X-PLANE REV 11.35 and 11.36r2
GTN 650 REV 2.5.19.1
Trainer GTN 6.62.0

Has anyone recently tried an LPV approach with the steam guage Laminar C172SP?

I just bought the RXP650 package. Installation ok with full functionality
for HSI equipped aircraft. All seems well except the C172SP.

The CDI needles behave correctly but no autopilot capture at GS intercept. Remains
at altitude.

The default Garmin works correctly (GTN disabled). Noted the GS always remains
flagged even during POWER ON SELF TEST which is not correct. The GTN works
correctly on ILS approaches. VNAV enabled on GTN.

Laminar recently updated the STEC55 model in version 11.30 but can't verify
earlier version functionality. Not sure if just set up issue???

 

Spoiler

[GTN]
; comma separated list of gauges
gauges = GTN_650_1

[GTN_650_1]
; comma separated list of render targets.
drawto = WINDOW, PANELS
; is the master device if true.
MasterDevice = true
; aviation db: 0: nav_db2_grm, 1: nav_db2, 2: nav_heli_db2_grmn, 3: nav_heli_db2
NavDbType = 1
LinkHsi = false
LinkVor = true
LinkObs = true
PowerSource = AVIONICS_BUS
AFMS.auto_nav_appr = 1
AutoGpsSource = 1
AutoNavSource = 1

[GTN_650_1.WINDOW]
; display window if true.
visible = true 
; show screen only gauge if true.
nobezel = false
; display type: WINDOW,PANEL2D,PANEL3D,PANELS
frame.type = WINDOW
; display position and dimension (left,top,width,height)
frame.rect = 1433,-21,480,202
; screen only border size (pixels).
border.size = 0
; screen only border color (#RGB or #RGBA).
border.rgba = #000000
; enable mouse clickspots if true, disable if false (use SHIFT to override)
usemouse = true 
; left mouse button on the screen toggles popup window if true (requires SHIFT+left mouse button).
popleft = false
; right mouse button on the screen toggles popup window if true (requires XP11.1).
popright = true 
; VR mode position and dimension (left,top,width,height) (requires XP11.20)
vrmode.rect = 0,350,830,350
; display as popout window if true (requires XP11.1).
undocked = false
; display mouse tooltips if true.
tooltips = false
; freeze display position if true.
locked = false
; auto hide in external view if true.
autohide = false

[GTN_650_1.PANELS]
; display window if true.
visible = false
; show screen only gauge if true.
nobezel = true
; display type: WINDOW,PANEL2D,PANEL3D,PANELS
frame.type = PANELS
; display position and dimension (left,top,width,height)
frame.rect = 0,0,0,0
; screen only border size (pixels).
border.size = 0
; screen only border color (#RGB or #RGBA).
border.rgba = #000000
; enable mouse clickspots if true, disable if false (use SHIFT to override)
usemouse = true
; left mouse button on the screen toggles popup window if true (requires SHIFT+left mouse button).
popleft = false
; right mouse button on the screen toggles popup window if true (requires XP11.1).
popright = true

[GTN_650_2]
; comma separated list of render targets.
drawto = WINDOW, PANELS
; is the master device if true.
MasterDevice = false
; aviation db: 0: nav_db2_grm, 1: nav_db2, 2: nav_heli_db2_grmn, 3: nav_heli_db2
NavDbType = 1

[GTN_650_2.WINDOW]
; display window if true.
visible = true
; show screen only gauge if true.
nobezel = false
; display type: WINDOW,PANEL2D,PANEL3D,PANELS
frame.type = WINDOW
; display position and dimension (left,top,width,height)
frame.rect = 993,981,830,350
; screen only border size (pixels).
border.size = 0
; screen only border color (#RGB or #RGBA).
border.rgba = #000000
; enable mouse clickspots if true, disable if false (use SHIFT to override)
usemouse = true
; left mouse button on the screen toggles popup window if true (requires SHIFT+left mouse button).
popleft = false
; right mouse button on the screen toggles popup window if true (requires XP11.1).
popright = true
; VR mode position and dimension (left,top,width,height) (requires XP11.20)
vrmode.rect = 0,350,830,350
; display as popout window if true (requires XP11.1).
undocked = false
; display mouse tooltips if true.
tooltips = false
; freeze display position if true.
locked = false
; auto hide in external view if true.
autohide = false

