PS Engineering
PMA450C Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0800
Page 2-7
July 2022
2.5.2
External Marker Lights
For installations that require external marker beacon lights, there are three outputs that can drive 12-Volt
lamps only. The external output lamps are driven high (typ7.0 VDC
4.0 VDC unloaded, at MAX
brightness) when active. Maximum source current per lamp is 125 mA. Voltage varies with photocell dim-
ming.
2.5.3
Middle Marker Sense
A Middle Marker Sense output signal is available from the PMA450C to certain flight control systems. This
function will not operate during the test mode. This output will go to +4.5 VDC (
1.0 VDC) when a valid
Middle Marker signal is received. This output is J1, pin 39.
User Setup Adjustments
**DO NOT MAKE ADJUSTMENTS IN FLIGHT**
Cycling power will remove the audio panel from the user setup menus and back to normal audio panel oper-
ation.
To access the user setup adjustment menus, turn the PMA450C off and then back on. While the
version
screen is displayed, push and hold the bottom line-select button (there is an indicator bar in the display indi-
cating that a menu is available).
This places the unit into the “User Configurable Mode – home screen”. This allows adjustment for:
•
OLED Screen Adjustment
•
Rename Switched Inputs
•
Bluetooth menus
•
Mute mode recall
Note: in this mode, the audio panel functions will be inoperative
2.6.1
Adjust Screen
The first items are adjustments to the OLED, allowing the installer or user to tailor the backlight intensity to
suit the cockpit conditions, and set the time period before the menus revert to the “home” screen.
