Ben's Bits

This is something I wrote last week for a client, perhaps someone else will find it useful as well… -Ben

Technology Brief: Scanning over Networks
Date: March 18, 2005
by Ben Franske

Executive Summary:
Four main technologies may be used for sharing a scanner over a network, each with unique pros and cons. Because scanners have been traditionally deployed as standalone devices most if not all solutions for using them in a networked environment are less than optimal. Further complicating the matter is the fact that many of the inexpensive new scanners do not use, or use a heavily modified, TWAIN driver interface that has been the standard for a number of years. Mixing PCs and Macintoshes can also add a twist to this problem.

The scanner sharing technologies explored in this document:

• Shared Scanning Workstations
• USB Servers
• Sharing Software
• Network Enabled Scanners

Traditionally scanners have been designed as standalone devices and a solution commonly used is to setup a “scanning station” complete with PC where employees can scan in documents and save them to a network share, return to their desk and further manipulate the image as needed. Obviously this is the least expensive solution and the most straightforward which explains its popularity. On the downside, you need to dedicate space for both the PC and scanner. There is also the issue of how logins to the scanning workstation should be done (shared login, domain logins, etc). This method also requires the intermediate step of saving the document as an image before manipulating it, rather than using TWAIN to directly import it into your application.

The second major technology for sharing scanners is the use of a USB server device. In a situation such as this the USB scanner is connected to an external USB server device such as the Digi International AnywhereUSB or the Keyspan USB Server, clients can connect one at a time to the scanner and must disconnect before the scanner is available for another person to use. In general the Digi International product is considered a more mature commercial product and the Keyspan a newer consumer/SOHO device. The major benefit to this model is the fact a PC is not required at the scanner location. The downside is that only one person can connect to the scanner at a time and if someone forgets to disconnect it is unavailable to everyone else and the scanner must be USB as opposed to SCSI. Because this method essentially adds new USB ports to the computer (simply extending them over Ethernet) each PC is required to have the scanner drivers installed, but the scan can be imported directly into the application as if the scanner was local.

Thirdly, some software exists that allows you to share scanners over a network. Specifically, Umax includes it with some of their scanners though that is pretty rudimentary software. Third party software such as RemoteScan will also work with any TWAIN scanner. With a setup such as this the scanner remains tied to a scan server computer that could be either a dedicated PC or the most frequent users PC. This is much less expensive than a dedicated network scanner, but is fairly new technology and relatively untested. It remains to be seen how the interfacing between the scanner driver, the scanner, and the client computer is done. It should be noted that Macintosh OS X does support native scanner sharing through the “Image Catpure” application preferences and the Rendevouz technology though this only works sharing between Macintoshes.

Finally, some manufacturers make network enabled scanners which are designed for built in scan servers similar to print servers commonly found on business class printers. HP has discontinued their network scanners (eg. Scanjet 4si/5) in favor of “document sending” machines which are more like fax machines with Ethernet jacks, not photo quality, Xerox has made a similar move. As far as I can tell Afga, Kodak and Umax the other major players in the photo-scanning arena do not manufacture networked scanners. HP, Lexmark and Brother all make multifunction devices that can be networked and include the ability to scan, but again this is not usually a very high-resolution scanner. One manufacturer with a viable high-resolution network scanner is Epson. The Epson GT series of scanners is specifically designed for group environments. The GT-30000 includes a built in scan server while the GT-15000 requires an optional network interface card. In addition to the GT series the Epson Expression 10000XL scanners can also use the optional network interface card.

Conclusions:
Obviously the best solution from a technology standpoint is a scanner designed for use in a networked environment such as the Epson GT-30000. Of course, the greatest downside to a solution such as this is the sheer cost of a true network scanner. As of this writing the GT-30000 is roughly $4000, the GT-15000 plus the network card coming in at just under half of that and the 10000XL somewhere in the middle. The next best solution would likely be the RemoteScan software followed by the USB server or a dedicated workstation.

Online Resources:
Remote-Scan Software
Sharing an Imaging Device in OS X
Sharing a UMAX Scanner Over a Network
Epson Scanners
Keyspan USB Server
Digi International AnywhereUSB