User's Manual

3
Introduction
The WHM900 RF Module is designed to provide designers a hardware solution for
integrating RF wireless data communication applications into different types of
embedded host systems or remote equipment. The WHM900 requires only a serial 3.3 V
TTL interface and antenna to provide wire-less data communications for these systems.
The designer will be required to implement the necessary hardware to host the WHM900
as well as write the software to control the modules wireless link by using the popular AT
command set. The WHM900 is designed to communicate using Radio Frequencies in the
license free ISM bandwidth (900 – 928 MHz). The wireless link operates at speeds up to
76.8Kbps and will reach distances up to 1000 feet depending on the environment and
operational mode. The modules provide 32 user selectable frequencies with 256 different
channel IDs. Frequency hopping with 50 channels and adjustable transmit levels are also
featured. Data error correction and flow control functions are standard. The modules can
be used for point-to-point, point-to-multi-point, or multiple point-to-point wireless
operation. The WHM900 can also be configured to automatically connect and maintain a
continuous wireless using the modules Auto Link option. This document provides all of
the information integrators need to incorporate the Radicom WHM900 RF Module into
their system for state of the art wireless data communication.