Reference Manual
Rio Rancho, NM
11
DMPA12 Controls and Features
Front Panel
USB Ports
Standard USB connectors are provided on front and
rear panels for setup and control of the DM from a
computer using a Windows Vista, XP or 2000* operating
system.
MODE Switch
The MODE Switch is used for two purposes:
• During power up to switch the unit temporarily from
Slave to Master to enable access with a computer
to make changes in settings
• To set the unit into a Software Update mode for
updating the firmware
If a unit configured to run in a slave mode doesn’t detect
a master unit on power up, it will refuse to boot and
the Status LED will blink rapidly. In this case, pressing
the MODE switch will force the unit to boot up tempo-
rarily as a master to allow settings to be examined or
changed. Cycling the power returns the unit to the slave
mode.
Pressing and holding the MODE switch while power-
ing up the unit places it in Software Update mode. The
Status LED will blink slowly once a firmware update is
initiated, then goes out when the process is completed.
Cycling the power exits the Software Update mode and
returns the unit to normal operation.
Front Panel Gain Controls
The gain of output audio channels is adjustable with
control knobs on the front panel of the DMPA12. This
feature is useful for system setup and adjustment, and
may be left enabled to allow users to “touch up” gains
as needed during operation. Gain can be increased or
decreased within a range which is centered around 0
dB (unity) gain.
The range of adjustment for each channel is individually
programmable using the Control Panel GUI (in Device
Setup Menu) or Lecnet2 serial commands. Changes
made to the gain range settings take effect immediately
and are global in scope - the same settings are in effect
no matter what memory “preset” is loaded. The default
range is 30 dB (+/- 15 dB).
Any or all of the front panel gain controls may be
“locked out” to prevent unauthorized changes to the
system. This is also done using the Control Panel GUI
(in Device Setup Menu) or Lecnet2 serial commands.
Changes made to the gain control lock settings take
effect immediately and are global in scope - the same
settings are in effect no matter what memory “preset” is
loaded.
NOTE: When the Front Panel Mute feature is
enabled, the minimum gain position has a special
meaning. The channel will be muted and the
associated activity indicator will blink RED to
warn the user that no audio is being passed. This
feature can be controlled using the supplied GUI
control panel or the serial command “fpmten.”
Front Panel Output Activity Indicators
These indicators reflect activity on the output audio
channels. Useful for setup and troubleshooting, these
tri-color LEDs are interpreted as follows:
• DARK channel is inactive
• GREEN audio present (level greater than -35
dBu)
• ORANGE output compressor is active
• RED output is in limiting
• BLINKING RED output has been muted using
front panel gain control
• BLINKING ORANGE a fault exists on the output
- check wiring for short circuits, etc.
* Windows Vista, XP and 2000 are trademarks of Microsoft
Corporation
If the STATUS LED
blinks at turn on,
press the MODE
button to change
it to Master status
temporarily.
