Table of Contents
•
•
Escape commands are addressed to the scanner via "Application Work Groups."
Once a command is sent, all scanners in a group respond to that command.
Because of this, it is recommended that each scanner is assigned to its own
group in Host ACK mode.
The commands to which the scanner responds are listed on
1B in hex. A typical command string is y [ESC] x, where "y" is the application work
group number, "[ESC] x" is the escape command, and the comma is the terminator,
which is required. (When "y" is not specified, the command is sent to the default
Application Work Group 0.)
Example: Commands may be strung together to create custom response sequences. An
example of a command string is listed below.
[ESC]4,[ESC]5,[ESC]6,
The above example will make a scanner that is in application work group zero beep
low, then medium, then high.
Example: A good read beep is required for any item on file, but a razz or error tone is required
if the item is not on file. In this case,
[ESC]7, is sent from the host to the scanner for an on-file product
[ESC]8,[ESC]8, is sent from the host to the scanner for a not-on-file product
When a bar code is scanned, the scanner enters a timeout period until either the
host ACK sequence is received, or the timeout expires (in 10 seconds, by default).
Once Host ACK is enabled, the system works as follows when a bar code is
scanned:
•
•
•
A time-out occurs if the scanner does not receive a valid escape command within
10 seconds. A time-out is indicated by an error tone. If a time-out occurs, the oper-
ator should check the host system to understand why a response to the scanner
was not received.
Xenon/Granit User Guide
A comma must be used as a terminator.
The host terminal software must be capable of interpreting the bar code data,
make decisions based on the data content, and send out appropriate escape
commands to the scanner.
The scanner reads the code and sends data to the base or Access Point to
transmit to the host system. No audible or visual indication is emitted until the
scanner receives an escape command. The scanner read illumination goes out
when there's a successful read.
Scanner operation is suspended until 1) a valid escape string is received from
the host system or 2) the scanner times out.
Once condition 1 or 2 above has been met, the scanner is ready to scan again,
and the process repeats.
page
80. The [ESC] is a
79
Table of Contents