[GTN_650_2.PANELS]
; display window if true.
visible = false
; show screen only gauge if true.
nobezel = true
; display type: WINDOW,PANEL2D,PANEL3D,PANELS
frame.type = PANELS
; display position and dimension (left,top,width,height)
frame.rect = 0,0,0,0
; screen only border size (pixels).
border.size = 0
; screen only border color (#RGB or #RGBA).
border.rgba = #000000
; enable mouse clickspots if true, disable if false (use SHIFT to override)
usemouse = true
; left mouse button on the screen toggles popup window if true (requires SHIFT+left mouse button).
popleft = false
; right mouse button on the screen toggles popup window if true (requires XP11.1).
popright = true

[GTN_625_1]
; comma separated list of render targets.
drawto = WINDOW, PANELS
; is the master device if true.
MasterDevice = true
; aviation db: 0: nav_db2_grm, 1: nav_db2, 2: nav_heli_db2_grmn, 3: nav_heli_db2
NavDbType = 1

[GTN_625_1.WINDOW]
; display window if true.
visible = true
; show screen only gauge if true.
nobezel = false
; display type: WINDOW,PANEL2D,PANEL3D,PANELS
frame.type = WINDOW
; display position and dimension (left,top,width,height)
frame.rect = 762,-366,739,312
; screen only border size (pixels).
border.size = 0
; screen only border color (#RGB or #RGBA).
border.rgba = #000000
; enable mouse clickspots if true, disable if false (use SHIFT to override)
usemouse = true
; left mouse button on the screen toggles popup window if true (requires SHIFT+left mouse button).
popleft = false
; right mouse button on the screen toggles popup window if true (requires XP11.1).
popright = true
; VR mode position and dimension (left,top,width,height) (requires XP11.20)
vrmode.rect = 0,350,830,350
; display as popout window if true (requires XP11.1).
undocked = false
; display mouse tooltips if true.
tooltips = false
; freeze display position if true.
locked = false
; auto hide in external view if true.
autohide = false

[GTN_625_1.PANELS]
; display window if true.
visible = false
; show screen only gauge if true.
nobezel = true
; display type: WINDOW,PANEL2D,PANEL3D,PANELS
frame.type = PANELS
; display position and dimension (left,top,width,height)
frame.rect = 0,0,0,0
; screen only border size (pixels).
border.size = 0
; screen only border color (#RGB or #RGBA).
border.rgba = #000000
; enable mouse clickspots if true, disable if false (use SHIFT to override)
usemouse = true
; left mouse button on the screen toggles popup window if true (requires SHIFT+left mouse button).
popleft = false
; right mouse button on the screen toggles popup window if true (requires XP11.1).
popright = true

19/09/06 23:01:32.088 10764 -    ] # win.xpl version 2.5.19.1
19/09/06 23:01:32.088 10764 INFO ] 

19/09/06 23:01:35.807 10764 -    ] # rxpGtnSim64.dll version 2.5.19.1
19/09/06 23:01:35.807 10764 INFO ] 
19/09/06 23:02:04.102 10764 INFO ] GTN 650.1 - TRAINER 6620
19/09/06 23:03:10.793 01668 INFO ] GTN 650.1 - TRAINER 6620
19/09/06 23:55:29.013 01668 INFO ] GTN 650.1 - TRAINER 6620

 

Hi,

Just bought the GTN650 last week and got it to capture the glide-slope correctly with the X-Plane 11 C172SP using STEC55 on both LPV and LNAV/VNAV approaches.   My GS flag also remains flagged which looks like a bug.  However for me this bug does not cause any other problems.  I can imagine two possible causes for your problem:

1. When you do an LPV approach it is important that the ALT button be pressed a second time on the STEC55 so that its display says GS.  It will not track the glide slope unless GS is displayed.

2.  Even with GS displayed the STEC55 will still not track the glide slope if the plane is not BELOW the glide path when the leg that goes TO the Final Approach Fix is activated.  At the activation of this leg the GTN650 will first put up the LPV annunciation.  If you are two high and above the LPV glide path during activation of this leg then the STEC55 will not follow the glide slope.  This might be a holdover from the real-world ILS glideslope technology which does require entry below the glide path at the FAF in order to prevent capture of the more steep secondary glidepath.  Of course the real-world LPV approach technology does not have this problem but the STEC55 may still be programed to work with the ILS rules.

