Cooper Bussmann BU-945U-E 802.11 DSSS Power Supply, Serial Connections, Directional Antennas

Cooper Bussmann Wireless Ethernet & Device Server BU-945U-E 802.11 DSSS User Manual

Directional Antennas

Directional antennas can be a:

•Yagi antenna with a main beam and orthogonal elements

•Directional radome, which is cylindrical in shape

•Parabolic antenna

A directional antenna provides high gain in the forward direction, but lower gain in other directions. This may be used to compensate for coaxial cable loss for installations with marginal radio path.

Yagi antennas should be installed with the main beam horizontal, pointing in the forward direction. If the Yagi is transmitting to a vertically mounted omni-directional antenna, then the Yagi elements should be vertical. If the Yagi is transmitting to another Yagi, then the elements at each end of the wireless link need to 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 as per the manufacturer’s instructions, with the parabolic grid at the “back” and the radiating element pointing in the direction of the transmission.

Ensure that the antenna mounting bracket is well connected to “ground/earth.”

2.3 Power Supply

The BU-945U-E module can be powered from a 9-30Vdc power supply. The power supply should be rated at 1 Amp minimum. The positive side of the supply must not be connected to earth. The supply negative is connected to the unit case internally. The DC supply may be a floating supply or negatively grounded.

The power requirements of the BU-945U-E unit are shown in the following table

	12Vdc	24Vdc
Quiescent	300mA	160mA
TX @100mW	370mA	190mA
TX @ 400mW	410mA	210mA

A Ground Terminal is provided on the back of the module. This Terminal should be connected to the Main Ground point of the installation in order to provide efficient surge protection for the module (refer to the Installation Diagram)

2.4 Serial Connections

RS232 Serial Port

The serial port is a 9 pin DB9 female and provides for connection to a host device as well as a PC terminal for configuration, field testing and for factory testing. Communication is via standard RS232 signals. The BU-945U-E is configured as DCE equipment with the pinouts detailed below.

Hardware handshaking using the CTS/RTS lines is provided. The CTS/RTS lines may be used to reflect the status of the local unit’s input buffer. The BU-945U-E does not support XON/XOFF.

Example cable drawings for connection to a DTE host (a PC) or another DCE hosts (or modem) are detailed to the right.

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