PLC新发展状态及趋势
现代PLC的发展有两个主要趋势：其一是向体积更小、速度更快、功能更强和价格更低的微小型方面发展；其二是向大型网络化、高可靠性、好的兼容性和多功能方面发展。
（1）大型网络化主要是朝DCS方向发展，使其具有DCS系统的一些功能。网络化和通信能力强是PLC发展的一个重要方面，向下可将多个PLC、I/O框架相连；向上与工业计算机、以太网、MAP网等相连构成整个工厂的自动化控制系统。
（2）多功能随着自调整、步进电机控制、位置控制、伺服控制等模块的出现，使PLC控制领域更加宽广。
如西门子公司早在80年代就研制出了多回路闭环控制模块、步进电机控制模块、仿真模块和通信处理模块等。在1995年西门子又成功地开发出了S7200、S7300系列，它具有TD 200和COROS OPS操作模板(OPS)为用户提供了方便人机界面，用户程序三级口令保护，极强的计算性能，完善的指令集，MPI接口和通过工业现场总线PROFIBUS以及以太网联网的网络能力，强劲的内部集成功能，全面的故障诊断功能；模块式结构可用于各处性能的扩展，脉冲输出晶闸管步进电机和直流电机；快速的指令处理大大缩短了循环周期，并采用了高速计数器，高速中断处理可以分别响应过程事件，大幅度降低了成本。
（3）高可靠性由于控制系统的可靠性日益受到人们的重视，一些公司已将自诊断技术、冗余技术、容错技术广泛应用到现有产品中，推出了高可靠性的冗余系统，并采用热备用或并行工作、多数表决的工作方式。S7400 PLC即使在恶劣、不稳定的工作环境下，坚固、全密封的模板依然可正常工作，在操作运行过程中模板还可热插拔。
可编程控制器（programmable logical controller，简称PLC）已经越来越多地应用于工业控制系统中，并且在自动控制系统中起着重要的作用。所以，对PLC的正确选择是重要的。
面对众多生产厂家的各种类型PLC，它们各有优缺点，能够满足用户的各种需求，但在形态、组成、功能、网络、编程等方面各不相容，没有一个统一的标准，无法进行横向比较。下面提出在自动控制系统设计中对PLC选型的一些看法，可以在挑选PLC时作为参考。
Yaskawa / Magnetek CIMR-G5M4022 40HP 460V AC Drive
One-day shipping available
CACR-HR30BB Yaskawa Yasnac AC Servo Drive ServoPack
One-day shipping available
CACR-HR30BBY22 Yaskawa Yasnac AC Servo Drive ServoPack
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CACR-HR30UBY9 Yaskawa Yasnac AC Servo Drive ServoPack
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Yaskawa / Magnetek CIMR-G5M4015 25HP 460V AC Drive
One-day shipping available
CACR-SR20BB1AM Yaskawa Yasnac AC Servo Drive ServoPack
One-day shipping available
CACR-SR20BB1AF Yaskawa Yasnac AC Servo Drive ServoPack
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CACR-SR20BB1BF Yaskawa Yasnac AC Servo Drive ServoPack
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CACR-SR20SB1AFY118 Yaskawa Yasnac AC Servo Drive ServoP
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CACR-SR20SB1BFY118 Yaskawa Yasnac AC Servo Drive ServoP
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CACR-SR20BZ1SFY259 Yaskawa Yasnac AC Servo Drive ServoP
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CACR-SR20SB1BF Yaskawa Yasnac AC Servo Drive ServoPack
One-day shipping available
CACR-SR20SB1BFY100 Yaskawa Yasnac AC Servo Drive ServoP
One-day shipping available
CACR-SR20BE12G-E Yaskawa Yasnac AC Servo Drive ServoPac
One-day shipping available
CACR-SR20BY1SFY17 Yaskawa Yasnac AC Servo Drive ServoPa
One-day shipping available
CACR-SR20SZ1SFY91 Yaskawa Yasnac AC Servo Drive ServoPa
One-day shipping available
CACR-SR20SB1AFY100 Yaskawa Yasnac AC Servo Drive ServoP
One-day shipping available
CACR-SR20BB1BF-H Yaskawa Yasnac AC Servo Drive ServoPac
