Model 240 Passenger Speaker Amplifier
SM240 Installation and Operation Manual
Section 2 Rev: 1.01
Issue
4 Page
2-3
ENG-FORM: 805-0121.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
2.4.5 Mode
Selection
The operating modes of the Model 240 are established when either a ground (low) signal or a 12 to 32
Vdc (high) signal is applied to the relevant pin of the 37 pin connector as listed below:
Pin No. Control
Signal
Identification Function
P50-16
Low
ADF 1 Switch
Connects ADF 1 input audio to Left and Right Speaker outputs.
P50-15
Low
ADF 2 Switch
Connects ADF 2 input audio to Left and Right Speaker outputs.
P50-14 Low
PSC
Switch Connects Pilot Select COMM input audio to Left and Right
Speaker outputs.
P50-13
Low
TV Switch
Connects TV input audio to Left and Right Speaker outputs.
P50-5 Low
Stereo
Switch
Connects Stereo Left and Right Input audio to Left and Right
Speaker outputs, respectively.
P50-24
Low
PA Key
PSC, TV and Stereo input audio circuits.
P50-25 Low
Briefer
Switch
Connects Briefer input audio to PA Sidetone and Left and Right
Speaker outputs. Opens ADF, PSC, TV and Stereo input audio circuits.
P50-31
*High
No Smoking
Chime tone to Left and Right Stereo outputs.
P50-32
*High
Seat Belt
Chime tone to Left and Right Stereo outputs.
P50-33
Low
Cabin Call
Ringer tone to Left and Right Stereo outputs.
P50-34
Low
Hook Switch
Disables ringer tone.
* An application or removal of a High signal at pins P50-31 and P50-32 will provide a chime tone at Left
and Right speaker outputs.
2.4.6
Numerical Pin Identification
Pin Identification, P40 (25 pin connector):
1.
Left Spkr Out Hi
14.
Left Spkr Out Hi
2.
Left Spkr Out Hi
15.
No Connection
3.
Left Spkr Out Lo
16.
No Connection
4.
Left Spkr Out Lo
17
No Connection
5.
Left Spkr Out Lo
18.
Power Ground
6.
28 VDC
19.
Power Ground
7.
28 VDC
20.
Power Ground
8.
28 VDC
21.
No Connection
9.
Right Spkr Out Lo
22.
Chassis Ground
10.
Right Spkr Out Lo
23.
No Connection
11
Right Spkr Out Lo
24.
No Connection
12.
Right Spkr Out Hi
25.
Right Spkr Out Hi
13.
Right Spkr Out Hi
