VERTA Integrated Optical Power Management and Switching Instrument

Transcription

1 VERTA Integrated Optical Power Management and Switching Instrument For Defense and Aerospace Automatic Test Equipment (ATE) Tony Erwin Teradyne 700 Riverpark Drive North Reading, MA February

2 Background Defense and Aerospace assemblies (WRA/LRU/LRM/SRA/SRU) have broadly adopted optical transmission for high-speed serial bus interconnections, and this trend is rapidly expanding. Planes, ships, and land-based vehicles benefit from the speed, noise immunity, and reliability of optical communication. Assemblies employ buses such as: Fibre Channel, Ethernet, Serial RapidIO, Serial FPDP, PCI Express, Xilinx Aurora, and Altera SerialLite at speeds up to 10 GB/s through potentially dozens of fiber-optic ports. There is a relatively small range of power at the fiber-optic port receiver that will provide satisfactory performance. There are significant variations in the transmitter output power and receiver sensitivity of each UUT port, and the degree of attenuation within the fiber path between assemblies. Requirements vary, but a common characteristic is that optical power must be within a narrow window in order to ensure reliable communication. ATE must interconnect instruments to each UUT port and be capable of Optical Power Management or inline parametric optical test, which ensures reliable, error-free communication. Without ATE Optical Power Management, out of specification units will pass, producing erroneous No Fault Found test results, intermittent weapon system operation, and assemblies that circulate in the repair cycle. VERTA Overview Teradyne s VERTA Instrument enhances capabilities in ATE to test the integrity of optical links and to switch various fiber optic and copper, high speed, and serial digital UUT interfaces to multiple test instruments. Designed for Defense and Aerospace ATE, VERTA Optical Power Management verifies each optical UUT port with inline optical parametric test. It also contains a powerful physical layer switch matrix to provide concurrent non-blocking interconnections to multiple serial bus test instruments within the ATE. VERTA ensures reliable error-free bus communication and interoperability for optically networked military weapon assemblies. VERTA test capabilities minimize costly intermittent and No Fault Found test results. VERTA has been designed with several features to address all key ATE requirements needed for fiberoptic link testing in military Depots and Defense and Aerospace Factories; February

3 Flexibility - Configurations for a wide range of optical port counts, independent of bus protocol and speed Optical Power Management Inline parametric validation of each optical link to ensure insystem assembly interoperability Link Integrity Test - Fiber-optic link test with protocol transparent bus data switching enables ATE to ensure error-free interoperability of weapon system assemblies Concurrent & Parallel Test Simultaneous test of multiple UUT ports and multiple assemblies Comprehensive Support - Proven technical and logistics support over the program life cycle that avoids expensive obsolescence VERTA instruments consist of a central infrastructure called a Foundation configured with I/O Modules that interface with the bus instrumentation and the UUT. Multiple Foundation models support a large quantity of optical ports in a space-efficient package. Foundations provide semiconductor-based switching to interconnect ports of I/O modules, plus power, cooling, and an LXI interface. The I/O Modules provide a range of capabilities, including: switching to connect UUT ports to bus instruments, concurrently operating UUT buses, multiple assemblies tested in parallel, and Optical Power Management consisting of accurate output power control and input measurement. VERTA Flexibility Flexibility addresses ATE configuration demands and the ability to manage the broad range of optical bus types, speeds, port counts, instrumentation, test methodologies, and future requirements. A factory making assemblies with modest port counts may only need a basic 2-slot VERTA Foundation with one or two I/O Modules. A depot supporting multiple weapon systems or a factory testing assemblies in parallel may require a large VERTA Foundation housing up to 10 I/O Modules and 160 bidirectional I/O ports. For all configurations, VERTA maintains a high port density that minimizes the overall test system footprint. Figure 1: VERTA Foundation and Switch Modules February

