ESI-500-style standby instrument

An electronic standby instrument for a 3 1/8" hole: attitude with synthetic vision, airspeed, altitude and heading tapes, VOR / ILS or GPS guidance, its pilot menu across the bottom and its battery. The knob sets the baro (pushed: STD); the Menu key opens the menu, as the real one's.

Modeled on: Sandia ESI-500-style electronic standby instrument
Category: Displays
Size: 1 cell
Version: 1.0 · 2026-10-19
Plan: Pro
Simulators: MSFS 2020 · MSFS 2024 · X-Plane 11 · X-Plane 12

Features

Attitude over the whole screen: the synthetic vision's terrain when there is a position (else blue sky and brown ground), the pitch ladder, the roll scale and pointer, the slip bar, the white chevron and wing bars
Airspeed tape at the left with its color bar and a drum readout: red past Vne or under Vs0 in the air, yellow past Vno; dashes under 20 kt
Altitude tape at the right with its drum readout and striped boxes for leading zeros, the metric readout, the vertical speed arrow, the baro at the top right (IN, HPA or MB; STD)
Heading tape along the bottom with its readout
NAV Mode: VOR / ILS (NAV 1, against the ESI's own selected course, as the real one) or GPS (the desired track): source and TO / FR, the course, the lateral and vertical scales, B/C, the marker beacons, the course arrow on the heading tape
Pilot menu (table 2-1): turn to scroll, push to choose, one line of sub-menu; Menu or 10 s closes it; Menu held: brighter
Power-up: the splash, then ATT ALIGNING with its green bar; on its battery without the aircraft power (its icon green, amber, red), BATT Shutdown in the menu
No simulator counterpart: the selected course, the data field, the brightness, the alignment, the battery
Square charcoal unit with rounded corners, the Menu key, the card slot, the light sensor and the big knob between two white arcs; the plate plain where the maker prints its logo

Your aircraft: The airspeed tape's color bar and its red and yellow readouts use the profile's V-speeds (Vs0, Vno, Vne).

On the iPad

Drag the knob up or down to set the baro; tap it for STD
Tap Menu for the pilot menu; drag the knob to scroll, tap it to choose; Menu again or 10 s to close
Hold Menu with the menu closed for brightness

Keys and controllers

Map any of these to a key, a game controller's button or axis, or a MIDI knob (how):

Baro +
Baro -
Baro sync

Simulator data

What the Hub reads from the simulator for this instrument, and what the instrument sends back. Names are the simulators' own: MSFS SimVars and events, X-Plane datarefs and commands.

Reads

Value	MSFS	X-Plane
Pitch attitude, + nose up (deg)	`ATTITUDE INDICATOR PITCH DEGREES (degrees)`	`sim/flightmodel/position/theta`
Bank angle, + right wing down (deg)	`ATTITUDE INDICATOR BANK DEGREES (degrees)`	`sim/flightmodel/position/phi`
Slip/skid ball position, -1..1	`TURN COORDINATOR BALL (position)`	`sim/cockpit2/gauges/indicators/slip_deg`
Indicated airspeed (kt)	`AIRSPEED INDICATED (knots)`	`sim/cockpit2/gauges/indicators/airspeed_kts_pilot`
True airspeed (kt)	`AIRSPEED TRUE (knots)`	`sim/flightmodel/position/true_airspeed`
Indicated altitude (ft)	`INDICATED ALTITUDE (feet)`	`sim/cockpit2/gauges/indicators/altitude_ft_pilot`
Vertical speed (fpm)	`VERTICAL SPEED (feet per minute)`	`sim/cockpit2/gauges/indicators/vvi_fpm_pilot`
Altimeter setting (inHg)	`KOHLSMAN SETTING HG (inHg)`	`sim/cockpit2/gauges/actuators/barometer_setting_in_hg_pilot`
Heading (glass AHRS heading, else magnetic heading) (deg magnetic)	`HEADING INDICATOR (degrees)`	`sim/cockpit2/gauges/indicators/heading_AHARS_deg_mag_pilotsim/flightmodel/position/mag_psi`
Outside air temperature (degC)	`AMBIENT TEMPERATURE (celsius)`	`sim/cockpit2/temperature/outside_air_temp_degc`
On the ground (1/0) (bool)	`SIM ON GROUND (bool)`	`sim/flightmodel/failures/onground_any`
NAV1 receiving a station (1/0) (bool)	`NAV HAS NAV:1 (bool)`	`sim/cockpit2/radios/indicators/nav1_flag_from_to_pilot`
NAV1 receiver course deviation, + = course right (dots (-2.5..2.5))	`NAV CDI:1 (number)`	`sim/cockpit2/radios/indicators/nav1_hdef_dots_pilot`
NAV1 TO/FROM: 0 off, 1 TO, 2 FROM (enum)	`NAV TOFROM:1 (enum)`	`sim/cockpit2/radios/indicators/nav1_flag_from_to_pilot`
NAV1 OBS course (deg)	`NAV OBS:1 (degrees)`	`sim/cockpit2/radios/actuators/nav1_obs_deg_mag_pilot`
The NAV source is a localizer (1/0) (bool)	`NAV HAS LOCALIZER:1 (bool)GPS DRIVES NAV1 (bool)`	`sim/cockpit2/radios/actuators/nav1_frequency_hzsim/cockpit2/radios/actuators/HSI_source_select_pilot`
Glideslope valid (1/0) (bool)	`HSI GSI NEEDLE VALID (bool)`	`sim/cockpit2/radios/indicators/hsi_flag_glideslope_pilot`
Glideslope deviation (dots)	`HSI GSI NEEDLE (number)`	`sim/cockpit2/radios/indicators/hsi_vdef_dots_pilot`
GPS desired track (deg)	`GPS WP DESIRED TRACK (degrees)GPS IS ACTIVE FLIGHT PLAN (bool)`	Not available
GPS's own course deviation (dots)	`GPS CDI NEEDLE (number)`	`sim/cockpit2/radios/indicators/gps_hdef_dots_pilot`
GPS flight plan active (1/0) (bool)	`GPS IS ACTIVE FLIGHT PLAN (bool)`	Not available
Distance to the active waypoint (nm)	`GPS WP DISTANCE (nautical miles)GPS IS ACTIVE FLIGHT PLAN (bool)`	Not available
Marker beacon: 0 none, 1 outer, 2 middle, 3 inner (enum)	`MARKER BEACON STATE (number)`	`sim/cockpit2/radios/indicators/outer_marker_litsim/cockpit2/radios/indicators/middle_marker_litsim/cockpit2/radios/indicators/inner_marker_lit`

Sends

When you…	MSFS	X-Plane
Turning the knob, or mapped 'Baro +' / 'Baro -'	`KOHLSMAN_SET`	`sim/cockpit2/gauges/actuators/barometer_setting_in_hg_pilot`
Pushing the knob (STD), or mapped 'Baro sync'	`KOHLSMAN_SET`	`sim/cockpit2/gauges/actuators/barometer_setting_in_hg_pilot`

Add-on aircraft with their own systems may use other variables; the Hub reads the standard ones.