LabelVision

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            Technical Notes

LabelVision Classic: Technical Notes

Connecting Multiple Printers
LabelVision is capable of printing to several printers connected to the same computer. This note describes how to set up multiple printers, and how LabelVision chooses on which printer a particular label is printed.

Connecting The Printers
Each printer must be connected to a different port on your computer. Although you can use either serial or parallel ports, only serial ports can have two-way communication. You must set up each printer using the Printer Setup dialog box from the Print Program or Application Editor.

Note that LabelVision supports three Parallel ports on all IBM compatible PCs, two serial ports (COM1 & COM2) on non-IBM PS/2 computers and four serial ports on IBM PS/2 machines.

How LabelVision Selects Printers
LabelVision always prints your labels on the specific printer for which they were designed. Therefore, if you connect different types of printers to your computer, LabelVision always prints each label on the printer for which it was designed.

If you have multiple, identical printers connected to your computer, LabelVision will (by default) ask you to select a printer each time a label is printed. LabelVision displays a list of the identical printers (with the ports they are set up for), you select one and the label is printed.

If you want LabelVision to automatically select the printer without any operator prompting, you must add the following line to your DEFAULT.INI file. For more information about editing DEFAULT.INI, see the "DOS Module Options" chapter in your LabelVision User's Guide.

AutoSelectPrinter=Yes

In this case, which printer a label is printed on depends upon the order, as follows.

The first label (in a single print session) is always printed on the first printer that was set up.
Each subsequent label is printed on the remaining printers, in the order the printers were set up, until all printers have been printed on once.
After all printers have been printed on at least once, each subsequent label is printed on the printer which printed a label with the exact same layout definition, if one exists.
If no labels with the same layout definition have been printed, then a label is printed on the "oldest" printer. The oldest printer is the one to which LabelVision has not sent a job for the longest time.

The information regarding the printer and its stock is maintained during a single print session only. As soon as you exit the print program, all memory of which labels were printed on which printers is lost.

One common requirement is to associate a particular stock with each printer, then have the labels printed according to their stock requirements. To accomplish this, you should make sure that each label that requires the same stock has the same layout definition, and that the layouts of labels which require different stocks are different from each other. Then, you must ensure that, when you first start the print program, one label of each layout type is printed in the same order as the corresponding printers were set up.

If you want to print identical labels, but have them go to different printers depending upon data in the database (or other data source), you should create two copies of the label with slightly different layouts. You can simply change the width or margins by 0.01" to make the layouts different.

Most applications which print on multiple identical printers first print a sample label for each stock, in the same order that the printers were set up. These "Print Label" items are typically followed by an "infinite" repeat loop (one that has an upper bound so large that it never terminates). The remainder of the application follows this loop.

Example
Suppose you have two Zebra Z-140 printers connected to your computer on COM1 and COM2 (which were set up in that order). The first one has 4" stock, while the second has 5" stock. You want to print four labels on these two printers: FOUR_A.LAB and FOUR_B.LAB both require the 4" stock, while FIVE_A.LAB and FIVE_B.LAB require the 5" stock. Each of the 4" labels should have identical layout definitions, as should each of the 5" labels. To accomplish this, create an application that first prints either FOUR_A or FOUR_B, then prints either FIVE_A or FIVE_B.

If your application is such that you can't control what order labels are printed, you should create a blank label for each stock. In our example, you would create BLANK_4 and BLANK_5 labels. Then, the first item in your application would be "Print BLANK_4.LAB" application item, followed immediately by "Print BLANK_5.LAB" application item. All subsequent labels printed in your application (in the current print session), regardless of their print order, would automatically be routed to the proper printer.