输入输出设备：它用以接收信号或输出信号，便于与PLC进行人机对话。输入的有条码读入器，输入模拟量等。输出的有打印机、编程器、监控器虽也可对PLC输入信息，从PLC输出信息，但输入输出设备实现人机对话更方便，可在现场条件下实现，并便于使用。随着技术进步，这种设备将更加丰富。
ENCODER ROD 426 E 500
FANUC CONTROL BOARD A16BC
INDRAMAT SERVO CONTROLLER KDS 1.W1
INDRAMAT SERVO MOTOR MDD112B-N-030-N2M-130PB2
GROUPE SCHNEIDER DRIVE ATV-66D64-N4 REPAIR SERVICE
SIEMENS SERVO MOTOR 1FK7080-5AF71-1EB3
ALLEN BRADLEY DRIVE 1336F-BRF75-AA-EN-GMS5
ALLEN BRADLEY DRIVE 1336-B040-EAG-S1
ALLEN BRADLEY SERVO MOTOR 1326AB-B3E-21
ALLEN BRADLEY PHOTOSWITCH 42MRU-5200 SER.B
FANUC PULSECODER UNIT AT001
SIEMENS SERVO MOTOR 1FT6034-1AK71-4AH1
MAGNETEK SERVO DRIVE A
ALLEN BRADLEY PANELVIEW 600 2711-T6C5L1
INDRAMAT HARD DRIVE BGR BTV20/30-FESTPLATTE
CUTLER HAMMER PANELMATE 7685T-12
SIEMENS CONTROLLER CARD 6SN1118-0NH11-0AA0
SIEMENS SERVO MOTOR 1FK7103-5AF71-1EH2
FANUC BRAKE CONTROL MODULE A03B-0801-C056
SCHNEIDER INVERTER ATV71HU75N4
INDRAMAT 3 PHASE PERMANENT MOTOR MKE098B-047-KP1-BUNN
CINCINNATI MILACRON SERVOMOTOR
SIEMENS SERVO MOTOR 1FK7101-5AF71-1AG0
SIEMENS SINUMERIK EPROM BOARD
ALLEN BRADLEY PANELVIEW 2711-K10C1
PARKER COMPAX 3 S038V4F11I12T11M12
YASKAWA DRIVE JZNC-XIU01B
LENZE SERVOMOTOR MDSKABS112-22
ALLEN BRADLEY 1775-MEA
MITSUBISHI AC SERVO MOTOR HA-SE52
FANUC BOARD A16BB
SIEMENS SERVO MOTOR 1FK7103-5AF71-1AB5
KAWASAKI SERVO DRIVE
NEW LISTING HELLER CNC CONTROL PLT90(80)
SIEMENS SERVO MOTOR 1FK7100-5AF71-1GH0
BALDOR SERVO DRIVE TDSU
FANUC AC SERVO MOTOR A06B-0571-B275