FEED Self Test

Different types of media may require different darkness settings. This section contains a simple but effective method for determining the ideal darkness for printing bar codes that are within specifications.

During the FEED self test, labels are printed at different darkness settings at two different print speeds. The relative darkness and the print speed are printed on each label. The bar codes on these labels may be ANSI-graded to check print quality.

During this test, one set of labels is printed at 2 ips, and another set is printed at 6 ips. The darkness value starts at three settings lower than the printer’s current darkness value (relative darkness of –3) and increase until the darkness is three settings higher than the current darkness value (relative darkness of +3).

Print a configuration label to show the printer’s current settings.

Turn off (O) the printer.

Press and hold

FEED

while turning on (I) the printer. Hold

FEED

until the first control panel light turns off.

The printer prints a series of labels at various speeds and at darkness settings higher and lower than the darkness value shown on the configuration label.

Inspect these test labels and determine which one has the optimal print quality for your application. If you have a bar code verifier, use it to measure bars/spaces and calculate the print contrast. If you do not have a bar code verifier, use your eyes or the system scanner to choose the optimal darkness setting based on the labels printed in this self test.

Judging Bar Code Quality
Print Quality	Description
Too dark	Labels that are too dark are fairly obvious. They may be readable but not in‑spec. The normal bar code bars increase in size. The openings in small alphanumeric characters may fill in with ink. Rotated bar code bars and spaces run together.
Slightly dark	Slightly dark labels are not as obvious. The normal bar code will be in-spec. Small character alpha numerics will be bold and could be slightly filled in. The rotated bar code spaces are small when compared to the in-spec code, possibly making the code unreadable.
In-spec	The in-spec bar code can only be confirmed by a verifier, but it should exhibit some visible characteristics. The normal bar code will have complete, even bars and clear, distinct spaces. The rotated bar code will have complete, even bars and clear, distinct spaces. Although it may not look as good as a slightly dark bar code, the bar code will be in-spec. In both normal and rotated styles, small alphanumeric characters look complete.
Slightly light	Slightly light labels are, in some cases, preferred to slightly dark ones for in-spec bar codes. Both normal and rotated bar codes will be in spec, but small alphanumeric characters may not be complete.
Too light	Labels that are too light are obvious. Both normal and rotated bar codes have incomplete bars and spaces. Small alphanumeric characters are unreadable.

Note the relative darkness value and the print speed printed on the best test label.

Add or subtract the relative darkness value from the darkness value specified on the configuration label. The resulting numeric value is the optimal darkness value for that specific label/ribbon combination and print speed.

If necessary, change the darkness value to the darkness value on the selected test label.

If necessary, change the print speed to the same speed as on the selected test label.