Strange OBS operation with GPS in 1.3

[kneighbour]

This all worked just fine in V1.2 as far as I can recall. Funny things are happening in V1.3.

 

Set Nav selector to NAV S L. Set EHSI to ROSE mode

 

I setup a flight plan in the GPS and use the CDI button set it to GPS mode. The EHSI correctly goes to LRN1. The distance shown is correct.

 

The DTK on the GPS is 233 degrees. The MSG error comes up on the GPS, telling you to adjust the CRS to 233, The NAV Course pointer on the EHSI is showing 245 degrees and the digital bearing reading is 245 degrees as well.

 

This is all fine - usually what you do next is adjust the CRS1 control to move the NAV Course pointer to the GPS DTK - 233 in this case. When you adjust the CRS now (either with the CRS1 control on the pedestal, or with my hardware control), the CRS does change. When the Course is at 233, the MSG warning on the GPS goes out.

 

As you are doing this, the Course 1 Selection popup adjusts as you move the CRS1 knob on the pedestal. It does not move if I use my hardware switches connected to the OBS_HSI_down/OBS_HSI_up commands. But these commands do actually change the Course, it is just not indicated.

 

The problem is that the NAV Course pointer on the EHSI never moves. It remains at 245 degrees the whole time. It is not indicating the CRS.

 

If I change the active leg on the flight plan, the NAV Course pointer does move, but to what seems like a very random direction. No idea what the relation is to the direct track, but as far as I can see, there is no correlation.

 

If I put the GPS in GPS and OBS mode, the deviation indicator on the HSI works as normal - although it is perhaps a bit too sensitive. But it looks basically correct.

 

The Course 1 Selection popup displays correctly for the  CRS1 control, but not the X-Plane commands.

 

If I put the GPS in VLOC mode, the NAV Course pointer moves with the CRS1 control, and also the two X-Plane commands. The Course 1 Selection popup displays correctly for both X-Plane command control and CRS1 control. So this is all as expected.

 

If it is a problem (ie not as designed), then it seems to be the same on NAV S L or NAV S R.

[JGregory]

NOTHING has changed in V1.3 regarding the Course Selector(s), the GPS, or the Course pop-up display(s).

 

As for the rest of your post... I will need to check into this. A typical HSI only displays one course pointer. However, the EHSI on the Saab has the capability of displaying 2 course pointers, which complicates the simulation.  This will take some time to analyze.

 

In the meantime... you are using the wrong commands.  For now you need to use "sim/radios/obs1_up" and "sim/radios/obs1_down" for NAV1, and same except "obs2" for NAV2.  At this point, when in LRN1 mode, the course pointer will show the "relative bearing" to the waypoint, although you cannot adjust the course pointer when you are in LRN1 mode.  

 

If you want to know why there is a difference between the "relative bearing" and the DTK, you should switch between VLOC and GPS while observing the GPS display of the flight path.

 

BTW.. DTK is "Desired Track", not "Direct Track"... there is a distinction.

Edited June 29, 2015 by JGregory

[kneighbour]

BTW.. DTK is "Desired Track", not "Direct Track"... there is a distinction.

Sorry, slip of the tongue on my part.

 

The commands OBS_HSI_down/OBS_HSI_up do work just fine, but I will check out the commands you suggest. While they work, and DO adjust the CRS value (exactly the same as the CRS1 knob does), the HSI course needle does not change. My observation was that while these commands change the CRS value, they are not sensed by the Course popup display. I would not worry about the the popup display as usually the HSI needle changes.

 

If I enter a Direct To point in the GPS, then the HSI moves and points to the DTK. This saves you using the CRS1 adjustment to do the same thing, so a nice touch. So if there is any issue here, it is perhaps that the HSI is not picking up the DTK sometimes. Also, by automatically moving the HSI needle, and not the CRS setting, the MSG screen on the GPS is not cleared.

 

here is another example...

 

I loaded a new flight plan. The HSI correctly showed the first DTK. I then stepped through the flight plan segments, activating each and it correctly showed the first couple of legs, but the last one failed. It should be 105 degrees, but shows 62. The GPS MSG screen says to set CRS to 105. If I move the CRS1 knob, the popup shows the CRS settings at some random setting (259 in my case). The 62 does not seem to be related to anything. The three segments in this plan are 113, 032 and 105.

 

In the GPS I move to each segment and then Activate that segment using the Menu button. If I go to each segment and then press the Direct To, then the HSI will adjust correctly each time.

 

I use the HSI on other aircraft all the time. I usually fly using the GPS and the HSI, so I know how it works generally and with most other aircraft. In fact it was why I waited to buy this version of the 340A. I needed the GPS functionality. And on other a/c, HSI needle certainly moves with CRS adjustment in this mode. The 340A seems to be different, and if that is as designed, fine.

 

I have noticed this issue a bit as I have been using long flight plans, and often the HSI needle is not pointing to where I am flying. The aircraft still flies the flight plan ok and the autopilot tracks correctly. The deviation indicator on the HSI also seems to be working ok.

[kneighbour]

Funnily enough, the Copilot's system works as per normal.

 

And for other users, one way around the issue (on the Pilot's side). Align the Course needle on the HSI with the GPS in VLOC mode. This works as normal and the MSG indicator on the GPS will go out as you align the HSI. Then switch the GPS to GPS mode and all is well. The Course indicator will be correct and the GPS MSG indicator will be out.

Edited July 4, 2015 by kneighbour

[JGregory]

I have corrected the display of the course pointer to fix the above noted issues. This will be included in the next update.