Design Of 100m Two Channels Universal Counter Lxi Module

LAN extension for instrumentation bus was built on the base of several industry standards, for example, Ethernet, PTP, VXI, IVI and so on. LXI centralized all the merits of standards mentioned above, and formed features of its own. LXI had taken the timing, trigger, cooling, EMC into consideration, which were important in the scope of instrumentation. LXI was the ideal choice for building the next generation measure and test platform. In the paper, universal counter LXI C class module was designed, and this module was one of ideal choices for measurement module for real-time and high speed measurement.After analyzing the demand, the sub function circuit was compared and argued, It was comprised of LXI interface circuit, measurement logical design circuit, signal shaping circuit and trigger control circuit part, which could test the following parameters of the input signal, including period, frequency, magnitude, pulse width and so on. And its measurement analog bandwidth could be up to 100M, its measurement time resolution could be up to 10ns. In the design of hardware, signal shaping circuit, signal conditioning, high speed measurement logic and LXI bus interface circuit were introduced and discussed especially, key devices and specific circuits were introduced and explained, driver program for LXI interface was introduced finally.The module had two high speed symmetric channels, each channel could complete measurement independently, and both two channels'scope of input signals ranged from +/-30mV to +/-50V. CPLD was used to realize the measurement function. ARM was taken as the control centre, which controlled the cooperation among different function modules.