描述
PLC的存储器分为系统程序存储器和用户程序存储器。系统程序相当于个人计算机的操作系统，它使PLC具有基本的智能，能够完成PLC设计者规定的各种工作。系统程序由PLC生产厂家设计并固化在ROM内，用户不能直接读取。PLC的用户程序由用户设计，它决定了PLC的输入信号与输出信号之间的具体关系。用户程序存储器的容量一般以字(每个字由16位二进制数组成)为单位，三菱的FX系列PLC将用户程序存储器的单位称为步(Step，即字)。小型PLC的用户程序存储器容量在lK字左右，大型PLC的用户程序存储器容量可达数M(兆)字。
NetApp Disk Drive,500GB,7200 RPM,SATA,A,-C,R5
One-day shipping available
NetApp Disk Drive,500GB,7200 RPM,SATA,A,R5 X267A-R5
One-day shipping available
NetApp X267A-R5-C 500GB 7200 RPM SATA A,-C,R
One-day shipping available
NetApp Disk Drive,500GB,7200 RPM,SATA,A,-C,R5 X267A-R5
One-day shipping available
Netapp Disk Drive,500GB,7200 RPM,SATA,A,R5 SATA X267
One-day shipping available
NetApp X217B 4GB 7200 SCSI Disk for SS1
NetApp SP-611A Power Supply for FC9
NetApp X267_HKURO500SSX SP-267A-R5 500GB SATA Disk
One-day shipping available
NetApp X267A-R5 500GB SATA Disk Drive for DS14MK2AT
One-day shipping available
NetApp X267A-R5-C 500GB 7200 RPM SATA A,-C,R SATA
