User manual

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Cooper Bussmann 245U-E Wireless Ethernet Modem & Device Server User Manual
Rev Version 2.19
ChapTEr 2 - INSTaLLaTION
2.0 General
The 245U-E modules are housed in a rugged aluminum case suitable for DIN-rail mounting. Terminals will accept
wires up to 2.5 mm
2
(12 gauge) in size. All connections to the module must be SELV (Safety Extra Low Voltage).
Normal 110-250 V mains supply must not be connected to any terminal of the 245U-E module. See “2.2 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 (for example, 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 245U-E module as a repeater.
The 245U-E Installation Guide provides an installation drawing appropriate to most applications. Further information
is provided below. Each 245U-E module should be effectively earthed via the “GND” terminal on the back of the
module. This is to ensure that the surge protection circuits inside are effective.
2.1 Antenna Installation
The 245U-E module will operate reliably over large distances. However, the achievable distances will vary with the
application, radio model, 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 radio model, the regulated RF power permitted in your country,
and whether you use separate transmit and receive antennas. If using a 245U-E-G (2.4 GHz) with a single antenna,
10 km (6 miles) can be achieved in USA, Canada, and Australia (4 W EIRP) and 2 km in Europe (100 mW EIRP).
Ifusing a 245U-E-A (5 GHz) with a single antenna, 5 km (3 miles) can be achieved in USA, Canada, and Australia
(1 W EIRP) and 3 km in Europe (500 mW EIRP), but more care is needed in selecting antennas and coax, and radio
paths need to be complete line of site (no obstruction whatsoever).
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 will have more of a
blocking affect than obstructions in the middle of the radio path. The 245U-E modules provide a diagnostic feature
that displays the radio signal strength of transmissions (refer to “Chapter 4 - DIAGNOSTICS”).
Line-of-sight paths are only necessary to obtain the maximum range. Obstructions will reduce the range, but
may not prevent a reliable path. A greater amount of obstruction can be tolerated for shorter distances. For short
distances, it is possible to mount the antennas inside buildings. An obstructed path requires testing to determine if
the path will be reliable. Refer to “4.7 Testing Radio Paths.”
Where it is not possible to achieve reliable communications between two 245U-E modules, a third 245U-E module
may be used to receive the message and re-transmit it. This module is referred to as a repeater. This module may
also have a host device connected to it.
The 245U-E unit has two antenna connections at the top of the module, allowing for two antennas to be fitted
to the module if necessary. By default the right connector, labeled “TX/RX,” is the main connection used for
transmitter and receiver. The left connector, labeled “RX,” is not connected unless configured as described in
“3.10 Advanced Radio Configuration.” Each antenna port can be configured for TX only, RX only, or Diversity
(TXand RX). Selection can be made by choosing one of the options from TX Antenna / RX Antenna on the
Advanced Radio Configuration page.
NOTE When only one antenna is used, it must be connected to the TX/RX connector.