Electronics now plays a dominant role in virtually every product from tablets and smart phones to TVs and games to computers, airplanes, and military weapons systems. These electronic systems have become increasingly more complex with every passing day. Their circuit density and speed factors increase at seemingly exponential rates. As reliable as these systems are, from time to time they malfunction. Whereas years ago such a malfunctioning system could be repaired by a technician using manual instrumentation, today this is impossible.
Today the use of a sophisticated electronic testing system, commonly referred to as ATE (Automatic Test Equipment), is an absolute must. ATE ascertains whether an electronic system, subsystem, module, or printed circuit board is operating correctly and, if not, identifies what part of the unit is faulty and should be removed and replaced.
ATE has many uses during the life of an electronic product or system. First it is used during the product build cycle on a production floor. The usual scenario is for ATE to test the incoming Integrated Circuits (ICs) used to populate an assembly commonly referred to as a Printed Circuit Board (PCB) or module. A different type of ATE then tests the PCB. When a number of PCBs are assembled into a subsystem or black box, again ATE is utilized. Finally, if a number of subsystems are assembled into a system, once again ATE is used to ascertain proper functioning.
Once a system (e.g., computer, aircraft, medical electronics, weapon system) is in use, ATE must again be employed when the system malfunctions. Usually ATE, which is either built into the system or "stands alone," ascertains if the system is functioning correctly and, if not, identifies which subsystem is faulty and thus should be replaced. The faulty subsystem must then be tested on the same or different ATE to identify which of its PCBs or modules is to be replaced. Finally, that PCB or module must be tested to determine which IC or ICs are to be replaced.
In short, ATE has become a total necessity in today's increasingly complex, electronics-dominated world. Without ATE, electronic systems can neither be manufactured nor maintained.
Available Types of ATE
Some ATE systems are specifically designed for one of the testing niches discussed above (e.g., PCB testing on the production floor, subsystem testing in the maintenance environment, etc.). Some are aimed only at the commercial sector and others only for the military market. Some are for fixed installations and others are portable in nature. Most have a rigid structure which qualifies them only for a specific testing application and which makes it difficult for them to cope with evolutionary changes with time in the suite of units to be tested. The same rigid structure also hinders this type of ATE if new products with some different test requirements were to be introduced into the picture.
Some modern ATE, however, utilizes an open architecture for both its hardware and software. This approach has numerous advantages including the following:
- The flexibility realized allows this type of ATE to be used in virtually any test situation in the manufacturing or maintenance environments.
- The Unit Under Test (UUT) suite may physically be hybrids, boards, modules, subsystems, or systems.
- Initially, the user need procure only the test assets required to accommodate his or her UUT suite as currently identified; this keeps the initial cost low.
- The test spectrum may encompass any combination of digital, analog, RF, and/or Electro-Optical (EO) test capability.
- Additional test assets may be added with ease if test requirements change with time.
- The entire spectrum of digital, analog, RF, and EO test capability functions under a single, coherent ATE operating software system.
- The modularity and open architecture of both hardware and software assets are upgradeable with industry advances over time.
The hardware assets of a particular ATE system are usually defined so the system can test a particular suite of UUT. The test or applications software is the mechanism by which the ATE assets are utilized in a logical sequence to test a particular unit in the suite. In other words, each different type of UUT will have its own, individual test program matched to its unique test requirements.
The creation of test programs is a significant cost factor in the use of ATE. Modern ATE operating software must include numerous features so as to minimize this expense. Some of these features include:
- Industry standard operating environment such as Windows™
- Rapid, incremental test program code generation
- Fast binary execution to optimize test system throughput
- Easy and rapid test program edit and debug
- Extensive, user-friendly diagnostics to quickly and accurately identify UUT faults
Often the term TPS is used in conjunction with ATE applications software. TPS stands for "Test Program Set" and consists of the test program itself, any necessary cabling and/or adapter between the ATE and UUT, and appropriate documentation. If an ATE system provides flexible switching of its test assets, the need for complex adapters is minimized. However, some older ATE with rigid architectures require numerous and costly adapters due to their lack of flexibility. There is one TPS for each unique type of UUT.
The Test Challenge of Today
The use of ATE is absolutely essential in order to be competitive in today's marketplace. Even with the help of ATE, formidable challenges are faced:
- The product test requirements are typically many and varied.
- These requirements will likely change with time.
- The total test cost must be held to an absolute minimum.
- Rapid test program development is of utmost importance.
- Test execution speed must be optimized.
The Optimal test Solution
- The Benchtop Reconfigurable Automatic Tester (BRAT) family of test equipment is designed to answer today's most pressing challenges.
- The BRAT spectrum encompasses any combination of digital, analog, RF, and EO test capability, and the units to be tested may be hybrids, boards, modules, subsystems, or systems.
- The open hardware and software architecture based on industry standards (VXI, PXI, PXIe, IEEE-488, Windows™, etc.) provides the most cost-effective initial configuration and yet allows for future expansion to meet changing needs.
- The BRAT embodies a fully integrated, consistent turn-key software system regardless of the test capability mix.
- State-of-the-art program development tools and procedures are provided, edit/debug is easy and rapid, throughput is maximized from every aspect, and the latest in fault diagnostics are fully integrated.
BRAT TCASE software features include:
- Digital, Analog, RF, and EO testing under a single, coherent software system
- Industry Standard Operating Environment (Windows™)
- Upgradeable with industry advances
- Optimized Test Program Development
- Fast, efficient code generation
- Rapid binary-oriented execution
- Extensive debug features
- Extremely rapid compile and execute times
- Easy and rapid edit/debug capability
- Guided probe and fault dictionary diagnostics
- Data logging, analysis, and networking
BRAT provides the following capabilities:
- Open architecture built on industry standards
- Testing of hybrids, boards, modules, subsystems, and/or systems
- Digital capability to 50 MHz
- Analog from DC to 250 MHz
- Universal analog switching
- RF/microwave to 20 GHz
- RF/microwave switching
- Integrated automatic self test
Test System Features
- BRAT technology is state-of-the-art today and, due to its open architecture, can be modified and upgraded to remain state-of-the-art as customer requirements change, industry standards evolve, and new instruments and software modules appear.
- Non-proprietary hardware and software is employed and the open architecture accepts new hardware and software from many vendors.
- As the test system is enhanced with time, existing TBASIC test programs remain valid.
- The switching subsystem allows stimuli and measurement devices to be applied to the unit/device under test with maximum flexibility and full accuracy, thereby drastically simplifying interface test adapters.
- BRAT may be linked into a user's network providing total connectivity.
- Both the size and the cost of the system are fractions of traditional ATE.
Test System Benefits
Most customers strive to minimize their total test cost which is composed of various factors:
- Initial tester price
- Ease of test program preparation
- Tester availability
BRAT is designed specifically to minimize the total cost to its users:
- The open architecture allows for the lowest cost configuration custom tailored to the application, with the ability to grow indefinitely as user requirements change with time.
- Throughput is maximized via:
- High-performance processor
- Use of high speed buses
- Binary code execution
- Optimized plug and play software drivers
- Test Program preparation and debug is optimized via:
- Test Program Development oriented language
- MS Windows™ Environment
- Automatic test pattern generators/simulators
- Fault dictionary and guided probe diagnostics
- Rapid on-line edit and debug
- BRAT availability is maximized via:
- High test system mean-time between failures
- Efficient self test which fault isolates to a replaceable module
- Easy replacement of any faulty module