One-day shipping available
CACR-SR20TZ6SM-E Yaskawa Yasnac AC Servo Drive ServoPac
One-day shipping available
SGDB-44ADS Yaskawa AC ServoPack SIGMA I Servo Drive
One-day shipping available
CACR-HR20BB Yaskawa Yasnac AC Servo Drive ServoPack
One-day shipping available
YASKAWA CIMR-F7U2011 DRIVE 240V 45A ***NIB***
Yaskawa / Magnetek AC Drive CIMR-G3U2011 15HP 230V, NEW
One-day shipping available
SGDB-30ADGY8 Yaskawa AC ServoPack SIGMA I Servo Drive
One-day shipping available
CACR-SR15BE12G-E Yaskawa Yasnac AC Servo Drive ServoPac
One-day shipping available
CACR-SR15BB1AF Yaskawa Yasnac AC Servo Drive ServoPack
One-day shipping available
CACR-SR15SZ1SDY77 Yaskawa Yasnac AC Servo Drive ServoPa
One-day shipping available
CACR-SR15SB1AF Yaskawa Yasnac AC Servo Drive ServoPack
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CACR-SR15SZ1SDY214 Yaskawa Yasnac AC Servo Drive ServoP
One-day shipping available
CACR-SR15BB1BFY288 Yaskawa Yasnac AC Servo Drive ServoP
One-day shipping available
CACR-SR15BB1AMY114 Yaskawa Yasnac AC Servo Drive ServoP
One-day shipping available
CACR-SR15BB1ESY114 Yaskawa Yasnac AC Servo Drive ServoP
One-day shipping available
CACR-SR12TZ6SM-E Yaskawa Yasnac AC Servo Drive ServoPac
One-day shipping available
CACR-SR15BB1BF Yaskawa Yasnac AC Servo Drive ServoPack
One-day shipping available
CACR-SR15SB1AFY100 Yaskawa Yasnac AC Servo Drive ServoP
One-day shipping available
CACR-SR15BE17SY107 Yaskawa Yasnac AC Servo Drive ServoP
One-day shipping available
CACR-SR15SB1BFY100 Yaskawa Yasnac AC Servo Drive ServoP
One-day shipping available
CACR-SR15BE12G Yaskawa Yasnac AC Servo Drive ServoPack
One-day shipping available
CACR-SR15SZ1SSY228 Yaskawa Yasnac AC Servo Drive ServoP
One-day shipping available
CACR-SR15BE13SY44 Yaskawa Yasnac AC Servo Drive ServoPa
One-day shipping available
Yaskawa / Magnetek CIMR-G3U4015 20HP 460V AC Drive G3
One-day shipping available
SGDB-44ADG Yaskawa AC ServoPack SIGMA I Servo Drive
One-day shipping available
Yaskawa CACR-SV3 AAA Servo Drive Yasnak Motoman
CIMR F7U20P7 Yaskawa SERIES Varispeed Drive 1HP, 230V
Yaskawa ServoPack Servo Drive CACR-HR20BB
YASKAWA YASNAC CIMR MT III 7.5K SPINDLE DRIVE
YASKAWA CIMR-MTIII-7.5K SPINDLE DRIVE NIB FREE SHIP
Yaskawa Varispeed 505 MT Spindle Drive CDMR-MR-11K MORI
Yaskawa CACR-SR15BE12G Servo Drive
YASKAWA VARISPEED 505 SPINDLE DRIVE CDMR-ZII JPDC-C036
YASKAWA INVERTER MOTOR SPEED CONTROLLER FREQUENCY DRIVE
YASKAWA SGDB-60ADSY44 SERVOPACK SERVO DRIVE 8HP 40A*NIB
