采用模块化结构为了适应各种工业控制需要，除了单元式的小型 PLC 以外，绝大多数 PLC 均采用模块化结构。PLC 的各个部件，包括 CPU，电源，I/O 等均采用模块化设计，由机架及电缆将各模块连接起来，系统的规模和功能可根据用户的需要自行组合。
USON 74249 Power Supply Module
Foxboro 75TUA-PTEA Totalizer 75 Series 75TUAPTEA
Research-Cottrell 307897-B CPU RK-2064 Microprocessor
Lutron HP-2 Omega II Single Circuit High Power Dimming
Thermadyne 19X2416 Control Board 2416
Easson ES-8 Digital Readout Control Panel ES8
Mitsubishi Electric F-20ES-UA1 Melsec SSR Unit F-20E
RELIANCE ELECTRIC 0-52824 CURRENT LOOP REG CLRA 052824
Siemens 7RW6000-2EA00-0DA0/BB 7RW60002EA000DA0/BB
Allen Bradley 1747-L531 CPU Module SLC500
Toshiba VFS9-4007PL-WN Inverter Drive VFS94007PLWN
Blue Ridge Technologies RP32 Relay Panel Lighting Contr
SIEMENS FURNAS 91KJ34A0A INDUCTION MOTOR CONTROLLER
RELIANCE ELECTRIC 14C229 Master Isolated Ref Receiver
Sanyo Denki San Driver PDT-093-29 Amplifier PDT09329
Allen Bradley 1336-SN-SP16A PCB Inverter 1336SNSP16A
DT Research Display DT550 Integrated Digital Terminal
Hitachi 280594 RRZK1315-P-PCB A0167
