Advanced Solutions for Flight Simulation


A Guide To the GNS.INI

The GNS.INI file is a repository of various aircraft configurations, keyboard and event controls, and options for the Mindstar Aviation GNS 430/530 software.  Understanding this file is important if you intend to put the GNS into aircraft other than the default Cessna 172.

The GNS.INI is a plain text file.  It can be edited with Notepad.  It can be found in the folder you selected during the installation of the software.  Typically this would be

C: \ Program Files (x86) \ Mindstar \ Flight Simulator Addons \ GNS.INI.

Sections of the GNS.INI

The GNS.INI is broken down into several sections.  Each section is enclosed in square brackets.  Some of the sections you will see are:

[GNS] This section contains settings and options for the GNS 430/530 software.
[AIRCRAFT.DEFAULT] This section contains additional settings for individual aircraft using the 430/530 software.
[KEYBOARD] This section is where you can define keyboard shortcuts, SimConnect events, or FSUIPC offsets that the GNS software should pay attention to for hardware knobs and buttons that are being used to control the 430 or 530.  The name is KEYBOARD because in our earliest versions of the software, only keyboard shortcuts were supported.  But over the years, we have incorporated SimConnect and FSUIPC support into the software, but the section name has remained KEYBOARD.

Settings in the GNS.INI

Except for a few of the options below, most settings in the GNS.INI file are yes/no settings, or a numeric value.   This is different for a few items, as described below in the detail for the various sections.  

For yes/no settings, you can use the words YES, or NO, or the words TRUE or FALSE, or the numbers 1 or 0.   The effect is the same no matter which method you use to answer in the affirmative or negative. 

You should never put anything on the line other than the keyword, and the value.  Do not put the double-slash comment marker on any data line unless you are trying to comment out the entire line.   If you want to put comments in the file, put them on their own line, with the line starting with the double-slash.  For example:

// This is a comment line on a line by itself, and this is ok.

You can also comment out settings altogether with this double-slash, to make that line have no effect on the GNS software.:


But you cannot put comments after the value, like this:

YOUR_SETTING=TRUE // you cannot put comments here

Default Values

Some values of settings in the GNS.INI will be set to a default value if the item is not specified.   The charts below will show the default value in bold in the column for "Possible Values"

GNS.INI Sections - Detailed List

[GNS] Section - List Of Settings

Setting Possible Values Description
iSimConnect AUTO
For certain functions like traffic population and other built in functions that rely on the presence of SimConnect, this value defines which version of SimConnect to expect on the computer. If no match is found, the highest available version of iSimConnct is used.

It is strongly recommended that you use AUTO unless you have a specific reason to change it.

Leaving the setting out of the INI file altogether results in AUTO being automatically selected for you.
CheckForUpdates YES
This setting is for future use.  There is a facility inside the GNS that can  check whether a new version of the software is available.  But this facility is temporarily out of service used until it can be further enhanced.  At this time, this option should be set to NO.
GpsRedrawRate 1 - 10
Default is 4
The real GNS does not update the moving GPS map as quickly as flight simulator does.  This setting defines the number of seconds in between moving map updates.   For performance reasons, this setting should not be changed unless a problem is occurring.
NrstRange 100 Specifies the number of nautical miles to be used as a radius when create a list of items in the GNS "nearest" pages, such as nearest airports, nearest VOR's, nearest NDB's, etc.
Specifies the orientation of the various GPS maps in the various G1000 screens.
Specifies whether the moving map automatically zooms closer into a waypoint as the aircraft is about to pass the waypoint.
Specifies whether a cyan arrow emits from the small airplane on the moving map, indicating where the aircraft will be in 10 seconds based on current ground speed.
Specifies whether the MFD should display a small box in the upper right corner indicating the direction and strength (ini knots) of the wind.  The heading and direction are computed from GPS information.
For future use.
Specifies whether a small color legend is displayed on the MFD moving map showing the colors of various elevations of terrain.
Specifies whether colored topography is displayed on the moving map.  The colors are standard, and are based on the ground elevation of the area being depicted.
For Future Use.
For Future Use.
Specifies whether two concentric green circles are drawn on the MFD moving map to denote the range of the aircraft when the fuel level reaches the authorized reserve quantity, and when it runs completely out of fuel. The calculation is based on current fuel consuption levels.
After the 9/11 attacks, a number of special airspaces were defined around the Washington DC area.  At the present time, this special airspace is designated a "Special Flight Rules Area" or SFRA, with an additional special operations area called the Leesburg Maneuvering Area (LMA) positioned inside the SFRA.  This setting specifies whether the Washington DC SFRA and LMA are depicted on the GPS moving map with yellow lines and arcs.
If the GNS 430 or 530 appears in the panel.cfg in a popup window as well as in the 2D cockpit and/or the 3D Cockpit, the softwarewill stop displaying anything on the panel mounted instances of the GNS unit(s) when the popup version (zoomed version) is visible.  This is done to preserve frame rates, otherwise many computers would struggle with sluggish performance during the time that both the panel mounted unit and the one and the popup are both visible simultaneously.  To inihbit this performance-saving feature, you can set this option to YES, but it is strongly discouraged due to the potential adverse impact on simulator performance. (This feature was introduced in the Spring of 2017).
This setting controls which navigation database is used by the avionics.   If you are using Prepar3D, the MICROSOFT setting will still use the data internal to the sim.
(Optional) This optional parameter tells the GNS units which electrical bus powers them.  Typically, in a fixed wing aircraft, the GNS is powered by the avionics bus, which means that both the master switch and avionics switch must be switched on for the GNS to get power (thus AVIONICS is the default setting).

