基于CAN总线的运动控制通讯系统设计

数字量驱动的运动控制要求通讯系统具有良好的实时性和可靠性。设计了一种基于CAN总线的多节点多通道的运动控制通讯系统,以FPGA为节点控制器,通过SJA1000收发运动控制数据,并行发送到各通道驱动器的数模转换器中。FPGA模块由Verilog HDL编写,通过参数传递和生成块的方法简化代码,提高系统的可移植性,移植时只需改变两个常量值即可适应各个节点不同的通道数和位宽。实验表明,通讯系统每帧耗时约120us,最高帧频可达8.5kHz,误码率低于10^-8,实时性和可靠性较好。

Design of communication system for motion control based on CAN bus

Communication system in motion control driven by digital signal is required a good real-time performance and a high reliability. A motion control communication system with multi-node and multi-channel is designed based on CAN bus. The system takes FPGA as the node controller, sends and receives data of motion control through SJA1000, and sends the data to each digital-analog converters in parallel. The module of FPGA is written by Verilog HDL, and a method of parameter passing and block building is used to simplify the code and increase the portability, which makes the module can adjust to the node with different numbers of channels and data width only by modifying two parameters. Experiment shows that communication takes about 120 us per frame, and its highest frame frequency can be up to 8.5 kHz, while the error rate is lower than 10^-8, which indicates a strong real-time performance and great stability.