AXIS Databus Architecture Help / RS-232 Datatypes

[TASEsq]

Hi Brains Trust,

I know the AXIS system and manuals are new, but i also know there are people much smarter than me on here! @g3xpert

Attached is my proposed data-bus architecture for a 2 screen GDU116B system with:
GNX375
GNX215 Com1 / Nav 1
GTR205 Com 2
+ All the other usual Garmin Boxes.

I would appreciate if anyone sees any issues or errors please let me know! (or any suggestions for redundancy improvement).

The question:
Do i need the GAD29?

The GNX375 is providing NAV information via HSDB to the GDU116 PFD (which shares it to everywhere else on the bus). Presumably this would then supply this on the CANBUS to the G5? The ARINC acts a a backup in case the HSDB fails and puts the NAV info onto the CANBUS which can then go to the G5 and to GDU's etc.

However, could I not delete the GAD29 (and save $1000) and use a seperate RS-232 connections from the GNX375 direct to the G5, and antother to each of the GDU116's? (there are plenty of RS-232 ports left).

Similarly, the ARINC on the GNC215 gives a backup VHF nav data path for the G5. But i already have BOTH HSDB and CANBUS? Is this really needed?


The other question:
I can't seem to find the data format types needed for the RS-232 backup connections from the GSU25 and the GEA24 to the main screens? In the G3X manual they were listed on the interconnect diagrams. In the AXIS manual they are generally in Appendix C, but they don't list these LRU's.

Do i just assume they are the same as the G3X? (aka they are all "Garmin Instrument Data").

Thanks for the help!

 

[lr172]

The GNX375 is providing NAV information via HSDB to the GDU116 PFD (which shares it to everywhere else on the bus). Presumably this would then supply this on the CANBUS to the G5? The ARINC acts a a backup in case the HSDB fails and puts the NAV info onto the CANBUS which can then go to the G5 and to GDU's etc.

However, could I not delete the GAD29 (and save $1000) and use a seperate RS-232 connections from the GNX375 direct to the G5, and antother to each of the GDU116's? (there are plenty of RS-232 ports left).

IIRC, the arinc connection provides the vertical guidance and the rs-232 / mapmx provides the horizontal guidance and other info bits. So the G5 needs both paths for full gps guidance. The mapmx alone will provide a working solution, but just horiz guidance. That is for gps. The nav guidance only goes across the ARINC stream.

This is from memory, so maybe someone can confirm.

 

[AZ Cactus]

Do i just assume they are the same as the G3X? (aka they are all "Garmin Instrument Data").

I doubt the format of the output data of GSU 25 and GEA 24 changes when you change from a GDU 460/465 to an AXIS DU. I think it is safe to assume the format is Garmin Instrument Data.

 

[JeffPeters]

Can't answer your question, other than what little i've found the G5 still requires the GAD29 but don't ask me why.

I will say that I just ordered a completely identical system to what you've put together and will be here tomorrow. I'm currently building a spreadsheet that has every single device, connector, and pin out on it which i'll use to map all my connections, wire, color, awg, etc. Eventually a proper diagram from that too. Happy to share once I get it wrapped up.

What are you using for your diagram?

 

[MJarreau]

What are you using for your diagram?

Jeff,

We are (very sowly) working on our drawings in AutoCAD. FYI

Cheers!
Mike

 

[TASEsq]

Can't answer your question, other than what little i've found the G5 still requires the GAD29 but don't ask me why.

I will say that I just ordered a completely identical system to what you've put together and will be here tomorrow. I'm currently building a spreadsheet that has every single device, connector, and pin out on it which i'll use to map all my connections, wire, color, awg, etc. Eventually a proper diagram from that too. Happy to share once I get it wrapped up.

What are you using for your diagram?

I’m drawing it out in kicad and then using an excel to track each wire also. That does things like check the voltage drop over the wire length, and check wire size is appropriate etc. It also adds up the expected loads on the busses etc. it also tracks installation status.