User's Manual

MHX-920 Operating Manual: Chapter2 General 1
2. General
2.0 Product Overview
The MHX920 is a high-performance embedded wireless data transceiver.
Operating in the 902 - 928 MHz ISM band, this frequency-hopping spread-
spectrum module is capable of providing reliable wireless data transfer
between almost any type of equipment which uses an asynchronous serial
interface. The small-size and superior RF performance of this module make
it ideal for many applications.
While a pair of MHX920 modules can link two terminal devices (“point-to-
point” operation); multiple modules can be used together to create a
network of various topologies, including “point-to-multipoint” and
“repeater” operation. Multiple independent networks can operate
concurrently, so it is possible for unrelated communications to take place in
the same or a nearby area without sacrificing privacy or reliability.
1.1 Features
Key features of the MHX920 include:
 transmission within a public, license-exempt band of the radio
spectrum
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– this means that it can be used without access fees
(such as those incurred by cellular airtime).
 a serial I/O data port with handshaking and hardware flow
control, allowing the MHX920 to interface directly to any
equipment with an asynchronous serial interface.
 ease of installation and use – the MHX920 module uses a
subset of standard AT style commands, very similar to those
used by traditional telephone line modems.
 all units in a system are physically identical, and can be
configured as a master, repeater or slave using the AT
command set. No hardware modifications are required
 128 sets of user-selectable pseudo-random hopping patterns,
intelligently designed to offer the possibility of separately
operating multiple networks while providing security,
reliability and high tolerance to interference.
 encryption key with 65536 user-selectable values to maximize
security and privacy of communications.
 32-bit of CRC error detection and auto re-transmit to provide
accuracy and reliability of data.
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902-928 MHz, which is license-free within North America; may need to be factory-
configured differently for some countries.