Installing the printers
Installing the printers for a printer pool is a straightforward procedure. You should begin by physically connecting just one of the printers to the system acting as the print server and installing its drivers. If you'll be using printers that are connected to both USB and parallel ports, I recommend that you start with one of the printers that will connect via the USB port. That's because the installation procedure will be much faster, since chances are good that the printer is a Plug and Play device and Windows XP will begin installing the printer as soon as you plug in the cable.
As soon as you've connected the first printer and installed the drivers, you should test the printer to make sure it's working correctly. Once you confirm that you can indeed print to the printer, you should rename the printer with a name that reflects the fact that it is a printer pool. For example, if it's a Lexmark printer, you might name it Lexmark Printer Pool. Now, share the printer on the network using the new name as the share name. Then, make sure that you can print to the printer from a remote system.
At this point, you can connect the other printers to the system acting as the print server. As you do so, you can use the existing printer drivers. Keep in mind that the additional printers will remain local printers. In other words, don't share them over the network.
When connecting multiple USB printers to a print server via USB ports, you really should connect them in the order of the USB port numbers. In other words, connect the first USB printer to the first USB port on the computer or on the hub, and so on.
Considering the plug-and-play nature of USB, it really shouldn't matter which USB port you use. However, I've discovered that when it comes to installing multiple USB printers on the same system for use with a printer pool, this seemingly unnecessary bit of meticulous attention to detail is indeed warranted because it allows the print system to better keep track of which printer is next in line when the others are busy or otherwise offline. You can think of this in terms of connecting printers to multiple parallel ports—of course you would start with LPT1 and then move to LPT2.
Changing the print processor
When you install a printer in Windows XP using a CD that came with the printer, chances are good that the installation procedure will install the manufacturer's print processor along with the printer drivers. When this happens, the default Windows print processor is relegated to second fiddle. This is a normal occurrence and, in most cases, the OEM print processor will work fine.
Basically, the job of the print processor is to work as an intermediary between the print spooler and the printer. In this teamwork setting, the spooler receives a print job, converts it into a spool file, then monitors the current print jobs and the target printer to determine an appropriate time to print a job.
Once the spooler determines that a job should be printed, it calls the print processor and hands off the spooled print job. The print processor then converts the spooled data into a format that can then be sent to the actual printer. In addition, the print processor is responsible for handling requests to pause, resume, and cancel print jobs.
In most cases, the OEM print processor is designed to work with a single printer and doesn't have any means of properly communicating with a printer pool. So perhaps it's not surprising that, in my experience, the most common cause of a malfunctioning printer pool is an OEM print processor. Fortunately, it's easy to switch back to the default Windows print processor, which is designed to communicate with a printer pool.
To change the print processor, access the Printer And Faxes window, right-click on the first printer that you installed, and select Properties. When you see the Properties dialog box, select the Advanced tab, as shown in Figure A.
|You'll access the print processor configuration settings from the Advanced tab of the printer's Properties dialog box.|
Click the Print Processor button near the bottom of the dialog box. You'll then see the Print Processor dialog box. At this point, select WinPrint in the Print Processor list and RAW in the Default Data Type list, as shown in Figure B.
|You'll want to select the WinPrint print processor and the RAW data type.|
As you can see, the Default Data Type list contains several Spool data types. Of these, the RAW format makes the best choice because it contains printer-specific information and can be sent to the printer without further processing.
To complete the change, click OK. You'll then need to change the print processor for each of the printers that you've installed.
Creating the printer pool
Once you've made all the necessary preparations, creating the actual printer pool is very easy. To get started, access the Printer And Faxes window, right-click on the first printer that you installed, and select the Properties command. When you see the Properties dialog box, select the Ports tab. Next, select the Enable Printer Pooling check box near the bottom of the dialog box. Then, scroll through the ports list box and select the check boxes for the ports to which the printers in the pool are connected, as shown in Figure C. Then click OK.
|Creating the actual printer pool is just a matter of selecting a few check boxes.|
You'll then access the Ports tab for each of the other printers in the pool and repeat the last two steps of selecting the Enable Printer Pooling check box and the check boxes for the ports to which the printers in the pool are connected.
Using the printer pool
At this point, you're printer pool is ready for use. Users on the network will now select the printer pool as the default printer and begin using it to print their documents. When multiple documents are concurrently sent to the printer pool, the first document to arrive will begin printing on the first printer, the second document to arrive will begin printing on the second printer, and so on. If all of the printers are busy, other documents will line up in the queue and then be sent to the first available printer.
Keep in mind that if a printer malfunctions or runs out of paper, any document sent to the printer at the time the problem occurred will remain in the queue until the problem is solved and that printer is working again. Any documents arriving while that printer is down will be routed to the other printers in the pool.
Greg Shultz is a freelance Technical Writer. Previously, he has worked as Documentation Specialist in the software industry, a Technical Support Specialist in educational industry, and a Technical Journalist in the computer publishing industry.