Wire the GEA 24 RS-232 port to the PFD or MFD?

[storkeye]

So I have been scouring the Garmin manual and the forums for hours and not come to any solid conclusions on this question.

In my RV-7 I am installing a dual G3X Touch system with G5, GMC 507, GMA 245, GNX 375 and GNC 255. So I have a lot of RS-232 wiring to understand. I've routed almost all of them as per the manual(s) except for the GEA 24 redundant RS-232 data path.

My GSU RS-232 port 1 is wired to the PFD P4601 (pins 4, 5 & 6) as per the recommendations in the manual.

But I cannot find a recommendation for the GEA 24. Should the GEA 24 RS-232 port go to the MFD or the PFD?

Any suggestions would be gratefully received.

 

[mburch]

This depends on how you want to use your displays.

The purpose of the RS-232 connection between a GDU and either a GSU 25 or GEA 24 is to provide a redundant path for ADAHRS or engine data to one GDU, in the unlikely event of a wiring issue that affects CAN bus communication.

If you have two displays, it will be up to you to choose which one you'd prefer to have engine data displayed on in this scenario. The system doesn't care, so it's down to your preference.

 

[g3xpert]

Backup Datapath

So I have been scouring the Garmin manual and the forums for hours and not come to any solid conclusions on this question.

In my RV-7 I am installing a dual G3X Touch system with G5, GMC 507, GMA 245, GNX 375 and GNC 255. So I have a lot of RS-232 wiring to understand. I've routed almost all of them as per the manual(s) except for the GEA 24 redundant RS-232 data path.

My GSU RS-232 port 1 is wired to the PFD P4601 (pins 4, 5 & 6) as per the recommendations in the manual.

But I cannot find a recommendation for the GEA 24. Should the GEA 24 RS-232 port go to the MFD or the PFD?

Any suggestions would be gratefully received.

Good Morning,

A couple of things to consider.

The P4601 connector is pre-configured for Garmin Instrument Data. That format can only be used to establish the backup datapath to either a GSU 25 or GEA 24. It is possible to program one of the 5 configurable serial ports on your display to Garmin Instrument data to establish the backup datapath, but that is one less configurable serial port you have at your disposal when interfacing the Display to the rest of the LRU's in the instrument panel. The P4601 serial port can effectively be thought of as a 6th port on the display, but can only be used for this one purpose. With 2 displays, you have a total of 10 configurable serial ports. It is not uncommon for all of them to be used, so using the P4601 port is generally advantageous.

As a result of connecting the GSU 25 to the P4601 connector of the PFD, and the GEA 24 to the P4601 connector of the MFD, ADAHRS and EIS data will be displayed on separate displays in the event of a CAN failure.

Thanks,

Justin

 

[storkeye]

Thank you

Thank you both,

If I understand it correctly, this choice will only really matter in the event of a CAN bus failure at the same time as a GDU failure. Highly unlikely for both to go at the same time I'd guess.

I'll probably connect it to the MFD because I already have a big enough bundle of wires going to the PFD.