基于双指针环形缓冲区的数据采集系统设计

Design of Data Acquisition System Based on Dual Pointer Ring Buffer Area

为保证高速A/D采集的数据在传输给上位机时不丢失,在内存中开辟一段缓冲区,首尾相连,分别设置读、写指针,构成双指针环形缓冲区模型,并设计了数据采集系统软件架构和功能程序。采样程序将A/D结果写入缓冲区,写指针循环加1;主程序从缓冲区读出数据并传输,读指针循环加1。缓冲区被动态循环使用,有效地节省数据存储空间。通过ARM7LPC2148MCU和AD7606 ADC芯片构成数据采集系统硬件:50 kHz双通道同步采集时,环形缓冲区长度为16 Kbyte字,连续采集和传输32 K点不丢失数据,保证了采样速度。实际应用证明:该数据采集系统具有硬件原理简单,软件架构清晰,占用内存小,开放性及可再开发性好等优点。

To ensure the data of high speed A/D acquisition isn＇t lost during transmission to host computer,the dual pointer ring buffer area was setted including a buffer in memory, end to end, two pointers of reading and writing.Software architecture and functional routines of the data acquisition system were designed.Sampling task wrote A/D results to the buffer,write pointer round increased one. Main task read data from the buffer from the buffer, read pointer round increased one. The buffer was repeatedly used which effectively reduce the data storage space.By using the data acquisition system hardware based on ARM7 （LPC2148） MCU and AD7606 ADC, under dual-channel synchronously acquiring 32 K points at 50 kHz sampling rate, the data was without lost when the length of ring buffer is 16 K word, thus ensuring the sampling rate.The practical application proves that the data acquisition system has the advantages of simple hardware principle, scientific and clear of software architecture, Small memory, good openness and exploitability.