Chapter 2 Bar Code Failures
Bar Code Failures
The validator tells the printer to announce a fault condition in two situations:
•if the validator detects a bad bar code
•if the validator detects no bar code where it expects to find one.
How the printer reacts to these faults is determined by the printer’s configuration settings, as described below.
Bad Bar Code Error Detection
The validator examines every bar code that passes under the scanning beam and sends an analysis report to the printer. If a bar code is reported to have failed to meet any of the acceptance criteria, an error condition is reported. How the printer then reacts is described in “Error Action” on page 79.
Missing Bar Code Error Detection
A bar code may print so poorly that the validator cannot detect it, and the printer does not receive an analysis report for the code. To catch this problem, the printer tracks the position of the last label printed and knows when it should have completely passed the scanning beam. It can then compare the number of bar code analysis reports it expected to the number it received. If the printer does not receive enough bar code reports, it enters an error condition. How the printer then reacts is described in “Error Action” on page 79.
The number of bar codes expected is determined one of two ways:
•If Auto is selected for the Number of Codes parameter, and you are using LinePrinter Plus®, IGP®/PGL®, IGP Code V™, or IPDS™ graphics software, the printer compares the number of bar code commands it receives from the software to the number of analysis reports it receives from the validator.
•You can set the number of bar codes generated by a bitmapped image that the printer should expect per form by selecting a value in the Number of Codes parameter.
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