I'm configuring a two-screen G3X with a GTR 200, using the built-in intercom.
Does it matter which GDU provides the aux (warning) audio inputs? Currently I have the audio wired from the MFD (GDU375) but I'm not hearing any audio warnings/alerts. Everything else seems to be working nominally...
Hello James,
Please start by visiting the
SOUND page in config mode. There are multiple parameters there that are important in determining the source of audio alerts, the volume, and over which wires the alert messages/tones are played.
ALERT OUTPUT
This parameter lets you specify whether the alert audio is played over the MONO output or on both the MONO and STEREO outputs.
The ideal way to do this when you are using a GTR 200 is to wire the mono output from pins 1,18 on the GDU 37X to one of the two aux audio inputs on the GTR 200.
If you use the mono alert audio output in this manner, you should set the ALERT OUTPUT field to MONO.
ALERT SOURCE
This parameter lets you specify which display provides the alert audio output signal to the GTR 200. Since you have the GTR 200 connected to your MFD, this field should be set to MFD.
If you have this selection set to AUTO, the alert source prioritization is PFD1, MFD1, PFD2, so the MFD doesn't provide the alert audio unless PFD1 is not available.
One point to consider. Many of us wire the mono alert audio from the PFD instead of the MFD. In the unlikely event of a PFD failure, we might move the MFD display to the PFD1 position at the first opportunity, and we would get our alert audio back by doing this.
ALERT VOLUME and
MESSAGE VOLUME
These parameters determine the audio signal level at the alert audio output on the display. You might start by setting these to 9 or 10 just to make sure there is enough signal to break the squelch on the AUX inputs to the GTR200.
You will also notice that there are AUX1/AUX2 input squelch settings on the GTR 200 that you can also adjust if the alert audio is not breaking squelch.
Finally, notice that at the bottom of the SOUND page on the PFD, there are soft keys that you can press to test the Alert and AOA audio which should make it very easy to troubleshoot your audio installation.
Let us know if you have additional questions.
Thanks,
Steve