PS Engineering
PMA450B Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0600
Page 3-1
Rev. 5, August 2020
Timer Functions
The PMA450B contains a timer function with count down, or count up functions. This can be used as a
convenient reminder for timed instrument approaches, fuel tank switching, flight elapsed time, etc. The
Timer is accessed from the main menu, bottom button.
3.16.1 Setting the timer
Press the SET button and use adjust the desired time using the outer knob for minutes, and the inner knob for
seconds, up to 99:99.
3.16.2 Count Down
Press Start to begin counting down.
The display reverts to normal after a few seconds. Then as the countdown progresses, the display will mo-
mentarily show remaining time as the interval is divided in half (from 1 minute, then 30 seconds, then 15
seconds, etc.). At one-minute remaining, an audio alert says “One Minute.” The display shows remaining
time at 10 seconds, and audio alert says “Time Expired.”
The set time is remembered until changes, and can be reset to the last value.
3.16.3 Count up
The count up timer simply shows elapsed time since START, and counts to 99 minutes, 99 seconds. Count
up will stay on the screen until manually stopped.
User Setup menus
The PMA450B has several user adjustable functions accessible from a setup menu.
Figure 3-10 User Configuration Menu
During the unit boot up process, press the lower line select button until the setup screen appears.
Cycle the PMA450B power to exit setup screen.
MINUTES
SECONDS
