Device Bay

One of our objectives in this column has been to cover trends and developments in computer technology that have a high probability of impacting manufacturing. Two such developments covered recently were Firewire and Universal Serial Bus (USB). This month takes a look at a development called Device Bay, a new technology that enhances the use of both FireWire and USB.

Device Bay is an industry specification defining a mechanism that makes upgrading peripheral devices on PCs as easy as inserting a floppy disk into a drive. Thus it eliminates the need to turn the power off, open up the PC chassis, unscrew cards, and restart the system. Device Bay is an open specification developed by Microsoft, Intel, and Compaq working jointly with the computer industry. It is applicable to devices such as CD drives, DVD drives, smart card readers, satellite television decoders, high-speed digital modems, network cards, hard drives, high-capacity removable media drives, audio devices, and so on. Device Bay applies to all classes of computers including desktop, laptops, home and server computers, which means that it will also be applicable to PC-based machine controls.

The Device Bay specification defines the interface characteristics for both peripheral devices and the system bays in the computer. It works with both IEEE 1394 (FireWire) and USB and enhances them by providing a mechanism for insertion and removal notification. A Device Bay-enabled operating system uses a software controlled interlock to make sure all applicable open files and applications are closed before the user is allowed to remove a device such as a hard drive. Notification is a necessary feature for assuring the integrity of user data, applications, and operating systems, when hot insertion and removal of devices are performed.

The "bay" in Device Bay is defined as a receiving slot, dock, or cavity in a computer that provides connectivity for a device. The connector set consists of a plug connector that resides on the removable device and a receptacle connector that resides in the bay. There are three size bays: DB32 (32 mm), DB20 (20 mm), and DB13 (13 mm). The largest, DB32, is for desktop computers. DB20 is designed for laptops and desktops. DB13 is designed for laptops but can also be used on desktops. DB13 and DB20 devices are designed to operate on less power than DB33 and are therefore more appropriate for laptop computers. The Device Bay standard has been designed so there is a great deal of interchangeability between the three sizes. A DB20 and DB13 device can be used in a DB32 bay with one adapter. Additionally, a DB20 bay will accept a DB20 and DB13 device without any additional adapters. A DB13 will only accept DB13 devices.

The major benefit of Device Bay is that it allows the user to easily upgrade, replace, or add devices without opening the PC case. Peripherals that are inserted into a Device Bay are automatically configured so the user can start using a newly inserted device immediately. This is accomplished by a plug and play capability operating system running in the computer. Also, devices can be inserted into or removed from computers while they are powered up. This eliminates the time-consuming power-down and rebooting cycle, often a very time consuming event in a CNC machine.

Although initially developed for the consumer, corporate users have found value in Device Bay as well. In the office environment Device Bay allows a computer with a failed hard drive to be functional in minutes instead of hours. Also, systems that previously required a CD-ROM drive for software installation now would only require an empty Device Bay slot. When the drive is needed, it can be quickly inserted, used, and removed again without rebooting the system. The reduced cost for service and upgrading PCs could significantly decrease the total cost of ownership for both PCs and machine controls.

How soon will we see Device Bay on PC-based machine controls? Compaq Computer Corp. is expected to release desktop computers late this year with Device Bay followed by laptops next year. So far the other computer manufactures have been slow to commit to this open standard. We can expect PC-based controls to follow suit one to two years after it becomes widely available on a broad base of PCs. This is a device connection technology to watch.