本例程演示了PC机和智能型仪表如何通过RS485接口进行通信。仪表采用专家自整定PID调节器，该仪表的通讯协议已经在例程代码中作了详细说明。-This routine demonstrates how PC and intelligent instruments through the RS485 interface to communicate. Instrument using the self-tuning PID regulator, the instrument of the comm