Chapter 8. Best Practices for Tape Drives and Tape Media
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Detailed Bar Code Specifications
• Minimum symbol height is 11.1 mm, measured to the inside of the label’s edge.
• The wide-to-narrow ratio is 2.75.
• The narrow element width is 0.432 mm +0.03 mm or -0.076 mm.
• The nominal width of the wide spaces and bars is 1.188 mm.
• The inter-character gap is 0.432mm + 0.03/- 0.076 mm.
• The quiet zone at the beginning and end of a printed bar code string is 10 times the
narrow width or 4.32 mm.
• The total nominal bar code string length (including quiet zones) is 74.088 mm.
• The edge of the bar code is the edge of all printed area attached to the bar. The
edge roughness is the transition encountered as a horizontal line is moved vertically
from all black to all white. The edge roughness maximum is 0.038 mm.
• Unless otherwise specified, tolerances are X.XXX + 0.127 mm, X.XXX + 0.762 mm.
• Variation between all bars, white and black, must be less than + 0.0381 mm.
• Bar codes should be eight characters plus a checksum.
• The bar code string is printed on the label so it is on the side toward the hub.
• Label stock must fit within the label recess on the face of the cartridge without
curling up on the sides or ends (79 mm X 17 mm +0 or -0.8).
• Label stock dimensions:
• Minimum length sufficient for the quiet zones, start-stop, and data characters
(nominal 74.088 mm).
• Minimum width no less than 1.5 mm narrower than the cartridge label recess
width. Corners are cut with a 1.5 mm radius.
• The bar codes must be standard half-inch media format:
• A total of eight (8) horizontal alphanumeric characters are used for volume and
media identification.
• There must be a checksum included in the barcode.
• The minimum leading quiet zone should be 4.318mm and the maximum leading
quiet zone should be 4.318mm.
• Volume identifiers:
• Must be limited to the use of ASCII characters A-Z (41h-5Ah), 0-9 (30h-39h).
• The field consists of six (6) left-justified alphanumeric characters.
• The media identifier characters
Gg
are controlled characters.
• The
G
designates the type of data cartridge.
• The
g
indicates the generation and capacity of the cartridge.
SCSI-3 Medium Changer (SMC) Commands found in ANSI NCITS 314-199X.
