HSI Bearing Pointers

[rvmills]

Bob,

I think you missed the original point of this thread.  In most cases, having an RMI pointing to the same VOR as the CDI is not necessary and just clutters up the screen.  What I am looking for is for the active VOR to drive the CDI (and glideslope) and for the standby VOR to drive one RMI only.  Dynon says this is supposed to work, but it doesn't.  I have been able to drive the 2nd RMI via the standby VOR only if the active VOR is driving the 1st RMI (as you described in your experience.)  Dynon, have I described the issue correctly?

Roger Johnson
LongEZ N34JR

Roger,

Concur, my post was more in reply to the later posts on a "locked" second bearing pointer (when both RMI needles point to the primary VOR). Apologies for adding to the thread creep.

Agree with you that deselecting the RMI bearing pointer to the primary VOR and using the CDI only for the primary course (when shooting a VOR approach or navigating to a VOR enroute) and then having just one bearing pointer for cross-radials would be a better (less cluttered) display. How does one de-select the first bearing pointer in that scenario? Is that an HS-34 thing, or is it do-able with no HS-34?

Of interest, when shooting that practice ILS yesterday, the SL-30's primary freq was set to the LOC freq, and the STBY freq was set to monitor a nearby VOR. The only RMI needle that showed was the STBY VOR (like the display you are saying you want). I wouldn't expect a LOC to show a bearing pointer anyway, but it was the Orange single needle that was displayed (which I believe normally points to the primary station) so during an ILS, the STBY freq was displaying the #1 RMI needle instead of the #2 (Yellow) RMI needle. Just an observation.

So hopefully this will give some focus back to your original query. Unless I'm reading it totally wrong, looks like a "two-fer"...maybe get two issues resolved with one thread...figure out how to drive just the STBY VOR RMI needle by itself (your case), and figure out how to unlock the second bearing pointer (for those that can't display the STBY VOR RMI needle separately).

Hope I didn't "clutter" your issue too much! (I know there is a declutter button on my keyboard somewhere...just can't find it!)

Cheers,
Bob

 

[aceflyingservice]

Bob,

Thanks for your input. I believe you have to have an HS34 to select/deselect nav inputs, both for the CDI and RMI. It's interesting that without an HS34, if the active Nav is tuned to a localizer freq, the standby Nav automatically uses the 1st RMI pointer. I think Dynon needs to do some general testing in this area. Hey, Dynon?

Roger Johnson
LongEZ N34JR

 

[dynonsupport]

One thing I noted was that winds were absent, which I would have expected, given that the selector switch was on SL-30 and not GPS. I know (or believe) that the HS-34 enables the display of GPS data, including winds, along with the VHF NAV data, but was wondering if there is anything short of an HS-34 (wiring or gizmo) that would allow the parallel/simultaneous streaming of VOR serial data and GPS NMEA data into pin 22 to get the same results (or is that just not possible...just thinking outside the box a bit here). If I do upgrade my SL-40 to an SL-30, just might have to go for the HS-34 as well!

In his configuration (one serial port via the D100, but two serial devices in the SL30 and GPS), there's no way to keep the GPS coming in at the same time as the radio to maintain the winds aloft. If you have either an HS34 or an EMS (as well as an EFIS), or a FlightDEK-D180, you'll end up with multiple serial ports that are monitored simultaneously, yielding winds that don't go away as you switch sources.

 

[dynonsupport]

Bob,

I think you missed the original point of this thread.  In most cases, having an RMI pointing to the same VOR as the CDI is not necessary and just clutters up the screen.  What I am looking for is for the active VOR to drive the CDI (and glideslope) and for the standby VOR to drive one RMI only.  Dynon says this is supposed to work, but it doesn't.  I have been able to drive the 2nd RMI via the standby VOR only if the active VOR is driving the 1st RMI (as you described in your experience.)  Dynon, have I described the issue correctly?

Yep. That's part of the HSI / SL30 weirdness that we'll trying to fix at the moment.

 

[dynonsupport]

How does one de-select the first bearing pointer in that scenario? Is that an HS-34 thing, or is it do-able with no HS-34?

This is an HS34 feature. Without the HS34, the bearings are always the ones available from the active HSI source.

