Leica Biosystems IPC - Manual (Page 21)

19 Leica IP C
3.3.3 Printing bar code
Printing readable bar codes depends on various factors that need to be
taken into consideration in order to achieve results suitable for reliable and
durable archiving. The main factors influencing the bar code results are:
• printer technology
• how the bar code is created
• the type of object being printed on
• the type of scanner used to read the bar code
Printer technology
• As a dot matrix printer, this device can handle information only in the
form of dots printed or not printed. It is not possible to transmit bar code
data or to select specific bar code types or use the printer to create and
print the bar code required.
Creating bar codes
• Since there is only limited printing space on the cassettes, the bar code
should not contain more information than necessary.
• You should use an error-checking code, which makes it easier for the
bar code scanners to recognize possible errors. Some codes even sup-
port error correction.
• When calculating and creating bar code, always bear in mind the resolu-
tion of the printer.
The module size is the width of the smallest element of a bar code. Wider
bars and spaces are calculated in multiples of the module size.
The module size always has to be an entire divisor of the printer resolu-
tion, as, due to the technology applied, only 'whole' dots can be printed.
Reading errors may occur (even if the print appears to be crisp and cor-
rect), if, due to conversion, module width and resolution do not match
any longer.
3. Instrument Components and Specifications
Data should never be printed as bar code only, but also as text (line
of optical characters above or below the bar code), to ensure that
no information is lost for the above reasons.