Any subsequent external commands, if they are run in the default SYSTEM environment, will direct their output to the default FIFO. (first-in-first-out).
任意接下来的外部命令，如果他们是在默认的SYSTEM环境下运行，将把它们的输入定向到默认的FIFO(先入先出，first - in - first - out)。
2
The simulation results show this control system has good dynamic property and negligible vibration, and efficiently makes the output current of direct motor trace the intent current.