This information is provided for customization. You get a finished VDGS device with your license, ready to be copied into your airport project.

VDGS display units must be configured as standard SimObjects with custom VDGS parameters added to sim.cfg.

[fltsim.n] sections

Each VDGS unit must have a separate [fltsim.n] section in sim.cfg containing at least the required parameters listed below.

[vdgs_defaults] section

To avoid unnecessary repetition, both required and optional [fltsim.n] settings (except title) can have custom default values. They can be set with [vdgs_defaults] section. If a setting is not found under [fltsim.n], then the value in [vdgs_defaults] is used. If that is missing too, then internal defaults are used.

Required parameters


Unique title of the device. Must start with “noolaero VDGS”, followed by airport ICAO code and device ID. Device ID may be any string containing ASCII characters.

Example: title=noolaero VDGS NZAA G30


Unique group ID assigned to your airport and used to tell device groups apart. Value provided with your license.


Version of the module that this SimObject was built for.

Example: vdgs_version=2.1.0

vdgs_nose=<lat>, <lon>, <hdg>

Latitude, longitude and true heading of the location where nose wheel should end up.

Example: vdgs_nose=46.229853, 14.455198, 37.02

Optional parameters


Logic engine for the device to use:

Name Description
safedock Any type of Safedock device (default)
apis_1 APIS device with single-line display
apis_2 APIS device with double-line display
rlg_206 RLG GIS 206

Stand ID for devices that are capable of showing it. ASCII string and left-aligned by default. Use underscores for padding if needed.

Example: vdgs_stand=A12


Door offset from vdgs_nose in meters, where positive values are towards the device, negative away from it. When vdgs_door is set on device and aircraft has a front passenger door, guidance will align the door with vdgs_door position. If the aircraft does not have a suitable door, its nose wheel will be guided to vdgs_nose position.

vdgs_scan=<capturing>, <tracking>, <closing>, <stop_short>, <stop>, <too_far>, <overshoot>, <width>, <turn>

Scan area. Values from capturing to overshoot describe length of the scan area and width defines its width. If aircraft leaves the scan area, then the device gets reset. See Docking stages for visual depiction.

Longitudinal thresholds

Value Default Description
capturing 120.0 m Device becomes active and starts looking for aircraft
tracking 60.0 m Aircraft gets detected and device starts providing guidance
closing 20.0 m Device switches to final countdown, showing digital distance readout
stop_short 4.0 m Earliest acceptable stop position: if aircraft stops after this, then docking ends
stop 0.2 m Device shows STOP message
too_far -1.0 m Stopping after this threshold triggers TOO FAR message
overshoot -10.0 m Furthest edge of the scan area: if aircraft passes this, then the device turns off

Lateral thresholds

Value Default Description
width 20.0 m Width of the scan area
turn 0.2 m Maximum offset from centerline before left or right turn is commanded.

Default values

Default values depend on device type set with vdgs_system:

vdgs_system vdgs_scan default value
safedock 120.0, 60.0, 20.0, 4.0, 0.2, -1.0, -10.0, 20.0, 0.2
apis_1, apis_2 100.0, 60.0, 15.0, 1.0, 0.2, -1.0, -10.0, 20.0, 0.2
rlg_206 120.0, 50.0, 40.0, 1.0, 0.2, -1.0, -10.0, 20.0, 0.4
vdgs_speeds=[<dist> <speed>], [<dist> <speed>], …

A list of maximum allowed speed before SLOW DOWN message is triggered. Restrictions are defined in pairs where dist is distance from target and speed is maximum speed in meters per second.

Default: vdgs_speeds=30.0 4.0, 20.0 3.0, 10.0 2.0. This means that closer than 30 m, max allowed speed is 4 meters per second. With less than 20 m to go, it’s 3 m/s, and below 10 m it’s 2 m/s. These are also the default values.

vdgs_stops=[<offset> <type> <type> …], [<offset> <type> <type> …], …

A list of custom offsets applied to aircraft types, relative to vdgs_nose. offset is the offset in meters to apply and is followed by one or more ICAO aircraft type designators (type). Positive offset values are towards the device, negative values away from it.

Example: vdgs_stops=-2.0 AT72 AT73 AT75 AT76, 1.5 B752 B753

This shifts all types of ATR-72 away from the device by 2 meters and brings all B757 family aircraft 1.5 m closer.

Type groups are also supported. They are defined in noolaero-vdgs.cfg, their name must be 5 characters or longer, and you can use them like regular type codes. The example above can be simplified to: vdgs_stops=-2.0 ATR_72, 1.5 BOEING_757


Maximum heading offset at capture. Aircraft heading must be less than deg away from target heading (defined in vdgs_nose) to get captured.

Default: vdgs_capture_hdelta=10.0 (10 degrees).


Delay in seconds before an aircraft is considered stopped. When an aircraft stays still within stop_short and too_far thresholds for more than this delay, then VDGS device considers docking completed and shows appropriate message (STOP OK, OK, or TOO FAR depending on stop position).

Default: vdgs_stop_delay=5.0 (5 seconds).


How long in seconds to show docking assessment after docking completes. Device switches to arrival timer after the timeout.

Default: vdgs_complete_timeout=60.0 (60 seconds).


How long in seconds to show arrival screen after docking assessment. For example, on-block time is shown during this window. Device switches off after the given time.

Default: vdgs_arrival_timeout=60.0 (60 seconds).


How long in seconds to show departure screen. This is used for showing off-block time as the aircraft is being towed away. Docking device switches off after the timer runs out.

Default: vdgs_departure_timeout=60.0 (60 seconds).


Default poweroff delay in seconds before the device is powered off after docking completes and there’s nothing else to show.

Default: vdgs_poweroff_delay=180.0 (180 seconds).


Controls how quickly multi-part messages alterate, eg how long B737 and -500 each stay on screen when showing B737-500 type.

Default: vdgs_text_speed=4.0 (4 seconds).


Controls how long slowly alternating messages stay on screen, eg how fast current time and stand number alternate on APIS displays.

Default: vdgs_text_slow=8.0 (8 seconds).


Controls how long quickly flashing text stays on screen, used in multi-part error messages, eg STOP / TOO / FAST.

Default: vdgs_text_fast=0.5 (0.5 seconds).


This is a simple example that sets up two VDGS devices for Ljubljana airport (LJLJ) stands 3 and 4.

They use mostly default values, but some minor changes have been made:

  • aircraft is considered stopped after 3 seconds (instead of default 5),
  • devices power off 120 seconds after docking completes (instead of default 180),
  • stand 3 has 2.5 m/s speed limit in the last 10 meters (instead of default 2 m/s).



title=noolaero VDGS LJLJ 3
vdgs_nose=46.229853, 14.455198, 37.02
vdgs_speeds=30.0 4.0, 20.0 3.0, 10.0 2.5

title=noolaero VDGS LJLJ 4
vdgs_nose=46.230091, 14.454732, 37.02

Docking stages

This image depicts docking stages as defined with vdgs_scan relative to target point set with vdgs_nose.

Docking stages
Docking stages