详细讲述了RS232，RS485，RS422电平间的不同，及各电平的特点等问题。

􀂄 The communication protocol will be downloaded to the model along with screen data, PLC needn’t compile communication program. 􀂄 Can connect with nearly all PLCs popular in the current market, such as Mitsubishi FX series、Omron C s

串口编程，串口在GUI设计中的应用，用于RS232、RS422之间的通信-Serial programming, the serial port in the GUI design for RS232, RS422 communication between