 

[dynonsupport]

Bob,

Thanks for your input.  I believe you have to have an HS34 to select/deselect nav inputs, both for the CDI and RMI.  It's interesting that without an HS34, if the active Nav is tuned to a localizer freq, the standby Nav automatically uses the 1st RMI pointer.  I think Dynon needs to do some general testing in this area.  Hey, Dynon?

Roger Johnson
LongEZ N34JR  

If you're tuned to a loc, then you'll only have 1 bearing - to the standby freqency if it's valid. It should be labeled SBY to indicate it's the standby frequency, vs NAV if it's the primary.

A picture of what you're seeing in this case would help us out if that's possible.

 

[rvmills]

One thing I noted was that winds were absent, which I would have expected, given that the selector switch was on SL-30 and not GPS. I know (or believe) that the HS-34 enables the display of GPS data, including winds, along with the VHF NAV data, but was wondering if there is anything short of an HS-34 (wiring or gizmo) that would allow the parallel/simultaneous streaming of VOR serial data and GPS NMEA data into pin 22 to get the same results (or is that just not possible...just thinking outside the box a bit here). If I do upgrade my SL-40 to an SL-30, just might have to go for the HS-34 as well!

In his configuration (one serial port via the D100, but two serial devices in the SL30 and GPS), there's no way to keep the GPS coming in at the same time as the radio to maintain the winds aloft. If you have either an HS34 or an EMS (as well as an EFIS), or a FlightDEK-D180, you'll end up with multiple serial ports that are monitored simultaneously, yielding winds that don't go away as you switch sources.

DS,

My friend with the RV-9A actually has a EFIS D100 and an EMS D120, but no HS-34. He has the outputs of the SL-30 and GPS wired to a switch, then to pin 22 on the D100. A couple questions follow, just to make sure I am reading your reply correctly:

1. So if he connects the SL-30 into one Dynon, and the GPSMAP495 into the other, he can get a wind readout while getting VOR/LOC nav from his SL-30?

2. How is the wiring run for that, and how does the NAV source get switched between SL-30 and GPS?

3. With the SL-30 wired to one unit and the GPS wired to the other unit, can a GPS track also be displayed along with the VHF Nav radial?

I'll look at the install manuals and see if I can figure it out as well, but if you have any quick gouge on that part of the wiring piece, I'd really appreciate it!

Thanks much!

Cheers,
Bob

 

[rvmills]

Bob,

Thanks for your input.  I believe you have to have an HS34 to select/deselect nav inputs, both for the CDI and RMI.  It's interesting that without an HS34, if the active Nav is tuned to a localizer freq, the standby Nav automatically uses the 1st RMI pointer.  I think Dynon needs to do some general testing in this area.  Hey, Dynon?

Roger Johnson
LongEZ N34JR  

If you're tuned to a loc, then you'll only have 1 bearing - to the standby freqency if it's valid. It should be labeled SBY to indicate it's the standby frequency, vs NAV if it's the primary.

A picture of what you're seeing in this case would help us out if that's possible.

DS,

I'll try to get up with the gent with the D100/SL-30/GPSMAP495 again soon, and bring a camera. Will take a shot of the display with two VOR radials displayed (active and standby RMI needles), and another with a localizer on the CDI and one RMI needle from the STBY VOR. (I think that's what you're asking for!)

This will show what is displayed in this non-HS-34 install, and hopefully it will help in your troubleshooting efforts for HS-34 equipped installs!

Let me know if there is anything else you'd like to see.

Cheers,
Bob

 

[dynonsupport]

1. So if he connects the SL-30 into one Dynon, and the GPSMAP495 into the other, he can get a wind readout while getting VOR/LOC nav from his SL-30?

Yes.

2. How is the wiring run for that, and how does the NAV source get switched between SL-30 and GPS?

There are specific instructions for this in the install manuals, which he should reference. Under the HSI menu, there's a NAVSRC that toggles between the two serial sources.

3. With the SL-30 wired to one unit and the GPS wired to the other unit, can a GPS track also be displayed along with the VHF Nav radial?

GPS ground track, if available, is always displayed on the HSI as the magenta bug, even when the radio is being used on the HSI. However, without the HS34, the bearing pointers are always sourced from the active HSI source.

 

[rvmills]

Thanks guys...makes sense. Appreciate it!!

Cheers,
Bob