输入/输出接口是PLC与现场I/O设备或其它外部设备之间的连接部件。PLC通过输入接口把外部设备(如开关、按钮、传感器)的状态或信息读入CPU,通过用户程序的运算与操作,把结果通过输出接口传递给执行机构(如电磁阀、继电器、接触器等)。 在输入/输出接口电路中,一般均配有电子变换、光耦合器和阻容滤波等电路,以实现外部现场的各种信号与系统内部统一信号的匹配和信号的正确传递,PLC正是通过了这种接口实现了信号电平的转换。发光二极管(LED)用来显示某一路输入端子是否有信号输入。当系统的I/O点数不够时,可通过PLC的I/O扩展接口对系统进行扩展。 1747-M3 EEPROM MEMORY,4K 1747-M4 EEPROM MEMORY,4K 1747-M5 ADAPTER SOCKET-PKG. 5 1747-NP1 WALL MOUNT PWR SUPPLY 120V AC INPUT 1747-NP2 GLOBAL DESK TOP PWR SUPPLY 85/285 V AC IN 1747-OCAPINT WINDOWS NT API FOR 1771-OC MODULE 1747-OCDPDE OC DOC SET/GERMAN 1747-OCDPES OC DOC SET/SPANISH 1747-OCDPFR OC DOC SET/FRENCH 1747-OCDPIT OC DOC SET/ITATIAN 1747-OCDR16 16 MB DRAM FOR 1747 OPEN CONTROLLER 1747-OCDR32 32 MB DRAM FOR 1747 OPEN CONTROLLER 1747-OCDR4 4 MB DRAM TO 1747 OPEN CONTROLLER 1747-OCENET ETHERNET(10/100 BASET)MODULE 1747-OCF 266 MHZ OPEN CONTROL PROCESSOR 1747-OCFAN1 FAN ASSEMBLY FOR 1747 OPEN CONTROLLER 1747-OCIDE1 ATA CARRIER CARD/IDE DRIVE EXPANDER MODULE 1747-OCIDE25 2.5 IDE DRIVE EXPANSION MODULE 1747-OCKTX SINGLE CHANNEL 1-B COMM OPTION MODULE 1747-OCKTXD DUAL CHANNEL A-B COMM OPTION MODULE 1747-OCP252 PARALLEL ADAPTER CABLE 1747-OCPCI2 2-SLOT PCI BUS FOR 1747 OPEN CONTROLLER 1747-OCPCI3 3-SLOT PCI BUS FOR 1747 OPEN CONTROLLER 1747-OCPCI4 4-SLOT PCI BUS FOR 1747 OPEN CONTROLLER 1747-OCPCI5 5-SLOT PCI BUS FOR 1747 OPEN CONTROLLER 1747-OCPCI6 6-SLOT PCI BUS FOR 1747 OPEN CONTROLLER 1747-OCPCM1 PCMCIA OPTION MODULE 1747-OCPCM2 PCMCIA OPTION MODULE WITH CARD & SOCKET 1747-OCS92 SERIAL ADAPTER CABLE 1747-OCSBC SERIAL BOOT CABLE 1747-OCSDCK FLASHDRIVE CABLE KIT FOR 1747 OPEN CONTROLLER 1747-OCTS OPEN CONTROLLER FAMILY SUPPORT CONTRACT 1747-OCUS OPEN CONTROLLER FAMILY UPDATE SERVICE 1747-OCVGA1 VGA OPTION MODULE FOR 1747 OPEN CONTROLLER PCI BUS 1747-OCVGAE COMBO OPTION MODULE 1747-PCIAA 1747 PCI BUS INTERFACE KIT 1747-PCIAB 1747 PCI BUS INTERFACE KIT 1747-PCIBA 1747 PCI BUS INTERFACE KIT 1747-PCIBB 1747 PCI BUS INTERFACE KIT