David Batet - 6TL
Fulgencio Buendia - 6TL
Lluis Angles - 6TL
Jordi Peguero - 6TL
Raimon Pousa - 6TL
Enrique Osorio - 6TL
Ángel Marín - 6TL
Description of the DUT
The DUT is a DVB-S set-top box with the typical device features, including RF input, RF output, HDMI generation, RCA and SCART connectors for composite video broadcast signal (CVBS), RGB, audio, and infrared, for TV sets and VCRs. The DUT also features a USB port for recording. As explained, our product under test is a panel of two set-top boxes.
Test Solution Description
We based our solution on the modular 6TL-33 FastATE test handler, which is the latest generation solution for high-performance and flexible production lines from National Instruments Silver Alliance Partner 6TL Engineering. It features dual-conveyor technology, including automatic bypass during testing, a high-pressure solution for reliable ICT >3,000 kg, and advanced maneuver management (diversity for same product can be produced without any configuration change in the line). We can connect up to eight 6TL-33 handlers together to form a test production line.
With the 6TL engineering concept, every station works independently but cooperatively, and the stations are linked through the conveyors with Ethernet and extended Surface Mount Equipment Manufacturers Association (SMEMA) connectors, with a controller area network (CAN) for machine cooperation and supply for automatic bypass in case of failure or maintenance. We use intermachine communication and LabVIEW shared variables to manage DUT logistics and share test data.
An NI PXI rack protected by an uninterruptible power supply and touch panel manages the station control. Every station includes room to integrate 19 in. rack-and-stack instruments as well as a power management module. Conveyors transport DUTs through the test stations, and the width of the conveyor belts is automatically adjusted just after the operator has placed the fixture. When a DUT gets inside the 6TL-33 test handler, it is scanned. Based on the result, the system decides which station can perform the test. The dual conveyor makes the trip between stations possible since any test handler in testing condition, maintenance, or failure condition will be bypassed. The bypass enhances reliability since it helps avoid undesirable production down times.
When a DUT gets inside a test handler, an automatic heavy pressure mechanism lifts it to top position and against the pusher plate to provide a reliable connection. We need 2N per test probe, which is high pressure when working with about 1,200 test points. At the same time, the second conveyor is placed in the inlet position to activate the bypass so that another DUT can travel “through” the line. The lifter can work in different height positions (ICT, FCT, or high potential) to match the specific requirements of an application. This lifting device is made with a high-quality servomotor that provides the precise and fast reactions required for this kind of application.
Every 6TL-33 handler features a mass interconnect receiver for fixturing connection. Every fixture includes custom DUT accessories, probes, and wiring to connect the DUTs to instrumentation, which is required to achieve the requested testing. The mass interconnect solution implemented in the 6TL-33 test handler makes fixture changeover easy. We based the tester switching on modules that directly connect to the mass interconnect receiver (YAV modules).
We also implemented other functions needed in our test execution in these modules, including pneumatic switching and LED analysis. We directly implemented high-end instrumentation on the PXI rack, which provided the power and flexibility required to deliver future-proof video and audio analysis.
YAV modules cover typical functions needed when developing an ICT/FCT system and complement NI modular instrumentation. All the modules from 6TL are CAN bus controlled with a PXI CAN board installed in the controller and 6TL Phi6 drivers for LabVIEW. In addition to the LabVIEW drivers for all 6TL modules, the Phi6 software package from 6TL includes virtual instruments for each 6TL module and a user interface (UI) to control the ATE.
We programmed the UI with LabVIEW, and it helps the operators do their jobs without programming knowledge because it automatically detects the fixture and the test sequence to execute. The operator just needs to start the test cycle to see a display in the Phi6 UI of all the information, including the test progress or the number of failed and passed DUTs.
The 6TL-33 test handler features a Data Matrix reader that identifies each device arriving. The code read goes into a file that is shared with all 6TL-33 handlers within the line. When a handler is available in the system, DUTs get into the line to reach the assigned handler. When the DUT reaches its destination, it stops and is lifted to the testing position or a bypass conveyor is enabled for the next DUT.
Each station executes the same test in parallel, sharing available resources. The FCT checks that all signals generated—HDMI, CVBS, and audio—fall within specified limits and it generates UART and infrared control signals and checks that the DUT responds properly to them. Test results are stored in the reports that NI TestStand test management software automatically generates.
We based the audio and video test on studying the video formats and synchronisms, the RGB signals in a color bar test pattern, and the frequency and amplitude of the audio signals. The NI instrumentation performed this job perfectly. It was easy to start operating with this module. Setup, programming, and executing operations were all fast. Additionally, the controller empowered the test engineer to choose between a lot of immediate measurements over the signal, and provided good processing performance.
Our solution guarantees quality for the production of the product by covering all of the test specifications. The cycle time meets the needs of the production line because it can test four DUTs at a time in the FCT. NI products gave us the right environment to develop the application quickly and easily.