Storage is one of the most important concerns in industrial computers and control systems. In such context data storage systems and devices not only store but also manage and protect the information. Hard disk drives, tape drives, optical storage devices, and removable cartridge drives are the most common examples. Other options include FLASH technology such as disk on chips, disk on module, or memory sticks. Data storage systems contain all or some of such devices depending upon the requirements.

Data Storage Options for Industrial Computers

Hard Disk Drives

Hard disk drives are kept inside computer case. Integrated drive electronics (IDE) and small computer system interface (SCSI) are the interfaces for hard disks.

Tape Drives

Tape drives allow storing data from computers to tape cartridges. Tape drives are available as internal as well as external. External tape drives can be connected to more than one computer. Internal tape drives are less expensive than those of external.

Floppy Disk Drives

Floppy drives allow storing data on 3.5-inch floppy disks. Floppy disks can store only 1.32 MB to 3.5 MB of data.

Removable Cartridges

Removable cartridges are covered with metal or plastic. They are faster than floppy disks but slower than hard disks. They can be inserted or removed similar to floppy disks.

Compact Disk Drives

Compact disk drives are the optical storage devices. Such devices allow storing data on a compact disk. There are three types of compact disk drives. These include CD-ROM (compact disk read only memory) drives, CD-R (compact disk re record able) drives, and CD-RW (compact disk re write able) drives. CD-ROM drives can only read but cannot store data from computer to CDs. CD-R drives can copy data from computer to CD only once but read many times. CD-RW drives can read, write, erase, and re-write on the compact disks (CDs) several times. A compact disk can store 700 MB – 750MB of data.

Digital Versatile Disk (DVD) Drives

DVD drives not only read or record the digital versatile disks (DVDs) but also support the compact disk. One DVD can store 4.7 GB to 17 GB of data. Access rate of DVD drives are between 600 kilobits per second (Kbps) and 1.3 mega bits per second (Mbps).

Data Storage Physical Specifications

Physically data storage systems are specified by their capacity, data transfer rates, mounting styles, and form factors.

Form Factor

Form factor depends upon the length, height, width, and capacity of the data storage systems. These are expressed in centimeters (cm), millimeters (mm), or inches (in). Capacity refers to the maximum data that a storage device can store. It is expressed in byes such as GB (gigabytes), or MB (megabytes).

Data Transfer Rate

Data transfer rate refers to internal and external data transfer rates. Internal data transfer rate is data transfer speed between controller and disks. External data transfer rate is the data transfer speed between controller and central processing unit (CPU).

Mounting Style

Data storage systems are available in a variety of mounting styles. These include rack mount, panel mount, or free standing. Storage systems that can be attached to chassis or panel are also available. To mount the drives integrally they are normally soldered or hard wired in place.