基于FPGA和Modbus协议的通用数据采集装置设计

Design of Data Acquisition Unit Based on FPGA and Modbus Protocol

针对分布式测控系统中以数据采集需求为主的场合,提出了一种基于Modbus协议和FPGA的通用数据采集装置设计方案。该数据采集装置由多通道模数转换器、FPGA主控芯片、RS485转换芯片、隔离电路等组成,FPGA负责对Modbus协议进行解码和编码,并根据系统主机的配置信息控制模数转换器的转换过程以及数字量I/O口的输入输出。实际使用表明,该装置具有结构简单、组网方便和稳定性及兼容性好等优点,能很好地满足对成本敏感的分布式测控系统的需求。

For the data acquisition needs-based distributed control system, this paper proposed a general data acquisition de- vice based on Modbus protocol and FPGA. The data acquisition device consisted of multi-channel ADC, FPGA main control chips, RS485 converter chips, buffer circuits and so on. FPGA was responsible for decoding and encoding the Modbus protocol and con- trolling the conversion process of ADC and the input and output of digital Ⅰ/O port based on the configuration information of the host. The test results show that the device has the advantages of simple structure, convenient networking, stability, good compatibili- ty and so on, thus meeting the demands for the cost-sensitive distributed measurement and control system.