Garmin GNC 215

[Tan]

I just picked up my plane with a new install of a GNC 215 nav/comm radio. My setup is dual G5s, 650xi and GFC 500.00. The GNC has a cdi loc indicator which allows me to select OBS. When I select VOR/VLOC2 on the G5 HSI I can select a course they both do not sync. Can anyone confirm they are suppose to sync as if I change the course with either knob they should both move. Currently each unit can select an independent course.

 

[Jon Wilder]

I just picked up my plane with a new install of a GNC 215 nav/comm radio. My setup is dual G5s, 650xi and GFC 500.00. The GNC has a cdi loc indicator which allows me to select OBS. When I select VOR/VLOC2 on the G5 HSI I can select a course they both do not sync. Can anyone confirm they are suppose to sync as if I change the course with either knob they should both move. Currently each unit can select an independent course.

They don't sync. The G5 does not send anything back to the GNC 215, nor does it accept resolver information from an external LRU.

There is also a note on page 4-9 of the GNC 215 Pilots Guide that reads -

"Information provided by the on screen CDI is for backup purposes only. Do not use for primary navigation."

 

[AvNavCom]

They don't sync. The G5 does not send anything back to the GNC 215, nor does it accept resolver information from an external LRU.

Presumably a G5 limitation, as the GI 275 is capable of sending OBS information to the GNC 215 to drive that supplemental display, in which case the latter doesn't offer OBS input, instead getting it from the GI 275 only.

An OBS selected course field accompanies the CDI scale. Manual course adjustments are not available while receiving selected course input from the external CDI/HSI.

 

[Jon Wilder]

Presumably a G5 limitation, as the GI 275 is capable of sending OBS information to the GNC 215 to drive that supplemental display, in which case the latter doesn't offer OBS input, instead getting it from the GI 275 only.

This is because the GI 275 interfaces over Ethernet (High Speed Data Bus), which is a full duplex interface. G5 only accepts ARINC 429 data from the GNC 215, but does not use the resolver information sent from the GNC 215. 429 communication is not two way between the two over 429 (only one 429 path exists going from the GNC to the G5).

 

[asicer]

This is because the GI 275 interfaces over Ethernet (High Speed Data Bus), which is a full duplex interface. G5 only accepts ARINC 429 data from the GNC 215, but does not use the resolver information sent from the GNC 215. 429 communication is not two way between the two over 429 (only one 429 path exists going from the GNC to the G5).

I believe the G5 can also talk RS232 to the GNC215, which is full-duplex.

 

[Jon Wilder]

I believe the G5 can also talk RS232 to the GNC215, which is full-duplex.

A GNC 215 installed as the #2 NAV only implements the 429 path as the 232 interface connects to navigator #1 only. In this installation with a GTN, the 232 interface on both G5's is used for GPS ADAHRS aiding (MapMX). It will only receive RS-232 data, but not transmit back as the TX/RX from the G5 is not implemented.

 

[asicer]

A GNC 215 installed as the #2 NAV only implements the 429 path as the 232 interface connects to navigator #1 only. In this installation with a GTN, the 232 interface on both G5's is used for GPS ADAHRS aiding (MapMX). It will only receive RS-232 data, but not transmit back as the TX/RX from the G5 is not implemented.

Ah, ran out of interfaces. I suppose that’s one advantage of the GI275

 

[Tan]

A GNC 215 installed as the #2 NAV only implements the 429 path as the 232 interface connects to navigator #1 only. In this installation with a GTN, the 232 interface on both G5's is used for GPS ADAHRS aiding (MapMX). It will only receive RS-232 data, but not transmit back as the TX/RX from the G5 is not implemented.

Hi Jon, So garmin is saying the G5 HSI should sync with the gnc 215 but I've heard mixes reports that it doesn't send information back to the GNC 215. I also do not get GPS info to the 215. Shop states they connected the unit via HSDB 650xi to gnc 215.

 

[Jon Wilder]

Hi Jon, So garmin is saying the G5 HSI should sync with the gnc 215 but I've heard mixes reports that it doesn't send information back to the GNC 215. I also do not get GPS info to the 215. Shop states they connected the unit via HSDB 650xi to gnc 215.

What are the exact symptoms you're experiencing? Tell us what indications you are getting/not getting that led to the conclusion of the GNC 215 not receiving GPS. It's quite possible the HSDB settings are not properly configured, or that they mis-pinned the HSDB connections if this is indeed the case. But we need to know what the exact symptoms are that you're experiencing.

It's very possible that the GTN passes the G5's resolver info to the GNC over HSDB (the GTN has the EFIS/Air Data 429 interface coming into it from the G5). But if the HSDB interface is not working correctly, that would explain why they're not syncing.

 

[Tan]

What are the exact symptoms you're experiencing? Tell us what indications you are getting/not getting that led to the conclusion of the GNC 215 not receiving GPS. It's quite possible the HSDB settings are not properly configured, or that they mis-pinned the HSDB connections if this is indeed the case. But we need to know what the exact symptoms are that you're experiencing.

It's very possible that the GTN passes the G5's resolver info to the GNC over HSDB (the GTN has the EFIS/Air Data 429 interface coming into it from the G5). But if the HSDB interface is not working correctly, that would explain why they're not syncing.

I get a No GPS for waypoint info and non of my frequencies show IDs nor do I get distance to VOR just a blank nm indicator. I also do have a good signal on my GTN650XI as it shows IDs once it acquires the signal which should transfer gps info to the 215. I have updated databases on both units that match and are same cycle. NAV and radio work fine. I can select VOR2/LOC2 on my G5 HSI so the G5 is receiving the signal from the GNC 215. I change radial/course on both units separately so they are not synced.

 

[Jon Wilder]

Yeah it sounds like the installing shop needs to diagnose the HSDB communication between the GNC and the GTN.

On the GTN, when you go to Home—>System—>External LRUs, what LRUs does it show?