However in some aircraft, the GNS is powered by the main bus, either by the battery or the alternator.      In this case, use MASTER to make the GNS power up with only the master switch.

Use of the CUSTOM option is only useful for customers who have purchased a custom electrical system simulation from Mindstar.

Options For AIRCRAFT.DEFAULT Sections in GNS.INI

Setting Possible Values Description
AnimateStartup YES
Specifies whether the G1000 should display the power-up sequence when the master switch is turned.  The power-up sequence includes AHRS alignments and other tests that appear on the PFD in the first seconds after the master switch is turened on.

[KEYBOARD] Section Overview

The [KEYBOARD] section is a list of GNS 430 & 530 functions that can be controlled by hardware events generated by knobs and buttons, or keyboards.   Three control methods are supported - 1) keyboard shortcuts, 2) SimConnect events, and 3) FSUIPC offsets.  Each of the control methods are described in more detail below.

The section name [KEYBOARD] is a throwback to many years ago, prior to FSX, when the only control method available in our software was keyboard shortcuts.  Over time, we added support for SimConnect and FSUIPC, but the section name remains the same.  Don't let the name fool you!

The syntax used on each of the event lines is how the GNS detects which control  method is used.   Multiple control methods can be mixed within the file, but only one control  method can be coded on any particular function.

You may use Windows Notepad or any other text editor to make changes to this file.

Method 1: Triggering GNS Events using Keyboard Shortcuts

Using keyboard shortcuts to control the GNS is the most simplistic of the control methods, and it should not be used unless both of the other options below are not practical for you.  

When defining keystrokes into the INI file, use only the lower-case version of a key, with modifier keywords.  Valid modifiers for keyboard shortcuts are the words SHIFT, CTRL, and ALT.  The modifier must be separated from the key definition by a "+" sign.   To further understand modifiers, consider this - you must not use the "@" as a keyboard shortcut, but instead, you must type SHIFT+2 on the INI file line.  Letters can be coded as upper or lower case, but there is no distinction. for example, between an upper-case G and a lower-case g.   They are both recgonized as the same key.   If you want to code a G and a SHIFT+G, then those two are distinguished as separate keys.

Any keyboard shortcuts assigned to GNS functions will not be acted upon by flight simulator, even if you code a function that flight simulator would otherwise recognize.  For example, if you assing the letter "G" to a GNS function, the simulator will no operate the aircraft landing gear as it usually would with the "G" key because the GNS retains the keystroke and does not forward it to flight simulator.

One drawback of using keyboard shortcuts for GNS functions is that the main simualtor window (the one with the menubar) must be the window "in focus" in order for keys to reach the simulator.   If you have a popup window open, GNS shortcut keys will not reach the software, even if the popup window is a GNS element.

     Formatting Example for Keyboard Shortcuts:

Method 2: Triggering GNS Events with SimConnect

SimConnect was introduced by Microsoft in FSX, and continues to be in use by Lockheed-Martin in Prepar3D.  It is the preferred method of controlling the GNS from hardware.  SimConnect events are generated by your hardware driver software that is programmed to connect to Flight Sim using the SimConnect interface.    This means either you, or your hardware vendor, must have written a program that interfaces your hardware to flight simulator. 

SimConnect events for the GNS use any hex number between and inclusive of 0x11000 to 0x11FFF.  The number must be coded in the INI file with the 0x prefix in order to be recognized as a SimConnect event.  The GNS will monitor the SimConnect event stream for the specified event, and if that event appears, the GNS will execute the action to which the event number was assigned.

     Formatting Example for SimConnect Events:

     Example C++ Code for Sending Events via SimConnect

Method 3: Triggering GNS Events with FSUIPC Offsets

FSUIPC must be installed and operating on your computer in order to use this control method.  The GNS installer does not install FSUIPC because no internal functions of Mindstar Aviation software rely on FSUIPC. If you want to use the FSUIPC control method, then it is your responsibility to install the latest version of FSUIPC.

