User`s manual

Page 8
3.1.4.5 Clear Filters
Use the CLEAR button to clear the solution of all adaptive filters.
3.1.5 Lock/Unlock Unit
As marked on the front panel, the BW and nCH select buttons can be used to
lock the filter controls. To LOCK or UNLOCK the unit, hold these buttons down
together for three seconds; the MEM/LOCK LED in the upper right corner of the
front panel will turn on or off to indicate when the state has changed. The LED is
on when the unit is locked and off when the unit is unlocked.
When the unit is locked, the FILTER CONTROLS section of the front panel is
disabled. These controls include the MONO/STEREO selector, the BW and nCH
selectors, the AGC and HPF enable/disable buttons, and the CLEAR button.
Pressing these buttons will have no effect when the unit is locked. The EXT FRZ
(external freeze) and EXT CLR (external clear) switch-closure connectors on the
rear panel are also disabled and have no effect when the unit is locked.
The INPUT LEVELS, INPUT SELECT, and headphone controls remain active
even when the unit is locked.
When the user unlocks the MicroDAC 5, it will keep running at the locked
settings, except that the current state of the AGC and HPF buttons will be
applied. For example, if you lock the unit with the AGC button “in” (enabled),
then toggle the AGC button to the OUT position (disabled) while the unit is
locked, then unlock the unit, the AGC will automatically be disabled when the unit
is unlocked. This guarantees that when the unit is unlocked, the filtering
behavior and the front panel controls are always in agreement.
3.2 Rear Panel
Two connectors on the back panel (EXT CLR and EXT FRZ) can be used to
connect external switches for additional filter controls.
3.2.1 External Clear Switch
An external pushbutton switch wired to the EXT CLR connector can be used to
remotely clear the filter solution. Function is identical to the CLEAR switch on the
front panel; when the button is pressed, the filters are cleared.
3.2.2 External Freeze Switch
An external switch (slide or toggle switch recommended) wired to the EXT FRZ
switch can be used to freeze the adaptive filters. When the switch is closed, the
filters are frozen; when open, the filters are adapting. When the filters are frozen,
the ADAPT LED on the front panel goes out.