Phase Matrix produces six VXI modules, the 1230A and 1231A frequency counters, the 1140B and 1141B upconverter/synthesizers, the 1313B microwave downconverter, and the 20309 local oscillator. High-performance, tight coupling of instruments, flexibility in system configuration, and reduced size through resource sharing are benefits inherent in VXIbus architecture that are ideal for automatic test and measurement systems.