To use this method, Enter values on the event lines in the format FSUIPC:0x1234567 where 1234567 is any avaialble FSUIPC offset based on the FSUIPC documentation.  The GNS expects the offset to be an integer in the range of 0 to 255.  Each time the value at the specified FSUIPC offset increments, the GNS will execute the specified function.   If the value at the offset increments more than once, then the GNS will interpret that as a request to repeat the specified function for the number of times the value changed.   Once the value reaches 255, your hardware driver software should return the value to 0 and start incrementing again from there.

     Formatting Example for FSUIPC:

[KEYBOARD] Section - List Of Events

Function Description
GPS #1 Controls
GPS1_COM_VOL_PRESS Presses the COM VOL knob
GPS1_NAV_VOL_PRESS Presses the NAV VOL knob.
GPS1_COM_FREQ_TOGGLE Toggles the active and standby COM frequencies in GPS #1
GPS1_NAV_FREQ_TOGGLE Toggles the active and standby NAV frequencies in GPS #1
GPS1_LARGE_CV_INCR CW turn of the large COM/NAV knob that increases  megahertz in the selected COM or NAV radio in GPS #1
GPS1_LARGE_CV_DECR CCW turn of the large COM/NAV knob that decreases  megahertz in the selected COM or NAV radio in GPS #1
GPS1_SMALL_CV_INCR CW turn of the small COM/NAV knob that increases  kilohertz in the selected COM or NAV radio in GPS #1
GPS1_SMALL_CV_DECR CCW turn of the small COM/NAV knob that decreases  kilohertz in the selected COM or NAV radio in GPS #1
GPS1_SMALL_CV_PRESS Press the small COM/NAV knob on GPS #1
GPS1_CDI Toggles the CDI selection on GPS #11 between GPS and VLOC
GPS1_OBS Activates OBS mode.  When activated, the OBS knob on the VOR 1 gauge controls the selected course to the current GPS waypoint.
GPS1_MSG Press the MSG button on GPS #1 to view any pending messages.
GPS1_FPL Displays the flight plan screen on GPS #1
GPS1_VNAV For 530 only.  Activates the VNAV functions.
GPS1_PROC Presses the PROC button that displays a selection list of procedures for Departures, Arrivals, and Approaches..
GPS1_RANGE_INCR Increase the range on the GPS map on GPS #1
GPS1_RANGE_DECR Decrease the range on the GPS map on GPS #1
GPS1_DIRECT_TO Press the Direct-To button on GPS #1
GPS1_MENU Press the MENU button on GPS #1
GPS1_CLR Press the CLR button on GPS #
GPS1_CLR_HOLD Simulates the holding down of the CLR button (usually after 3 seconds) which causes the display to return to the default view on GPS #1
GPS1_ENT Press the ENT button on GPS #1
GPS1_LARGE_GPS_INCR CW turn of the large GPS (FMS) knob on GPS #1
GPS1_LARGE_GPS_DECR CCW turn of the large GPS (FMS) knob on GPS #1
GPS1_SMALL_GPS_INCR CW turn of the small GPS (FMS) knob on GPS #1
GPS1_SMALL_GPS_DECR CCW turn of the small GPS (FMS) knob on GPS #1
GPS1_SMALL_GPS_PRESS Press the small GPS (FMS) knob on GPS #1
GPS #1 Failures
GPS1_RAIM_PREDICTION_FAILURE_TOGGLE Toggles raim PREDICTION failure on and off.   When toggled on, and the RAIM prediction functions of the AUX pages are used to determine if RAIM will be available at the destination airport at the time of arrival, the prediction will report that RAIM will *NOT* be available.
GPS1_RAIM_ACTUAL_FAILURE_TOGGLE Toggles ACTUAL raim failure on and off.  When failed, the GPS is not reliable for navigation because of insufficient sattellite coverage.
GPS1_FAIL_GS_TOGGLE Toggles the failure of the glideslope display.
GPS1_FAIL_GS_SET Sets the failure state of the glideslope display.
GPS #2 Failures
Same names as the GPS1 counterparts, but prefixed with GPS2
Same as the GPS #1 counterparts


The USER_WAYPOINTS section is where the GNS software stores user-defined waypoints entered from either of the units.  The format consists of a waypoint name, followed by a series of parameters. 

You typically do not need to edit this section manually.  Incorrect values in this section could cause flight simulator to crash, so if you do decide to edit this section manually, use caution, and make backup copies of the GNS.INI file.

To understand the layout of each line, here's an example.  If we wanted a user defined waypoint named ABCDEF, it might appear like this:

MINDST=N39* 3.44', W77* 32.672', FDK211 / 23, FDK, 211.4, 22.7, N39* 24.73', W77* 22.508', , 0.0, 0.0, N0* 0.00', E0* 0.000'
ABCDEF=N39* 1.26', W77* 33.270', AML333 / 7, AML, 332.8, 6.6, N38* 56.07', W77* 28.001', , 0.0, 0.0, N0* 0.00', E0* 0.000'

Tip:  Do not change the last six paramters and use these lines as an example of how to create users waypoint in the GNS system.