Page Type: REFERENCE
A "VOX sender" is the Rangecast feed site software operating in a special mode used for bringing audio content into Rangecast from any audio source other than a Uniden radio scanner that supports data communications with a PC. Examples include audio streams obtained from the internet, microphones, radio scanners that lack the ability to communicate with a PC, or non-Uniden radio scanners (the software only knows how to communicate with Uniden scanners). In addition, VOX is sometimes used temporarily for technical analysis of audio from a radio scanner normally used in non-VOX mode.
The VOX mode of operation differs from the normal mode in several important ways, so there are numerous places in the FAQ where the exception "... unless this is a VOX sender" must be written. However, most customers will have no idea what a VOX sender is (or whether they are dealing with one), so it is important to provide some background.
It is useful to know that VOX senders are extremely rare. If you don't know what a VOX sender is, or whether you are dealing with one -- it's very probable that there is no VOX sender involved at your site.
WHEN IS VOX USED?
Nearly all feed sites bring audio into the Rangecast system from Uniden radio scanners that support data communications with a PC. This includes Uniden models 15, 15X, 996, 996T, 996XT, and 536HP. The Rangecast feed site software, when supporting these radio scanners, is NOT operated in VOX mode.
VOX mode is only used in these special cases:
* Receiving audio from an internet audio stream
* Receiving audio from a microphone
* Receiving audio from a scanner that is not from the Uniden product line
* Receiving audio from a Uniden scanner that lacks the ability to communicate with a PC
* Receiving audio from a scanner without use of a data cable connecting scanner/PC
In addition, the VOX mode may be used temporarily during certain technical tests, when evaluating the performance of the scanner.
HOW DOES VOX DIFFER FROM NORMAL OPERATIONS?
The key distinction is how the Rangecast software knows when each transmission begins and ends -- that is, how the continuous stream of incoming audio is chopped into separate recordings for each transmission.
* In normal (non-VOX) mode, the Rangecast software is in data communication with a Uniden radio scanner, which tells the PC when transmissions start and end. The software uses this information to know when to start and stop recording each transmission.
* In VOX mode, the Rangecast software listens to the audio line to chop the audio into separate transmissions. When silence is broken, recording begins; when silence returns, recording ends. This is conceptually similar to the operation of some "voice operated' (VOX) devices, such as speakerphones, radio transmitters, etc.
HOW DOES VOX MODE AFFECT THE MAINTENANCE OF RANGECAST SOFTWARE?
In the normal (non-VOX) mode of operation, the Rangecast sender software expects to be in data communication with a compatible Uniden radio scanner. Therefore, the normal operation involves detecting and staying in communication with such a scanner.
In VOX mode, the software does not attempt to establish data communications with external hardware, and the only connection is an audio input line.
Since nearly all Rangecast audio sources are the non-VOX variety, it is convenient to write instructions for feed site setup, operation, and maintenance with the assumption that the software is operating in normal (non-VOX) mode and must be associated with external physical hardware. None of this applies to a VOX sender, so whenever these steps are encountered, there is a note that the step does not apply to VOX senders.