UPDATE 2: Apparently there is a size limit, but I haven’t hit it yet. I’m going to make my files 16 bit PCM mono and see if that does the trick.

UPDATE: I installed the audio files tonight, and Tim’s wiring was perfect as usual, and I now get audible warnings. I thought I’d installed my (in my opinion) nicer voice files last night, but I was only getting the “ding” sounds, so maybe there’s a size limit?

GRT updated their HX software in March, and this release finally activated the Audio Output of key warning conditions. This forum posting shows the conditions that are currently supported (listed below). It also says that tones are provided depending on the kind of out-of-boundary condition (see quote below). I never connected my audio wire, since it wasn’t active, but I should have all of the leads on my Approach Fast Stack Hub’s pigtails, so it should be fairly straightforward to get this working. From the EFIS side you just download the Alerts.zip (or here) file from GRT’s website and load them onto a USB, and then to the EFIS, and turn Audio on in the settings.

Most alerts play only once when the condition is first met. There’s a warning tone, a caution tone, and an advisory/chime tone. Most alarms are just the chime. A handful of special alerts are not related to alarms. AoA has a repeating tone that repeats faster the closer you are to stall. Custom voice alerts can be added to any alarm that has an alarm identifier, but those haven’t been documented yet. The only speed alert is for exceeding Vne.

Here’s the list of special alerts:
Min Oil Pressure
Min Fuel Pressure
AoA tone near stall, repeats more frequently closer to stall
Obstacle alarm
New traffic within alert criteria
Autopilot Disconnect
Max Oil Temperature
Low/High Voltage
Max Fuel Flow
Vne Exceeded
Trim alert (from GRT pitch servo) repeats every 30 seconds
SAP height above runway at 500, 200, and 100 feet
Minimums if decision altitude is set
Approaching minimums when 200 feet above decision altitude
Waypoint sequence

Posted By: Brett Ferrell
Thursday May 7th, 2015 at 6:06 PM

Categories: Blog
Tags: Blog

Please Login to Comment.