15
The default is no preamble. To select a preamble, scan up to 15 characters from
the "FULL ASCII MENU" on the back of the RF Laser Setup Menu, and then
scan SET when you're done. To return to the no preamble setting, scan Clear
here instead of scanning SET or any characters from the FULL ASCII MENU.
You can trim 1-15 leading characters from bar code codes by scanning a ~
(tilde -- ASCII 126) followed by a single digit, 1 through F, as part of the
Preamble. (Bar codes that are shorter than the amount-to-trim are transmitted
with no trimming.) Consider the examples in the following table to
understand how trimming works:
Bar Code Data Preamble Data Transmitted
123 XYZ XYZ123
12345678 ~3XYZ XYZ45678
12345678 ~9 12345678
12345 ~A 12345
123456 ~5 6
You can also trim selectively by bar code type. For example, you can trim 2
characters from Code 39 and a different amount from other bar code outputs. This
is done by using the bar code ID character in conjunction with the tilde (~). A
preamble of ~b2~c1 says trim 2 characters from the front of Code 39 output and
trim 1 character from the front of UPC-A. Refer to the Code 128 parameter on
page 12 for a list of the ID character associated with each bar code type.
A final use of the Preamble/Postamble is to enter a minimum/maximum length
check for bar code data read. Use the Preamble or Postamble by entering
|nnmm where "|" is ASCII 124, "nn" is the two digit minimum to be read and
"mm" is the two digit maximum to be read.
"Postamble" refers to a user-specified data string transmitted at the end of each
bar code. For instance, if you specify the postamble @@ and read data of
123456, "123456@@" would be transmitted to your computer.
The default is no postamble. To select a postamble, scan up to 15 characters
from the "FULL ASCII MENU" on the back of the Reader Setup Menu, and
then scan SET when you're done. To return to the no postamble setting, scan
CLEAR here instead of scanning SET or any characters from the FULL
ASCII MENU.
You can trim 1-15 trailing characters from bar code codes by scanning a ~ (tilde
-- ASCII 126) followed by a single hex digit, 1 through F. (Bar codes which are
shorter than the amount-to-trim are transmitted without trimming.) Consider the
examples in the following table to understand the options of the Postamble: