与微型计算机一样，除了硬件以外，还必须有软件。才能构成一台完整的PLC。PLC的软件分为两部分:系统软件和应用软件。存放系统软件的存储器称为系统程序存储器。

 PLC存储空间的分配：虽然大、中、小型PLC的CPU的***大可寻址存储空间各不相同，但是根据PLC的工作原理，其存储空间一般包括以下三个区域：系统程序存储区，系统RAM存储区（包括I/O映象区和系统软设备等）和用户程序存储区。

NetApp FAS3020 Filer DS14MK2 14 x 300GB X276A-R5 4.2TB 

NetApp FAS270c Network Appliance Filer w/ 2TB 14 x X274

NetApp FAS3050C Network Appliance Filer Head

NetApp FAS3020c 2x Filers / 2x DS14 MK2 / 28x 146GB

NetApp DS14 MK2 Shelf w/ (14) 144GB 10K HDD

Netapp FAS2050C Cluster Filer Head Dual Controller 

Netapp FAS2050C Cluster 2x Controller FAS2050 Clustered

NetApp SK-FAS960 Spares Kit for FAS960 System

NetApp X749A DC Power Supply Network Appliance

NetApp X3772B F820/F810/C3100 Motherboard

NetApp SK-F840B Spares Kit for F840 Filer

NETAPP FAS3050c Cluster 2 Filer Heads FAS 3050 Disk

NETAPP FAS3050C Clustered Filer Heads FAS 3050 Cluster 

Network Appliance FAS3050C Cluster 2 Filer Heads Netapp

NETAPP FAS3050c Cluster 2 Filer Heads FAS 3050 @@@@@@@@

NETAPP FAS3050c Cluster 2 Filer Heads FAS3050 Clustered

NETAPP FAS3050c Cluster 2 Filer Head FAS3050 1 yr wrty

NETAPP FAS3050C Cluster 2 Filer Heads FAS3050 @@@@