Fire Suppression Panel

Fire Suppression Panel

Interfacing the panel

This was a relatively simple task. Since pmSystems already supports all the actions it was only a matter of connecting the switches and annunciators to the appropriate pmSystems offsets. I am doing this using a Phidgets 8/8/8 and Phidgets LED64 card that also use for the WXR panel.

Connection diagram

The table below shows how the fire suppression panel is connected to the Phidgets boards. Note that some of the inputs and outputs are used for the WXR panel.

Phidgets 8/8/8

Phidgets LED64

Analog Input		Digital Input
2	Fire/Fault Test	2	Bell Cut-out
3	Extinguisher Test
4	Eng 1 Fire Handle
5	APU Fire Handle
6	Eng 2 Fire Handle

LED Output
0	Eng 1 Overheat	8	Eng 1 Fire Handle
1	Eng 2 Overheat	9	APU Fire Handle
2	Wheel Well	10	Eng 2 Fire Handle
3	Fault	11	Ext Test APU
4	APU Det INOP	12	Ext Test R
5	APU Bottle Discharge	13	Ext Test L
6	L Bottle Discharge	59	Back light
7	R Bottle Discharge	60	Back light
		61	Back light

Switch wiring

The diagram on the left shows the wiring for a Fire Handle selector (4 positions).
The diagram on the right is for the two test switches. These are FAULT/INOP, OVHT/FIRE and EXT TEST.

Although I am using 1.2 kΩ resistors, their value is not critical as long as they are the same and not too low as they draw current from the Phidgets reference supply.

Fire Bell

When a fire alarm occurs an alarm bell sounds. The PMDG 737NG has a wave file for that that I integrated in pmSounds. In my system it's at D:\Program Files\Microsoft Games\Flight Simulator 9\Sound\Pmdg\737tng\PMDG_fire_bell.wav. I copied the file to the Sound folder in pmSounds and renamed it to: firebell.wav. Then I added to pmSounds.cfg:

File=firebell.wav
Type=main
Disabled=Off
Volume=default

and to SoundList.txt:

firebell,5649,.0,1,CYC

Software

The stand-alone VB.NET program that I have written for the WXR panel, also interfaces the Fire Suppression Panel. It continuously monitors the switches and sends commands to pmSystems through FSUIPC messages. In addition, it reads the appropriate FSUIPC values and sets to the outputs of the LED64 card to activate the annunciators.

For more information about the software see the panel_console software page. If you have any questions or remarks please send me an e-mail at: pvrijald@planet.nl.

Fire Suppression Panel with fire alarm in engine 1

Overheat warning in engine 2

Back Lighting

Using epoxy glue, I fixed Christmas tree light (yellow LED) to the appropriate places on the metal support panel. I first put transparent tape over the lighting holes, so theoretically the front panel can still be detached from the metal support panel.

I am using the lights in groups of 10, so each LED64 output drives 10 LEDs in parallel, which gives enough light.

Testing the system

The two test switches are fully operational. To create an overheat or file condition in flight or on the ground I have the extended my "GroundControl" program to do exactly that. It's included in the panel_console package.

Currently there are two problems with the pmSystems part of the fire panel. These are:

1) The Fire Warn/Bell Cutout on the glare shield does not silence the fire bell
2) A wheel well fire and APU fire falsely turn on the OVHT and Master Caution on the glare shield