Problem
A specialized network-based hardware device designed to perform a single or specialized set of functions with client access independent of any operating system or proprietary protocol," according to Wikipedia.
Device servers provide independence from proprietary protocols as well as the ability to perform a variety of functions. The RAID controller application mentioned above is just one of many where device servers can be used to connect any device or "machine" to the network.
With some success, PCs have been used to network serial devices. This, however, necessitated the serial port product having software that could run on the PC, and then having that application software allow the PC's networking software to access the application. This task mirrored the issues with putting Ethernet on the serial device, so it was not a satisfactory solution. A device server must provide a simple solution for networking a device and allow access to that device as if it were locally available via its serial port in order to be successful. Furthermore, the device server should support the wide range of connection options that a device may require on both the serial and network sides of a connection. Should the device always be connected to a specific host or PC? Is it possible that multiple hosts or network devices will want or need to connect to the newly networked serial device? Are there any specific requirements for an application that requires the serial device to reject a network connection under certain conditions? The bottom line is that a server must be able to service a wide range of application requirements while also meeting all of the demands of those applications.
Discuss how device servers are used to improve the usability of various applications such as:
Data Collection, Factory/Industrial Automation, Security Systems, Bar Code Readers and Point-of-Sale Scanners, Medical Applications, M2M Wireless Communication/Networking.