Introduction

FIX is an acronym for Flight Information eXchange. It is a set of protocol specifications for exchanging information between aircraft avionics and flight systems. This specification and the protocols themselves are licensed under a Creative Commons license that allows anyone to modify and redistribute these documents without charge.

This is a community supported endeavor, with the primary goal of providing a standard method for avionics and flight control systems to communicate with one other in a vendor neutral way. These specifications and protocols are primarily geared toward the Experimental Amateur Built (E-AB) aircraft community. Keeping the specification open and free allows airplane builders to create their own devices and write their own software that will be able to communicate with other devices without need to pay for specifications or licenses. It also encourages collaboration in the development and improvement of the protocols themselves.

FIX is a protocol family. FIX Gateway is a program designed to pass data between disparate technologies that may or may not communicate with any of the FIX protocols. Examples of use are...

*Allow an Electronic Flight Information System (EFIS) communicate with a flight simulator. *EFIS communication to CAN-FIX or other FIX devices within the airplane *Conversion of data from one format to a standard FIX type. *Hardware interface to flight simulators. *Testing

#General Description

FIX Gateway is a plug-in based program written in Python. Which plug-ins are loaded is determined by the configuration file during the program start. Each of the plug-ins communicates with a central database of data items. Each data item represents a distinct aircraft data point. Airspeed, altitude or oil pressure are simple examples but control positions and radio frequencies are also examples.

The database is determined by a database configuration file that is read during start up. The user can modify this file if need be to customize the database for specific needs.

Possible Applications

The primary use case for FIX Gateway is to integrate all the disparate flight information in the aircraft for display on an Electronic Flight Information System (EFIS). PyEFIS is a Python based EFIS that is being developed in concert with FGW. This allows the EFIS designers to not have to worry about all the data interfaces that may be necessary and concentrate on development of the EFIS. FGW supplies a common interface through a network connection that abstracts the data so the EFIS does not care whether the data comes from a flight simulator, a real airplane or is just being managed manually by the programmer.

Once the EFIS program is finished and installed in the airplane it needn't be modified to get actual aircraft data. Only FGW configuration needs to be changed.

Another use for FGW is to make it easy to integrate flight simulator data into other system. The EFIS could be used as an instrument for the flight simulator. The entire aircraft panel could be duplicated in the EFIS/FGW and removed from the flight simulator itself. Interface to real equipment is simplified. Since FGW is written in Python it's quite easy to write a custom plug-in to read data from any source and write it into the database. Once in the database it's a simple matter of configuring other plug-ins to move that data to/from other sources.

For example, one plug-in could be written to read analog values from an Arduino and then that information could be used as pilot inputs to FlightGear, X-Plane or any other flight simulator that has an interface built for FGW. It could also be used as a real hardware interface for an actual aircraft as well but good engineering practices should be used here for obvious reason. Flight controls should probably be done by other means in an actual aircraft.

It's conceivable that different flight simulators could be tied together using this technology as well. You could be flying a 172 in FlightGear and your neighbor could fly with you in his RV using X-Plane. The plug-ins for the different flight simulators are not quite this sophisticated yet but it's possible.