标准的RS232串口为25针的接口，我们的pc上常用的是9针的串行接口省略了一些引脚:设备侧为25针母插:RS232串口引脚定义PinNameITU-TDirDeion1GND101Shield Ground2TXD103Transmit Data3RXD104Receive Data4RTS105Request to Send5CTS106Clear to Send6DSR107Data Set Ready7GND102System Ground8CD109Carrier Detect9--RESERVED10--RESERVED11STF126Select Transmit Channel12S.CD?Secondary Carrier Detect13S.CTS?Secondary Clear to Send14S.TXD?Secondary Transmit Data15TCK114Transmission Signal Element Timing16S.RXD?Secondary Receive Data17RCK115Receiver Signal Element Timing18LL141Local Loop Control19S.RTS?Secondary Request to Send20DTR108Data Terminal Ready21RL140Remote Loop Control22RI125Ring Indicator23DSR111Data Signal Rate Selector24XCK113Transmit Signal Element Timing25TI142Test Indicator原文链接：http://www.eeworld.com.cn/qrs/article_2016102931430.html