下表列出了构建远程电缆时需要的扩展端口引脚分配。电缆之间的所有连接都是点对点的，即一端的针脚2到另一端的针脚3，针脚3到针脚3，等等。表B-1。扩展端口引脚分配引脚号信号名称功能16 DIODT I/O串行数据正极17 DIODT/I/O串行数据负极24 DIOCLK I/O串行时钟正极25 DIOCLK/I/O串行时钟负极20 DRSEL远程选择正极21 DRSEL/远程选择负极12 DRPERR奇偶校验错误正极13 DRPERR/奇偶校验错误负极8 DRMRUN远程运行正极9 DRMRUN/远程运行负极2DFRAME循环帧正极3 DFRAME/循环帧负极1 FGND帧接地用于电缆屏蔽7 0V逻辑接地I/O扩展总线终端当两个或多个底板在扩展系统中连接在一起时，I/O扩展总线必须正确端接。I/O总线必须端接在设备的后一个基板上
The following table lists the expansion port pin assignments you will need when building remote cables. All connections between cables are point-to point, that is, pin 2 of one end to pin 2 of the opposite end, pin 3 to pin 3, etc. Table B-1. Expansion Port Pin Assignments Pin Number Signal Name Function 16 DIODT I/O Serial Data Positive 17 DIODT/ I/O Serial Data Negative 24 DIOCLK I/O Serial Clock Positive 25 DIOCLK/ I/O Serial Clock Negative 20 DRSEL Remote Select Positive 21 DRSEL/ Remote Select Negative 12 DRPERR Parity Error Positive 13 DRPERR/ Parity Error Negative 8 DRMRUN Remote Run Positive 9 DRMRUN/ Remote Run Negative 2 DFRAME Cycle Frame Positive 3 DFRAME/ Cycle Frame Negative 1 FGND Frame Ground for Cable Shield 7 0V Logic Ground I/O Expansion Bus Termination When two or more baseplates are cabled together in an expansion system, the I/O expansion bus must be properly terminated. The I/O bus must be terminated at the last baseplate in an e
