Rockwell Automation 2755-G6-D Scanner with RS-232 Option - Manual (Page 60)

Message Format Parameters
Chapter 7
7–7
A preamble is a string of characters that prefixes a
message that is transmitted to the host. The preamble
may be used to identify the scanner that sent the
message. The maximum preamble length is four
ASCII characters.
KA Preamble=None*
To enter a preamble, scan the KB label, then refer to
Table 7.B to enter the four ASCII characters. The
procedure on the previous page explains how to enter
preamble characters.
KB
Preamble = 4 ASCII (8 Hex) characters
+
A postamble is similar to a preamble, except it is
appended to the message which is transmitted to the
host. Its maximum length is four ASCII characters.
LA Postamble=None *
To enter a postamble, scan the LB label, then refer to
Table 7.B to enter the four ASCII characters. The
procedure on the previous page explains how to enter
preamble characters.
LB
Postamble = 4 ASCII (8 Hex) characters
+
Preamble
Postamble