X Plane

X-Plane

The xplane plugin feeds the database from X-Plane 11 or 12 over UDP, so a panel can be flown on the bench before it is in an airplane. It reads X-Plane's Data Output rows and named datarefs, and can write datarefs back.

Plugin reference: doc/plugins/xplane.rst. It is off in the shipped config: set XPLANE: true and turn DEMO off, since both write attitude (see Configuration).

X-Plane settings

• Data Output: send the rows below by UDP to the gateway machine's address, port udp_in (49001).
• Network: the gateway sends to udp_out (49000), X-Plane's legacy receive port. The newer port (49010) does not accept dataref requests.
• The host firewall on the X-Plane machine must allow inbound UDP on 49000, or the dataref requests are dropped silently while Data Output still arrives.

Settings

Option	Default	Meaning
ipaddress	127.0.0.1	X-Plane's address, where requests and writes are sent
udp_in	49001	local port the gateway listens on
udp_out	49000	X-Plane's port
recv	{}	Data Output rows to keys
datarefs	{}	named datarefs to keys
dataref_hz	10	dataref update rate requested
rref_resubscribe	5.0 s	how often the dataref requests are resent, so they survive an X-Plane restart
dataref_writes	{}	keys written back to datarefs
send, send_interval	{}, 0.1 s	keys sent as Data rows (commented out in the shipped file)

Data Output rows (recv)

Each row index maps its eight values to keys; _ skips a value. The shipped file, laid out for X-Plane 12:

recv:
  3:  [IAS, _, TAS, GS, _, _, _, _]
  17: [PITCH, ROLL, _, _, HEAD, MAGVAR, _, _]
  20: [LAT, LONG, ALT, AGL, _, _, _, _]

It also maps rows 4 (VS, ALAT), 16 (ROT) and 18 (AOA, TRACK, VPATH). Values of -999 (X-Plane's "no data") are dropped.

Named datarefs (datarefs)

KEY: dataref, or KEY: [dataref, scale]:

datarefs:
  EXTCRS:  sim/cockpit/radios/gps_course_degtm
  EXTCDI:  [sim/cockpit/radios/gps_hdef_dot, 0.4]

The shipped file subscribes the X-Plane GPS as the external navigator (EXTCRS, EXTCDI, EXTTF, and its glidepath EXTGSI/EXTGSF; select it with GPSSRC = 1, see Flight Plan Engine), both NAV radios' course, deviation, glideslope and TO/FROM, the VOR bearings, and HEADBUG.

Writing back (dataref_writes)

dataref_writes:
  XPHSISRC: sim/cockpit2/radios/actuators/HSI_source_select_pilot

A write is sent only when the key changes. In the shipped entry XPHSISRC is NAVSRC (through compute), so X-Plane's pilot HSI source follows the source selected on the panel, and the sim's own autopilot tracks it.

Staleness

The plugin has no timeout of its own. When X-Plane stops sending, keys go old through their tol (PITCH 300 ms, IAS 2 s, EXTCRS 5 s), and the panel flags them.