PSC Scanners - Manual (Page 35)

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Preamble or Postamble Selection
Preambles and Postambles are composed of up to four ASCII charac-
ters. Each ASCII character is encoded as two hexadecimal numbers.
Use the Hexadecimal Conversion Table in Appendix A to look up the
hexadecimal equivalent.
Preamble
A Preamble is a string of characters that prefixes a message that is
transmitted to the host. The sequence and number of characters in a
Preamble is determined by the type of host system. Although not all
systems require a Preamble, those which do will only receive mes-
sages with the correct Preamble. The maximum preamble length is
four characters.
KA Preamble = None*#
KB Enter Preamble
IMPORTANT
Scan Enter Preamble to enter a Preamble, then refer to the Hexadecimal
Table in Appendix A.
Postamble
A Postamble is similar to a Preamble, except that it appended to the
message which is transmitted to the host. Its maximum length is also
four characters.
NOTE
If you select a Preamble or a Postamble you must scan
four ASCII characters, even if the Preamble or Postamble
is less than four characters in length. This is done by
scanning in null (NUL) characters for the additional char-
acters. For example, if your Preamble is “AB” (in ASCII
code), scan A, then B, then two null characters, or 4,1, 4,2
0,0 0,0 hexadecimal.