Files upload and download API
The ACARS system is capable of simple file transfer. Given the purpose of the system, the transfer is never directly station to station, but always in terms of a store-and-forward buffer.
All files of a (virtual) company are isolated in their own namespace, based on the three-letter company code. A ground station, such as a dispatch client, "publishes" a file with a name that typically relates it to a specific flight, or a specific route. Airplane clients then request data from their dispatcher, and the system looks in the buffer instead of relaying the request to the dispatch station. This allows dispatchers to pre-publish files and even serve aircraft when the dispatch station is no longer staffed.
When an ACARS client retrieves a file, it is completely up to the client what to do with it. Some files are suitable for display, others should be saved on a disk and fed into a flight simulator (such as FMS route files). ACARS itself cannot do this, so it depends on your client what you can do here, and usually also on the particular brand of flight sim.
Server Storage and Web Storage
If the central buffer of the ACARS server is used, the published files are erased after 24 hours. Dispatch stations therefore may want to refresh their files in time for their flights to pick them up.
An alternative publication method is to publish the same files on your own web site, and register the common URL prefix of all files with the ACARS server, based on your three-letter company code. This is a manual action by the ACARS server developer, so please contact me (address below) if you want such a URL registered.
The Connection Protocol
The file upload and download commands are sent to the server in the same way as all other ACARS "radio links". Connect to the Web server with the following URL (subject to change):
You need to supply a few data items with each request. You may use either the GET or the POST protocol, or both intermixed.
Just as for all other ACARS command URLs, you can use either GET or POST or a mix of the two methods to get your arguments across.
Upload example if you use a plain GET protocol URL:
Note that this example does not use proper URL encoding, though it tends
to work in most browsers. Please use whatever works for you. After this
command, the server file buffer holds a file
This file can be retrieved by:
For retrievals, there is no hard relationship between the "from" callsign and the file name, this is purely whatever your ACARS client wants to put there. The company code in "to" is relevant, to select the correct name space.
The file is always returned in simple hex-encoded ASCII, so you
can retrieve binary files this way. Every programming language has a
function to convert from hex to binary; PHP uses
To upload binary files, you need to use exactly the same method as for
text files, but with the
Typically, file names are related to a flight of the day (KLM2345.TOP for today's flight takeoff perfomance) or to a route (AMSLHR4.ROU for the fourth route from Amsterdam to London as used by this company). It is completely up to you and your simulator what is handy here. There is no standard.
|© 2023 Jeroen Hoppenbrouwers||For more information, mail to firstname.lastname@example.org|