Abbreviated Test Language for All Systems
Abbreviated Test Language for All Systems (ATLAS) 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.
The ATLAS language was initially developed by an international committee made up 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 Aeronautical Radio, Inc.
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.
The ATLAS programming language incorporates an online compiler (OLC), Test executive (TEX or Test Exec), and file manager and media exchange (FMX) packages. Test executive is the mode ATLAS is run in on test stations while testing electronic equipment.
A standard ATLAS program structure consists of two elements: preamble structure and procedural structure. The ATLAS programming language makes extensive use of variables and statement syntax. An ATLAS statement consists of a flag field, statement number field (STATNO), verb field, field separator, variable field, and statement terminator. Each and every ATLAS statement is terminated with the currency symbol ($).
ATLAS statement structure
A standard ATLAS statement: | F STATNO | | VERB |, | VARIABLE FIELD | | $ |
Sample ATLAS Statements:
000250 DECLARE,DECIMAL,'A1'(4)$ 000300 FILL, 'A1', 'NUM', (1) 1, 5, (2) 20, 87, (3) 15, 12, (4) 30, 18$ C AN ATLAS COMMENT HAS A 'C' IN COLUMN 1 AND ENDS WITH A DOLLAR SIGN $
Sample ATLAS statements to apply a voltage to a pin (stimulus) and verify a 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, (VOLTAGE-AV INTO ‘VAVG’), 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 $ ...
ATLAS is used in the 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 or has used 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 US Navy and Marine Corps used a version called Super Atlas for its 484 HTS test benches going back at least to 2000. AN-USM-247 VAST Versatile Avionics Shop Test was used by the US Navy onboard aircraft carrier and shore stations. It supported F-14, S3, E-2, A-7, A-6 et al. 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 US, NATO, as well as Commercial, Business, Regional, and General Aviation Aircraft. ATLAS Test Program Sets (TPS) allow porting an older code base to new hardware, providing some insurance from hardware obsolescence. Although a standard, many adaptations, customizations, and flavors exist that impede full transportability. As most ATLAS toolsets are custom, on custom hardware, with a custom SW load for the platform it is not as prone to some types of issues that plague other languages that are more prevalent in industry—the down side is that training on this is not available to the general public, and also requires an extensive investment in personnel. It 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 commercial software such as Apple, Microsoft, Linux, and other commercial/free 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.
ATLAS can be quite challenging to implement on newer more complex systems as, these can also involve many sub-contractors, and equipment vendors. However, the cost of re-writing a large base of existing TPS's can be a daunting task as well.
No open source versions of ATLAS currently exist, although that could make a good project for a university.
ATLAS-AN/USM-410 (RCA EQUATE)
C/ATLAS-IEEE-716-1982, 1985, 1989, 1995
TYX (now Astronics) created a COTS ATLAS compiler, Integrated Development Environment (IDE), and run-time system that ran on the original IBM PC and was updated for all flavors of Windows called Professional ATLAS Work Station (PAWS).
Lexico made converters that would take ATLAS code and convert to run under HP BASIC. These were popular with McDonnell Douglas, Boeing, Honeywell, etc.
Grumman made an ATLAS compiler for their IFTE V3 and V5 test stations.
General Dynamics made a compiler for their F-16 test station.
RCA developed a compiler for their EQUATE testers.