Eaton 450U-E Wireless Ethernet Modem and Device Server

The 450U-E Industrial 802.11-based Wireless Ethernet module provides wireless connections between Ethernet

devices and/or Ethernet wired networks (LANs). The 450U-E is a fixed frequency wireless transceiver that operates

within the 360 MHz to 512 MHz frequency spectrum in one of eight 20-MHz frequency bands, depending on the

model purchased.

The 450U-E module provides two serial connections and an Ethernet connection. It is possible to use all three data

connections concurrently, allowing the 450U-E to act as a device server where wireless connections can be made

between serial devices and Ethernet devices. The 450U-E also provides functionality between serial Modbus RTU

devices and Ethernet Modbus TCP devices. Appropriate driver applications will be required in the host devices to

handle other protocols. The modem is capable of passing VLAN tagged frames.

The Ethernet connection is a standard RJ-45 connection that will operate at up to 100 Mbps. The module will

transmit the Ethernet messages on the wireless band at rates between 1 and 19.2 Kbps, depending on model,

band, encryption methods, and radio paths.

1.1 Network Topology

The 450U-E is an Ethernet device, and must be configured as part of an Ethernet network. Each 450U-E module

must be configured as one of the following:

• Access point or client (station)

• Bridge or router

Access Point vs. Client

The 450U-E module that is configured as an access point acts as the wireless master. The access point accepts

and authorizes links initiated by the client modules, and controls the wireless communications. Clients (stations) are

slave modules, and become transparent Ethernet links when connected to the access point.

Figure 1 shows a connection between two Ethernet devices using 450U-E Ethernet modems. In this example, one

450U-E is configured as an access point and the other as a client.

The 450U-E modules are housed in a rugged aluminum case suitable for DIN rail mounting. The terminals will

accept wires up to 2.5 mm2 (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 450U-E module as a repeater.

Each 450U-E 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 450U-E Installation Guide provides details and an installation

drawing appropriate to most applications.

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.

• Antennas must be kept a suitable distance from each other. Check the receive signal strength on the

Connectivity page of the module and ensure that the level is not greater than –45 dB.

Directional Antennas

A directional antenna provides high gain in the forward direction, but lower gain in other directions. This type of

antenna may be used to compensate for coaxial cable loss for installations with marginal radio path. Directional

antennas can be any of the following:

• Yagi antenna with a main beam and orthogonal elements

• Directional radome, which is cylindrical in shape

• Parabolic antenna

Yagi antennas should be installed with the main beam horizontal, pointing in the forward direction. If the Yagi

antenna is transmitting to a vertically mounted omni-directional antenna, the Yagi elements should be vertical. If

the Yagi is transmitting to another Yagi, the elements at each end of the wireless link need to be in the same plane

(horizontal or vertical).

Directional radomes should be installed with the central beam horizontal, and must be pointed exactly in the

direction of transmission to benefit from the gain of the antenna.

Parabolic antennas should be mounted according to the manufacturer’s instructions, with the parabolic grid at the

back and the radiating element pointing in the direction of the transmission.