Aero Safety Systems AH502 (Annunciator) Connections with HXr

[VELOCITY-XLRG]

Good Day Jeff,

This is a follow-up to our work with beta testing the AeroSafety Systems Annunciator (AH502) with the GRT HXr's (using the Garmin G3X Protocols).

Question:

The AH502 has direct connections with the G3X via these Interconnects:

1. RS232 TX - to AH502 Digital Input 0 (Pin 22)
2. RS232 GND - to AH502 Digital Input 1 (Pin 10)
3. EFIS MASTER WARNING (Pin 44 of G3X)
4. EFIS MASTER CAUTION (Pin 45 of G3X)

Where would #3 (I believe you said there is no Master Caution in HXr) connect to the HXr and with what protocols and baud settings (if the ports you specify need to be set up)?

Also, would #4 (for the AH502) simply go to the same as #3? The AH502 requires it.

Thanks,

Gary E

Attachment is G3X Screenshot of above pins:

Image 1-15-24 at 17.13.jpeg (447.11 KiB) Viewed 26451 times

Image 1-15-24 at 17.14.jpeg (654.43 KiB) Viewed 26450 times

[GRT_Jeff]

1. You need a port that can be configured for 115200 baud and output "G3X Text". Usually this means it has to be on its own port (nothing on the input), however, some things like ADS-B receivers also run at 115200 baud. If you have a 115200 ADS-B input that has no output, you could put the "G3X Text" output on the same port.

2. We don't have a specific RS232 ground. In most cases RS232 grounds don't need to be connected. If the AH502 requires an RS232 GND you can connect it to the AH502's ground.

3. The HXr master warning output is the Warning Light Output connection on Connector B pin 1. The EFIS grounds this pin when any alarm is active. The EFIS flashes the pin (grounds half the time) if there is an unacknowledged alarm.

4. We've never had a caution output or even caution limit settings. On some systems these are the "yellow" limits. We may have them in the future. You could connect this to Discrete Output 1 on Connector B pin 8 for possible future use (or any other Discrete Output if that one is used). Another option is to connect this to the EIS warning light output on EIS main connector pin 7 so that it is activated for low oil pressure even if the HXr is not up and running. It will probably just light up "CAUTION" when the alarm is active. Maybe they already have a separate connection they can use for the EIS though.

[GRT_Jeff]

Edit: I meant Connector B pin 1 for the HXr warning light.

[VELOCITY-XLRG]

Thanks Jeff,

Andrew at AeroSafety Systems asked what voltage is the Warning light pin floating up to when NOT grounded?

Thanks,

Gary Ernest
Velocity XLRG
ARB

[GRT_Jeff]

We don't provide power to the warning light output. It is an Open/Ground output just like the G3X and it can handle over 32V. Normally you would connect a light with power on one end and the other end of the light would go to the EFIS warning light pin so when the EFIS grounds it, the circuit is completed and it lights up.