Good luck,

Larry

 

On 9/6/2019 at 8:11 PM, Throttle8899 said:

LinkHsi = false

Try 'Connect GPS to HSI' to see if this solves the X-Plane flag bug (limitation).

IIRC around 11.26 or 11.30 they've added new datarefs, 'mechanical' flags, which are not subject to their other 'override' datarefs. This makes gauges using these 'flag' datarefs to read the X-Plane value instead of ours.

Hi RXP,

Thanks for the suggestion.  Checking 'Connect GPS to HSI' made no difference to the GS flag failure.  I tried all the relevant settings:

Connect GPS to HSI

Connect HSI/CRS (auto-slew)

Connect HSI/OBS (input)

Connect GPS to VOR 1 indicator

Connect CDI Mode to NAV/GPS Switch

but the only one that had any effect on the CDI was:

Connect GPS to VOR1 indicator.

When this last one was deselected, the GS and LOC needles would not respond to the GTN 650 Instrument Panel Self Test and both flags had the red cross-hatch.  When this one was selected both needles properly deflected half left and half up, the LOC flag says 'TO' but the GS flag still has the red cross hatch.

There is one possible clew that may be either a Reality XP feature or an X-Plane indication of a conflict:  When I check the 'Connect GPS to VOR1 indicator' a greyed out message appears saying 'VOR# using Gauge Options > VLOC Source'.

Thanks for your help.

Larry

12 hours ago, larryweberplasma said:

a greyed out message appears saying 'VOR# using Gauge Options > VLOC

Yes this is normal, this tells you, like it is documented in the RXP GTN User's Manual, that in this case the set of datarefs which the GTN overrides is the one selected via the VLOC Source setting. This effectively allows you to use the GTN #1 and override the VOR #2 (instead of VOR #1)

Hi RXP

Thanks for the clarification.  I still have a lot to learn and I appreciate the clear explanation.

I got a new clew on the GS flag problem.  Somehow I got the system in a state where the RXP GTN650 would command the GS flag to be ON (blank flag, not red cross hatched).  The GS flag would be ON as long as the 650 was loaded.  If I unloaded the 650 by clicking the 'GTN650 1'  menu item under Plugins then the GS flag would go OFF (red cross hatched).  Then if I loaded the 650 back up, the flag would go ON again.  Once the flag was ON, while the 650 was loaded, it would stay ON independent of whether the GS needle was active or not.  In other words it was stuck ON as long as the 650 was loaded. 

I am not sure how to get the GS flag to become stuck ON.  After I did a few more flights during landing practice I noticed that the GS flag was stuck OFF again.

What is apparent is that the GS flag is being controlled by some variable within the RXP GTN650.  It does not appear to be some sort of interference with X-Plane variables.  I will keep an eye out for ways that might "control" whatever variable within the 650 is setting the GS flag state.

I am running X-Plane 11.36 with Reality XP 2.5.20 and SW Version 6.62.0 TRNG.

Larry

Thanks Larry for the followup on LPV GPS approaches. Out of town for some time and finally saw your answer. I just tried x-plane 11.40 and I still see the same response concerning the GS flag....so I think our installations are ok and will wait for future updates. Concerning GS capture, toggling ALT/GS mode at or near FAF has worked for me most of the time (GS still flagged)  but certainly not like ILS approaches which has always worked fine. The GTN650 configuration is popular with flight schools using legacy C172s so it is useful to study operational differences. I'm hoping they can somehow work in data base updates also!

Bob

11 minutes ago, Throttle8899 said:

I just tried x-plane 11.40 and I still see the same response concerning the GS flag....so I think our installations are ok and will wait for future updates.

Hi,

Can you please tell which aircraft your experiencing this with? If not a default, can you please try out with the default B58 and compare?

While at it, can you please report the following:

1. Validate these GTN 'Panel Instruments' settings are set:
   
   'Master Device', 'Connect CDI Mode to NAV/GPS Switch', 'Connect GPS to VOR1 indicator.' and/or 'Connect GPS to HSI'
    
2. Validate these GTN 'Gauge Settings' settings are set:
   
   'Pilot Side', 'GPS1'
    
3. When you're flying and reaching the point where GS flag should be out of view but it is visible instead, pause the sim.
    
