Application
Notes for the CircuitWerkes DTMF-16 TouchTone®
Decoder
The
DTMF-16 listens to an audio source (practically
any audio source) and activates its appropriate
output when it hears the matching DTMF tone or
sequence of tones.
All
of the outputs are fully programmable and can
respond to any tone, or sequence of tones (up to
six digits). Four of the outputs are
relays (two are DPDT for switching audio or
other complex circuits). The remaining two
relays are SPST for simple GPI or contact
closures. All relay outputs appear on
captive screw terminals. The remaining 12
outputs are opto-coupled Darlington transistors.
They are capable of operating practically any
computer or logic input. They can be used to
source or sink current (up to 150mA), making
them ideal to drive slave relays or be used in
place of relays in most DC applications.
The
DTMF-16 can operate in one of four possible
modes: momentary, latching (with distinct on and
off codes for each output), momentary after end
of tone or interlocked-latching. In momentary
mode, the output stays on for the duration of
the incoming tone. Latching mode turns a relay
on until the unlatch tone (or tones) are
received. The momentary at end of tone
only activates the output once the tone has
ended. This output is for a fixed
duration. Interlocked-latching mode keeps
the most-recently selected output on until a
different DTMF tone is entered. The units are
shipped from the factory set for momentary
operation but all outputs can be programmed for
any mode via serial terminal.
Here's what some users are
doing with their DTMF-16s:
- Decoding
Automation Tones from radio networks
(connected to satellite receiver) and
interfacing them with your automation system.
- Backup
transmitter control over STL, radio, or
telephone coupler.
- Radio
remote control of camera pan & tilt heads.
- Appliance
/ Computer control over telephone or radio
link.
- Firing
cart decks / digital recorders in studios
(simultaneously muting audio channel) from
remote location.
- Controlling
an attention light at a remote broadcast via
FM subcarrier.
- Electronic
outdoor billboard control via FM subcarrier.
- Parade-Float
control via radio link. Online control of RPU
gear and radio repeaters.
Touch-Tone®
is a registered Trademark of AT&T
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