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3

Theory of Operation

The OTX-900-HH-LR8-PRC Long-Range Handheld Transmitter uses

high performance FSK radio that utilizes a proprietary Frequency Hopping

Spread Spectrum (FHSS) technique and over-the-air protocol. The FHSS

offers much greater noise immunity and range than traditional narrow-band

transmitters.

When a button is pressed on the transmitter, power is applied to the

internal circuitry and the module is enabled. The module detects the logic

states of the button data lines. These states are formatted into a packet

and transmitted repeatedly until the button is released.

The receiving module checks the addressing in the received packet (and

encryption, if enabled). If the packet is valid and intended for the receiver,

then the module replicates the transmitter's button states on its outputs.

These outputs can then be used to activate whatever external circuitry is

required by the application.

product families. Ranges of up to 0.8 mile (1,300m) are possible with good

antennas and a quiet, line-of-sight environment. Applications operating

over shorter distances also benefit from the increased link reliability and

superior noise immunity provided by the radio and protocol.

mixed-mode systems that combine data transmissions with remote control

accept remote control commands from the handheld transmitter as well as

sensor values from other devices in system. This greatly reduces system

cost and complexity and opens up many options for the creative designer.