输入端的一次电路与二次电路之间，采用光电耦合隔离。二次电路带RC滤波器，以防止由于输入触点抖动或从输入线路串入的电噪声引起PLC误动作。       若在输入触点电路串联二极管，在串联二极管上的电压应小于4V。若使用带发光二极管的舌簧开关，串联二极管的数目不能超过两只。       另外，输入接线还应特别注意以下几点：       (1)输入接线一般不要超过30m。但如果环境干扰较小，电压降不大时，输入接线可适当长些。       (2)输入、输出线不能用同一根电缆，输入、输出线要分开。       (3)可编程控制器所能接受的脉冲信号的宽度，应大于扫描周期的时间。       2.6 输出接线       (1)可编程控制器有继电器输出、晶闸管输出、晶体管输出3种形式。2416 LAM RESEARCH RF CONNECTOR MODULE 853-800749-0018993 APPLIED MATERIALS MOUNT ASSY BOWL W/PASS-THROUGH 0010-4736713648 APPLIED MATERIALS CBL ASSY, AC POWER, IPUP, 300MM ENDURA  0190-1644214581 ECI TECHNOLOGY CONTROL BOARD, RCI-F 94V0 3500, PCB TLA51016062 APPLIED CERAMICS RING OUTER, 1.50", SSGD, R2 CHAMBER 91-00745A16746 APPLIED MATERIALS CABLE ASSY,MOD PWR DRIVER CONTROL I/O TO 0150-0103013455 APPLIED MATERIALS WASCO SW,VCR-4,CLOSE DECREASING TOR,75 TORR 0190-0913317422 APPLIED MATERIALS BOX DB9 TRI-PORT CHX PASS-THRU  0010-3712817762 APPLIED MATERIALS WELDMENT ELBOW 5RA N2 LOADLOCK PURGE 0050-2692310058 APPLIED MATERIALS VLV MNL DIAPH 3500PSI,VERIFLO 944MSFSFF  3870-0130713704 APPLIED MATERIALS SPANNER WRENCH, 300MM ENDURA 0270-007272463 TELTEC PCB, INPUT BOARD,TEMPERATURE CONTROLLER, 965157D 96515816733 APPLIED MATERIALS PRESS. TRANSD. HRN 1-6 0140-09996