Abbreviated Test Language for All Systems


Abbreviated Test Language for All Systems is a MILSPEC language for automatic testing of avionics equipment. It is a high-level computer language and can be used on any computer whose supporting software can translate it into the appropriate low-level instructions.

History

The ATLAS language was initially developed by an international committee of representatives from the airline industries, military services, avionics manufacturers, and automatic test equipment manufacturers. The goal of the committee was to design a standard English-like language that could be easily understood and used by both avionics and test equipment engineers. The result was the ATLAS language specification, published by ARINC.
The ATLAS language is oriented toward the Unit Under Test and is independent of the test equipment used. This allows interchangeability of test procedures developed by different organizations, and thus reduces costly duplication of test programming effort.
The first ATLAS specification developed by the international committee was published in 1968. The basic document has been revised several times.
An ATLAS implementation typically consists of an online compiler, test executive, and file manager and media exchange packages. ATLAS is run in TEX mode on test stations while testing electronic equipment.

Structure

A standard ATLAS program structure consists of two elements: preamble structure and procedural structure. The language makes extensive use of variables and statement syntax. An ATLAS statement consists of these fields:
,$
Sample ATLAS Statements:
000250 DECLARE,DECIMAL,'A1'$
000300 FILL, 'A1', 'NUM',
1, 5,
20, 87,
15, 12,
30, 18$
Comments may be included with a 'C' in the field.
These ATLAS statements apply a voltage to a pin and verify the presence and characteristics of a voltage at a pin:
...
010200 APPLY, AC SIGNAL, VOLTAGE-PP 7.5V, FREQ 3 KHZ, CNX HI=P1-1 $
...
010300 VERIFY,, AC SIGNAL, VOLTAGE-PP RANGE 64V TO 1V, SAMPLE-WIDTH 10MSEC,
SYNC-VOLTAGE 2 MAX 5, SYNC-NEG-SLOPE, MAX-TIME 0.5, GO-TO-STEP 400 IF GO, LL 0.5 UL 50,
CNX HI=P2-4 LO=P2-5, SYNC HI=P2-8 LO=P2-5 $
...

Applications

ATLAS has been used in the U.S. Air Force primarily on test stations for testing the avionic components of the F-15 Eagle, F-16 Fighting Falcon, C-5 Galaxy, C-17 Globemaster III, and B-1 Lancer. The U.S. Navy uses ATLAS-based programs for testing avionics systems of the P-3C Orion, UH-1Y Venom, AH-1Z Viper, SH-60 Seahawk, E-2C Hawkeye, F-14 Tomcat, F/A-18 Hornet, S-3 Viking, A-6 Intruder, EA-6B Prowler, AV8B Harrier, and V-22 Osprey. The U.S. Navy and Marine Corps used a version called Super Atlas for its AN/USM-484 hybrid test set test benches. The AN/USM-247 VAST was used by the Navy onboard aircraft carrier and shore stations. It has been used in testing the F-14, S-3, E-2, A-7 Corsair II, A-6, etc. VAST is considered by many to be the grandfather of modern avionics test equipment.
In the years that followed the cold war, ATLAS found uses on many dual-use aircraft for the U.S. and NATO, as well as commercial business, regional, and general aviation aircraft. ATLAS test program sets allow porting older programs to new hardware, providing some protection against hardware obsolescence. Although a standard, many adaptations, customizations, and flavors exist that impede full portability. Because most ATLAS toolsets are custom, on custom hardware, with a custom software load for the platform, it is not as prone to some types of issues that plague other languages that are more prevalent in the industry; the down side is that training is not available to the general public, so it also requires an extensive investment in personnel.
ATLAS generally can be configured to run "stand-alone", or "stand-alone monitored only" which can help limit many of the tampering and other concerns with mainstream commercial software. Other languages, such as BASIC, C/C++, Python, and Perl, are also used on commercial and military programs for testing of systems; ATLAS typically requires another computer system to either optically scan test results, or read a tape, disk, or locked memory stick/data key from a test station and then perform statistical analysis on test results for a variety of uses.

Subsets

Subsets include:

Implementations