Automated Test Equipment
Robert Gilchrist Huenemann, M.S.E.E.
(851) 635-0786
January 26, 2006
Between 1971 and 1973, I was the principal engineer for the Hewlett-Packard 9540 Transceiver Test System. I designed the hardware configuration for this system, and wrote the sample program to test a typical two way radio to EIA specs. My previous experience in RF and analog circuit design was helpful in this endeavor.
The 9540 used the then new HP 8660 RF signal generator, and HP was having some difficulty manufacturing this unit. Since the 9540 also included an HP 432 power meter and an HP 5326 frequency counter, I found it advantageous to write an automated test for the 8660. Eventually this grew into an automated self test for the entire 9540 system. This allowed me to quickly return defective instruments to the various HP manufacturing divisions, with a detailed listing of their failures.
Between 1973 and 1980, I was employed in avionics maintenance support at United Airlines. While there, I wrote programs for the Honeywell 2600 ATE systems. I developed a data acquisition system for recovering VOR (very high frequency omnirange) bearing angles from the Fourier transform of a digitized VOR signal. I developed another automated system for testing generator and bus control units for the DC-10 400 Hz power system, and yet another automated system for calibrating fluid pressure gauges and flow meters. I also developed a semi-automatic system for testing radar transponders. These systems were controlled by various desktop computers, including the HP 9826 and the Commodore PET.
From 1980 to 1990, I was employed at Wiltron (now part of Anritsu). I developed HP-85 test programs for the Wiltron 5600 Automated Scalar Network Analyzer, was involved in the development of the Wiltron 360 Vector Network Analyzer, and developed measurement routines for the Wiltron line of telecommunications test equipment.
In 1990, I joined Varian NMRI. It was apparent that NMR and MRI systems are ideally suited to an automated self test process. I developed these tests, which are now used on the Varian Inova, Mercury and InfinityPlus product lines. They incorporate thousands of test steps which verify the proper operation of every part of these complex systems. They are written in a Pascal variant with C language subroutines, and run on UNIX workstations.
The tests are semi-automatic in that they require an operator to make various system connections and to insert appropriate values of attenuators into signal paths. However, approximately half of the test steps are made with one single set of connections that includes every system signal path, such that this part of the test can be run repeatedly until interrupted. This portion of the test is typically run for 24 hours or more and has proven valuable in identifying intermittent failures.
At Varian, I also developed a small automated system controlled by a PC, using Visual BASIC and National Instrument parallel and IEEE-488 interface cards and drivers, for testing of PTS synthesizers, Highland Technology pulsed field gradient amplifiers, and RF amplifiers.
All of the above tests include an interface that allows the operator to stop on failures, to repeat tests for troubleshooting purposes and to enter information for system records. These records include a summary of system failures and a complete record of all system tests.
I have written test programs in several versions of BASIC, including Visual BASIC, the Honeywell ELAN language, the Varian version of Pascal, and C. I also have some FORTRAN and assembly language experience. I am comfortable with several operating systems, including UNIX. I have written fully automatic and semi-automatic tests as well as automated self test programs, based on the requirements of each particular situation.
Finally, I have incorporated DSP concepts such as spectral analysis, modulation domain measurement and band limited interpolation into most of the tests I have developed, thereby making it possible to use fewer instruments or to extend the capabilities of the instruments which were available.
If your only ATE resource is an instrument vendor like Agilent, Fluke or Keithley, you will be told nothing about the semi automatic or automated self test options. I would appreciate an opportunity to discuss your requirements, the architecture of your product and its suitability for fully automatic, semi automatic or automated self test.