Murata Electronics North America 2492 Manual Do Utilizador
WIT2492
2000- 2007 Cirronet
1
M-2492-0000 Rev G1
1. INTRODUCTION
The WIT2492 radio transceiver provides reliable wireless connectivity for either point-
to-point or multipoint applications. Frequency hopping spread spectrum
technology ensures maximum resistance to noise and multipath fading and robustness in
the presence of interfering signals, while operation in the 2.4GHz ISM band allows
license-free use and worldwide compliance. A simple serial interface supports
asynchronous data up to 230400 bps. An on-board 3 KB buffer and an error-correcting
over-the-air protocol provide smooth data flow and simplify the task of integration with
existing applications.
to-point or multipoint applications. Frequency hopping spread spectrum
technology ensures maximum resistance to noise and multipath fading and robustness in
the presence of interfering signals, while operation in the 2.4GHz ISM band allows
license-free use and worldwide compliance. A simple serial interface supports
asynchronous data up to 230400 bps. An on-board 3 KB buffer and an error-correcting
over-the-air protocol provide smooth data flow and simplify the task of integration with
existing applications.
- Frequency hopping technology
with 43 frequency channels
(2400-2483.5 MHz).
(2400-2483.5 MHz).
- Supports point-to-point or
multipoint applications.
- Meets FCC rules DTS and ETS
300.328 for worldwide license-
free operation.
free operation.
- Superior range to 802.11 wireless
LAN devices.
- Transparent ARQ protocol
w/3KB buffer ensures data
integrity.
integrity.
- Digital addressing supports up to
64 networks, with 62 remotes per
network.
network.
- Low power 3.3v CMOS signals
- Simple serial interface handles
both data and control at up to
230400 bps.
230400 bps.
- Fast acquisition typically locks
to hopping pattern in 2 seconds
or less.
or less.
- Selectable 10 mW or 100 mW
transmit power.
- Built-in data scrambling reduces
possibility of eavesdropping.
- Nonvolatile memory stores
configuration when powered
off.
off.
- Smart power management
features for low current
consumption.
consumption.
- Dynamic TDMA slot
assignment that maximizes
throughput.
throughput.
1.1. Why Spread Spectrum?
The radio transmission channel is very hostile, corrupted by noise, path loss and
interfering transmissions from other radios. Even in a pure interference-free
environment, radio performance faces serious degradation through a phenomenon
known as multipath fading. Multipath fading results when two or more reflected
rays of the transmitted signal arrive at the receiving antenna with opposing phase,
thereby partially or completely canceling the desired signal. This is a problem
particularly prevalent in indoor installations. In the frequency domain, a multipath
fade can be described as a frequency-selective notch that shifts in location and
interfering transmissions from other radios. Even in a pure interference-free
environment, radio performance faces serious degradation through a phenomenon
known as multipath fading. Multipath fading results when two or more reflected
rays of the transmitted signal arrive at the receiving antenna with opposing phase,
thereby partially or completely canceling the desired signal. This is a problem
particularly prevalent in indoor installations. In the frequency domain, a multipath
fade can be described as a frequency-selective notch that shifts in location and