Table of Contents
Advertisement
feedback to the scan operator. The Host ACK functionality is controlled via a num-
ber of pre-defined escape commands that are sent to the scanner to make it
behave in different ways.
Note: System performance degrades when using Host ACK at rates lower than 9600 baud.
The following criteria must be met for the Host ACK to work correctly:
•
•
•
•
•
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 barcode 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 barcode is scanned:
•
74
The cordless system must be configured for Host Port RS232 (terminal ID = 000
or USB COM Emulation (terminal ID = 130).
RTS/CTS is defaulted off. You must enable it if the host system requires it.
Host ACK must be set to On
A comma must be used as a terminator.
The host terminal software must be capable of interpreting the barcode 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.
(page
75).
page
75. The [ESC] is a
Granit XP User Guide
Advertisement
Table of Contents
