WSN Manual
Page 4 of 34
Rev. G
– 4 March 2007
2 PRODUCT OVERVIEW
2.1 GENERAL
The WSN Series has been designed as a range of high specification, low cost radio modems for
stand-alone applications or for integration into OEM products.
Through the use of advanced DSP technology, the design has been optimised for reliability and
low current consumption, making the WSN suitable for operation on remote sites without mains
power.
Applications include security, command & control, data logging, SCADA, telemetry, remote
switching or any similar applications where serial data needs to be transmitted.
The WSN is available with three different serial interfaces:-
An RS232 interface with all signalling lines to allow full handshaking if required.
A TTL version of the unit, which uses 5V TTL voltage, levels on the serial interface
connector rather than RS232 signalling levels, but is otherwise the same.
A version with an RS232/RS422/RS485 interface. Required interface mode is selected
using the configuration software. In RS232 mode, the RTS line is looped back to CTS
and the DSR line is looped back to DSR. RS422/RS485 half-duplex (2-wire) or full
duplex (4-wire) modes are both supported.
The data rate on the serial interface can set to a range of values from 150 baud to 38,400 baud,
while the over-air data rate can be independently set to a range of values between 150 baud
and 9,600 baud. If high throughput speeds are not required, the modem can be set to a slower
over-air rate to take advantage of the associated improvement in receiver threshold.
The WSN is available with two different transmit powers. The low power version meets the
licence-exempt ETS300-220 specification while the higher power 5W version meets the tougher
ETS300-113 and the USA and Canadian specifications.
2.2 TRANSMITTER
The transmitter frequency can be user programmed anywhere within it’s pre-aligned bandwidth.
There are two power versions available, 10mW to 750mW and 50mW to 5W. The transmit
power of any particular hardware version can be set accurately within the relevant range under
software control.
2.3 RECEIVER
The receiver is a very low current double conversion superheterodyne with an active balanced
mixer for very good intermodulation performance. Careful attention to spurious response,
adjacent channel and blocking performance, makes the product ideal for crowded telemetry
channels.
To achieve high performance the programmable bandwidth of the receiver has been limited (for
UHF it is 10MHz, + 5MHz from centre frequency), full details are in the technical specification
section.
Should re-alignment be required, the unit can be returned to our service centre.