4 The Foundation employs a semiconductor crosspoint matrix that combines with the I/O Modules to convert electrical matrix signals to optical interface ports. The result is a Physical Layer Switch, with interconnections that are independent of bus protocol and speed, able to connect any port input to any port output. Alternatives to VERTA typically use limited, single-protocol, point-solution switches that result in unique hardware for each bus type, increasing the cost of integration, training, programming, and support. VERTA flexibility addresses multiple protocols and speeds in a single instrument, avoiding hardware proliferation. While VERTA provides the connections to UUT ports, bus instruments are called upon to test the functionality of each port. Configurable Teradyne High Speed Subsystem (HSSub) instruments are ideal, addressing the full range of bus protocols and speeds, tailored to the capabilities of the UUT. Instruments must check port operation, and then repeat these tests while VERTA performs worst-case optical power tests. The basic Multi-Protocol Switch Module provides full switching capabilities and I/O provided by standard Small Form-Factor Pluggable (SFP/SFP+) transceivers. I/O is typically optical, but electrical support is also available. While fixed optical power of the transceivers is appropriate for interfacing with the bus instrumentation, UUT I/O are best served by I/O modules that provide Optical Power Management. VERTA Optical Power Management Figure 2: VERTA Multi-Protocol Switch Modules VERTA Optical Power Management capability provides the accuracy to ensure that assemblies will interoperate free of communication errors within the weapon system. There is a relatively small range of power at the receiver that will provide satisfactory performance. There are significant variations in the optical output power and receiver sensitivity of each UUT port, and the degree of attenuation within the fiber path between assemblies. In addition, all of these parameters can change with age. In the weapon system, diagnosis of an operational or self-test failure cannot differentiate between a fault in the fiber optic path, or within the connected assemblies. Multiple suspect assemblies are typically removed, and it is the responsibility of the ATE to accurately determine their condition. Without ATE Optical Power Management, out of specification units will pass, producing erroneous No Fault Found test results, intermittent weapon system operation, and assemblies that circulate in the repair cycle. February

5 The Optical Power and Switch Module provides switching, plus power control and measurement. In place of the fixed-power approach, each power-managed port employs high-capability optical components. Each output channel converts electrical signals from the Foundation crosspoint matrix to an optical source, followed by a programmable attenuator and power meter. The input channel measures the optical power and converts light to electrical signals for the VERTA matrix. The result is accurate output control and input measurement over a 10dB power range, sufficient for many applications. Figure 3: Optical Power and Switch Module with individual port power control and measurement capability Some assemblies are designed to operate over an even wider power range to compensate for the variation in attenuation of complex or inconsistent optical interconnections, or the inevitable ageing of components. This requires the UUT and instrumentation to operate accurately at low output and input power levels. The 8-Port Wide-Range Power Module provides an optical-to-optical capability with a 25dB power range for measurement and output control. Typically, the eight I/O ports are optically jumpered to eight ports of a 16-Port Optical Power and Switch Module for the full flexibility of VERTA matrix control. Figure 4: One Port of a Wide-Range Optical Power Module February

6 VERTA Link Integrity Testing Link Integrity Test is the combination of Optical Power Management and data-intense UUT stress testing, ideally implemented with VERTA and highly configurable HSSub bus instrumentation. HSSub Apps tailor the instrument hardware and adapt to UUT capabilities, provide basic bus operations for the parametric optical tests, and exchange huge quantities of data while monitoring potential communication errors. A UUT designed for Bit Error Rate Test (BERT) can interact with HSSub. Link Integrity test with VERTA and HSSub is the best combination for ensuring error-free operation of assemblies when operating within the weapon system. VERTA Concurrent & Parallel Test Figure 5: Typical VERTA ATE Implementation Along with increasing UUT I/O port count is the requirement that multiple ports operate concurrently. Advanced, highly capable bus instrumentation and simultaneous connections are necessary. VERTA has the unique capability to connect any number of ports carrying buses of various types and speeds without conflict because it employs a non-blocking full crosspoint matrix. Parallel testing of multiple assemblies is beneficial with long test times, or if production volume is high. Parallel test reduces both labor and equipment costs. The robust VERTA switching capability supports testing multiple assemblies in parallel, each of which can have multiple concurrently operating buses. Both concurrent and parallel test benefit from scalable HSSub instruments that operate simultaneously and autonomously, free of shared resources. February

7 VERTA Long-term Supportability VERTA supportability is built on over 40 years of Teradyne experience in Defense and Aerospace test, with a reputation for superior technical and logistics services that extend over long product lifecycles. Conservative design, high-density packaging, and exhaustive product testing maximize Mean Time Between Failure (MTBF) and minimize Mean Time to Repair (MTTR). Unlike equipment designed for rapidly changing commercial applications, VERTA provides Defense and Aerospace ATE with a stable solution, the required long-term support, and a stable solution that avoids expensive obsolescence. Summary VERTA enhances capabilities in Defense and Aerospace ATE to test the integrity of optical links and to switch many high-speed, serial digital UUT interfaces to multiple test instruments. VERTA Optical Power Management verifies each optical UUT port with inline optical parametric tests. It provides a high-speed digital switch matrix with concurrent non-blocking interconnections to multiple serial bus test instruments. VERTA compliments the highly configurable HSSub bus instrumentation, which provides basic bus functionality test and data-intense UUT stress testing to verify Link Integrity. The goal of VERTA is to ensure reliable error-free bus communication and interoperability for high speed and optically networked military weapon assemblies in order to minimize costly intermittent and No Fault Found test results. February