Page 49 - DCAP311_DCAP607_WIRELESS_NETWORKS

Unit 3: Radio Frequency and Light Signal Fundamentals

The most common link size is 1m. There are also infrared transceivers with link size as low as Notes
875 nm or as high as 6.5m. The maximum idle current available is 10A, with the most common
infrared transceiver chips having a maximum idle current of 10 mA.
IR transceivers are generally used in communications applications, although they also have other
applications as well. In communications, infrared transceivers can often be used in order to synch
devices.

Example: A PDA can be synched with a PC through the use of infrared transceivers in
both devices. The systems can send data back and forth to synchronize their contents.
IR transceivers can also be used for entering and collecting data in the field. By using a handheld
IR transceiver, a researcher can collect data on his portable device and then send it to a PC by
using an infrared transceiver. The transceiver can also receive software upgrades, therefore
keeping it up to date with the rest of the equipment in the laboratory or the plant.

3.1.1 Digi Wireless Transceiver Modules

The TRX900 is an encrypted digital wireless transmitter with optional internal backup recording
and IFB. By incorporating an IFB receiver into the body of a traditional wireless transmitter, both
functions are now combined in a package smaller than most transmitters on the market today.
z z Fully encrypted audio transmission
z z Built-in 2.4 GHz receiver to receive timecode and remote control signals from ZaxNet and/
or IFB100

z z Digital modulation wireless transmitter
z z Superb audio quality that rivals a mic cable
z z Digital drop-out protection
z z 5 hour run time on single CR123 battery
z z Graphic LCD display
z z Integrated timecode reception
z z Small and lightweight
z z No inter-modulation – up to 50 transmitters, in the same frequency block, can be used
together.

z z Built-in IFB audio receiver
z z 96 hour internal backup recording with timecode stamp
The TRX900AA’s 96 hour, 24 bit internal loop-recording option is perfect for those times when
there’s a lack of available frequencies or when drop-outs cannot be tolerated. The audio is
timecode referenced, recorded on and played back from a removable MicroSD memory card that
can be used in any standard SD card reader.
Audio can be recorded, played back and timecode referenced either manually or through remote
control commands from the IFB100 transmitter.
The audio is automatically recorded full bandwidth as a .ZAX file. The included ZaxConvert file
transfer software (available for both MAC and PC) utilizes sample rate conversion to obtain the
sample rate and bit depth of choice when files are imported to your computer. There are two
timecode stamped file types to choose from: BWF (Broadcast Wave Format) or MP3 (MPEG-1
Audio Layer 3). MP3 files are great for quickly transferring files over the internet to a transcription
house. Any number of versions of the same recording can be made from a single file.

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