Development Of ATE Reconfigurable Instrument Resources With Multiplex Terminals

ATE which is multifunctional and small-sized is the trend of development to the automatic test equipment at modern times. The traditional instrument needs the general test instrument resources accompanied with specialized TUA( the interface adapter for test). With the increasing models of equipment, more and more special test interface adapters are needed. This results in the rapid expansion of the volume of the test equipment. To solve this problem, this subject designed a kind of instrument resources with reconfigurable and multifunctional terminals. This module has a good number of test channels, single channel with mult-function and large measuring range.The development of the instrument device has an important value of application.In order to realize universalization and miniaturization, the module is designed with small devices in architecture of DSP+FPGA, controlled by logic based on Avalon bus. There are 50 input channels, 8 output channels and storage of 1GB on the circuit board of 3U size with measure interface of CPCI. The 48 input measure channels of designed module is integrated with more than one functions. In addition,these input channel has lagre measure range each. It is designed as follow:(1)The 32 channels for analog signal and digital measurements are realized by sharing AD conversion circuit.When digital measurement mode is selected, the software will transform AD results to digital results; the large measure range of ? 110 V is realized by designing front-end circuit with difference amplifier, which can measure high voltage; the 3 channels for measuring frequency share test pins with AD conversion circuit. It is decided to be used by opening electric relays, therefore to solve the compatible question.(2)To realize 16 channels for measuring resistance, AC and DC signals, the transformable function circuit controlled by a group of electric relays; in order to broaden the range of measurement to ? 400 V further, the digit DMM chip with high input range controlled by software and logic. DDR3 whose storage is expanded at depth is designed to realize storage of big capacity under control of software program.In addition, this design also designed DSP program and PC program. DSP program is designed to analyse and carry out the command send from the host computer. To solve the control problem of function setment cross combination of all channels, the configuration table of instrument resource is employed in the DSP program. DSP program will inquiry the configuration table to set up functions and get result. At the time, the driver function is designed as mode setment to channels, and communicate with DSP by shsking hands. The virtual instrument interface can save the configuration table by user.In the end, the module designed is test to show whether it works well, and it is also test in the auto test system. The test results show that the instrument is designed reasonbly.The instrument module itself is proved out to be stable and reliable, thus meet the requirement.