基于PXIe接口的CoaXpress高速相机图像采集、回放

PXIe简介

PCI eXtensions for Instrumentation or PXI is a computer-based hardware and software platform for test and measurement systems. Developed in the late 1990s as an open industry standard based on the compact PCI (cPCI) computer bus, PXI provides a basis for complex, rugged, modular instrumentation systems. The PXI standard is governed by the PXI Systems Alliance (PXISA) which maintains and controls the evolution of the standard to insure interoperability of instruments from hundreds of vendors. PXI Express or PXIe is a subset of the PXI standard that replaces PXI’s parallel data bus with a high-speed serial interface. PXIe provides the most advantages for modular instruments like digitizers or arbitrary waveform generators which often need to transfer large amounts of data. For example, state-of-the-art PXIe products from Spectrum incorporate a fast interface that can stream at rates of up to 1.7 GB/s.
简单来说，PXIe就是在PCIe总线上做了一些扩展，扩展信号主要是为了满足高精度、高速、同步等测试测量应用。
下面一张图来自简仪科技网站，该公司目前是国内主要的PXIe系统提供商，从图上可以看出，PXIe实际上就是一台特殊的工控机，每个卡槽可以插入不同功能的板卡，组成一个复杂的系统。

CoaXpress简介

CoaXPress ( CXP ) 是为机器视觉应用中的高速图像数据传输而开发的数字接口标准，用于替代cameralink接口，可以提高更大的数据吞吐率、支持更高的相机帧速率。CoaXPress 主要用于数字成像应用，但也适用于通用数字数据的高速传输。CXP目前已经发展到了2.0，接口速率12.5Gbps/s

下图是Mikrotron公司的一款CoaXpress接口相机，借助CoaXPress接口，在1280*864尺寸下，可以提供高达2050fps的帧速