4. Open datarefs editor
    
5. Report the values shown for the following datarefs:

"sim/cockpit2/radios/actuators/HSI_source_select_pilot"

"sim/cockpit2/radios/indicators/hsi_flag_from_to_pilot"
"sim/cockpit2/radios/indicators/hsi_flag_glideslope_pilot"
"sim/cockpit2/radios/indicators/hsi_flag_glideslope_pilot_mech"
"sim/cockpit2/radios/indicators/hsi_display_horizontal_pilot"
"sim/cockpit2/radios/indicators/hsi_display_vertical_pilot"

"sim/cockpit2/radios/indicators/nav1_flag_from_to_pilot"
"sim/cockpit2/radios/indicators/nav1_flag_glideslope"
"sim/cockpit2/radios/indicators/nav1_flag_glideslope_mech"
"sim/cockpit2/radios/indicators/nav1_display_horizontal"
"sim/cockpit2/radios/indicators/nav1_display_vertical"

 

Hello RXP,
Success using the GTN 650 capturing and following the GS with the default C172!
Referencing your note 1, I selected both "Connect GPS to VOR1 indicator" and "Connect GPS to HSI"
If both options were selected the approach was normal except for the GS flag which remained flagged.
I re-verified the initial failure several times by only selecting  "Connect GPS to VOR1 indicator".

(Using the latest GTN version 2.5.21.1 may also be necessary when using the default STEC55)
Thanks for the follow up,
Bob

  
values shown for the following datarefs with successful LPV approach and GS capture (but still flagged)

"sim/cockpit2/radios/indicators/hsi_flag_from_to_pilot" =1
"sim/cockpit2/radios/indicators/hsi_flag_glideslope_pilot" =0
"sim/cockpit2/radios/indicators/hsi_flag_glideslope_pilot_mech" =0
"sim/cockpit2/radios/indicators/hsi_display_horizontal_pilot" =1
"sim/cockpit2/radios/indicators/hsi_display_vertical_pilot" =1

"sim/cockpit2/radios/indicators/nav1_flag_from_to_pilot" = 1
"sim/cockpit2/radios/indicators/nav1_flag_glideslope" =1
"sim/cockpit2/radios/indicators/nav1_flag_glideslope_mech" =1
"sim/cockpit2/radios/indicators/nav1_display_horizontal" =0
"sim/cockpit2/radios/indicators/nav1_display_vertical" = 1
 

 

 

 

2 hours ago, Throttle8899 said:

(but still flagged)

The HSI datarefs seem to be correct (show both needles, hide both flags, show TO)

The NAV datarefs on the other hand do not agree and hide the horizontal needle and show the GS flag.

However both are connected to the GPS Source (provided the HSI source selector is set to GPS) and both should agree.

There might be a bug/limitation in X-Plane which prevents the NAV receiver to work like the HSI receiver when the source is the GPS despite our plugin explicitly requesting to override the GPS and the NAV datarefs sets.

I should have asked you these additional datarefs I've forgotten:

"sim/operation/override/override_gps"
"sim/operation/override/override_navneedles"
"sim/operation/override/override_nav1_needles"
"sim/operation/override/override_nav2_needles"

 

 

I did try to manually zero both the nav1  "flag_glideslope"  and  "flag_glideslope_mech" datarefs, but they are immediately overwritten
to a 1. Selecting both "Connect GPS to VOR1 indicator" and "Connect GPS to HSI" continues to work perfectly as far
as the approach is concerned, so this issue is not a constraint for me.

(I don't have the GTN 750 package so I am unable to verify if the same issue is present)

Status during a successful LPV approach:
"sim/operation/override/override_gps" =1
"sim/operation/override/override_navneedles" =1
"sim/operation/override/override_nav1_needles" =1
"sim/operation/override/override_nav2_needles" =0

Thanks for the insight

Thank you for the additional information.

This shows all datarefs are properly set in the 'override' mode, yet X-Plane is controlling the flags in a certain way which is not agreeing with the other datarefs.

X-Plane doesn't allow 'writing' the 'flag' datarefs and it is computing the flag state internally based on 'glideslope signal'. Unfortunately it should be removing the flag whenever 'override_nav#_needles' and 'override_gps' are set to 1 and the plugin writes the other 'relevant' datarefs like this one: "sim/cockpit/radios/gps_has_glideslope". It seems it is not doing so and we are yet to know why from XPlane devs.