transmit power by adjusting the transmit power level on the Radio webpage (see
“4.6 Radio
Configuration” on page 33).
•
If using demo antennas on each end, fit a 20 dB 5W coaxial attenuator in-line with the coaxial cable.
