(二)输入输出模块的选择
输入输出模块的选择应考虑与应用要求的统一。例如对输入模块，应考虑信号电平、信号传输距离、信号隔离、信号供电方式等应用要求。对输出模块，应考虑选用的输出模块类型，通常继电器输出模块具有价格低、使用电压范围广、寿命短、响应时间较长等特点；可控硅输出模块适用于开关频繁，电感低功率因数负荷场合，但价格较贵，过载能力较差。输出模块还有直流输出、交流输出和模拟量输出等，与应用要求应一致。
可根据应用要求，合理选用智能型输入输出模块，以便提高控制水平和降低应用成本。
考虑是否需要扩展机架或远程I/O机架等。
(三)电源的选择
PLC的供电电源，除了引进设备时同时引进PLC应根据产品说明书要求设计和选用外，一般PLC的供电电源应设计选用220VAC电源，与国内电网电压一致。重要的应用场合，应采用不间断电源或稳压电源供电。
如果PLC本身带有可使用电源时，应核对提供的电流是否满足应用要求，否则应设计外接供电电源。为防止外部高压电源因误操作而引入PLC，对输入和输出信号的隔离是必要的，有时也可采用简单的二极管或熔丝管隔离。
(四)存储器的选择
由于计算机集成芯片技术的发展，存储器的价格已下降，因此，为应用项目的正常投运，一般要求PLC的存储器容量，按256个I/O点至少选8K存储器选择。需要复杂控制功能时，应选择容量更大，档次更高的存储器。
(五)冗余功能的选择
1．控制单元的冗余
(1)重要的过程单元：（包括存储器）及电源均应1B1冗余。
(2)在需要时也可选用PLC硬件与热备软件构成的热备冗余系统、2重化或3重化冗余容错系统等。
2．I/O接口单元的冗余
(1)控制回路的多点I/O卡应冗余配置。
(2)重要检测点的多点I/O卡可冗余配置。3）根据需要对重要的I/O信号，可选用2重化或3重化的I/O接口单元。
(六)经济的考虑
PanelView 1000 Operator Interface
Allen Bradley 2711-T5A16L1 Allen Bradley PanelView 550 Operator Interface
Allen Bradley 2711-T5A2L1 Allen Bradley PanelView 600 Operator Interface
Allen Bradley 2711-T5A5L1 Allen Bradley PAC Wright 70 Operator Interface
Allen Bradley 2711-T5A8L1 Allen Bradley PanelView 550 Touchcreen Display
Allen Bradley 2711-T6C10L1 Allen Bradley Panel View 600 Operator Interface
Allen Bradley 2711-T6C15L1 Allen Bradley PanelView 600 Operator Interface
Allen Bradley 2711-T6C16L1 Allen Bradley PanelView 600 Operator Interface
Allen Bradley 2711-T6C1L1 Allen Bradley PanelView 600 Touchcreen Display
Allen Bradley 2711-T6C20L1 Allen Bradley PanelView 600 Operator Interface
Allen Bradley 2711-T6C2L1 Allen Bradley PanelView 600 Operator Interface
Allen Bradley 2711-T6C3L1 Allen Bradley Panelview 600 Operator Interface
Allen Bradley 2711-T6C5L1 Allen Bradley PanelView 600 Operator Interface
Allen Bradley 2711-T6C8L1 Allen Bradley PanelView 600 Operator Interface
Allen Bradley 2711-T9A1 Allen Bradley PanelView 900 Operator Interface
Allen Bradley 2711-T9A2 Allen Bradley PanelView 900 Operator Interface
Allen Bradley 2711-T9A3 Allen Bradley PanelView 900 Operator Interface
Allen Bradley 2711-T9A5 Allen Bradley PanelView 900 Operator Interface
Allen Bradley 2711-T9C1 Allen Bradley PanelView 900 Operator Interface
Allen Bradley 2711-T9C3 Allen Bradley PanelView 900 Operator Interface
Allen Bradley 2711-TC1 Allen Bradley PanelView 1200 Operator Interface
Allen Bradley 2711-TC1X Allen Bradley PanelView Operator Interface
Allen Bradley 2711E-K10C6 Allen Bradley Panel View 1000e Operator Interface
Allen Bradley 2711E-K14C15 Allen Bradley PanelView 1400e Operator Interface
Allen Bradley 2711E-K14C6 Allen Bradley PanelView 1400E Operator Interface
Allen Bradley 2711E-T10C6 Allen Bradley PanelView 1000e Operator Interface
Allen Bradley 2711E-T1406 Allen Bradley Panelview 1400e Operator Interface
Allen Bradley 2711E-T14C6 Allen Bradley PanelView 1400E Operator Interface
Allen Bradley 2711P-PR Allen Bradley PanelView Plus 700 Operator Interfac
Allen Bradley 2711P-RP Allen Bradley PanelView Plus 1250 Operator Interfa
Allen Bradley 2711P-RP1 Allen Bradley Panelview Logic Module
Allen Bradley 2711P-T10C4D1 Allen Bradley PanelView Plus 1000 Operator Interface
Allen Bradley 2711P-T12C4D2 Allen Bradley PanelView Plus 1250 Operator Interface
Allen Bradley 2711P-T7C4D1 Allen Bradley PanelView Plus 700 Operator Interfac
Allen Bradley 2755-SN5 Allen Bradley AdaptaScan Controller
Allen Bradley 2760-RB Allen Bradley Flexible Interface Module
Allen Bradley 2771-T9A5 Allen Bradley PanelView 900 Operator Interface
Allen Bradley 4084B Interface PCB.
Allen Bradley 4088-490-01-S1FX Allen Bradley Dialog Plus
Allen Bradley 4100-232-R IMC S Class 2 Axis motion controller
Allen Bradley 4100-234 Allen Bradley IMC S Class Axis motion controller
Allen Bradley 4100-234-R IMC S Class Axis motion controller
Allen Bradley 4100-234-RL IMC S Class 4 Axis motion controller
Allen Bradley 5005 Main CPU
Allen Bradley 5120-P1A Allen Bradley Pyramid Power Supply
Allen Bradley 5130-KA A DH/DH+ Interface Module
Allen Bradley 5130-MRM2 A Pyramid 384KResource Manger
Allen Bradley 5130-RM 2 A Resource Manager Host Module
Allen Bradley 5130-RM A / 5130-MRM1 A Resource Manager Host/128k Daughterboard
Allen Bradley 5130-RM A / 5130-MRM2 A Resource Manager Host/384k Daughterboard
Allen Bradley 5130-RM A / 5130-MRMS A Resource Manager Host/128K Daughterboard
Allen Bradley 5130-RM2A 384K Resource Manager
Allen Bradley 5150-RS A Remote I/O Scanner Host Board
Allen Bradley 5150-RS A / 5150-MRS A Remote I/O Host / Daughter Booard
Allen Bradley 5150-RS5 A Remote/local I/O Scanner
Allen Bradley 5250-LP B / 5250-MLP1 B Logic Processor/256K Daughter Board
Allen Bradley 5250-LP B / 5250-MLP2 B Logic Processor/512K Daughter Board
Allen Bradley 5250-LP B / 5250-MLP4 B Logic Processor/2meg Daughterboard
