Datalogic PreScan, Advanced Configuration Manual

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Magellan Configuration
34 PreScan™ Queue-Busting System
Basket Download Timing and Options
There are three PreScan options that are used to tune the basket download timing relative to the
abilities of the POS. They also determine how quickly the POS must respond when handling
exception cases such as not-on-file labels or items that require age verification. The three options
are:
1. First Label in Transaction Delay - This option allows a longer delay to be accepted for the
first label sent to the POS during a basket download. Many POS systems have extra trans-
action-related work that gets performed when the first label is received. This extra process-
ing may cause a delayed response from the POS when handling an exception item like a
not-on-file label or an item that requires age verification. This configurable delay is used
to provide extra time for processing the first label while not affecting the throughput for
second and subsequent labels.
2. Basket Download Inter-label Delay - This option determines the rate at which labels are
downloaded from the base station and transmitted to the POS. It is applied to the second
and subsequent labels in a PreScan basket.
3. Base Station Response Delay - This configuration setting determines how long the Magel-
lan will wait for a response from the base station once a basket download has been started.
It also determines how long the Magellan will remain disabled for normal scanning when
a basket ID label is read and processed.
The style and behavior of the POS terminal must be considered when adjusting these settings.
They must be set high enough to give the POS enough time to respond with a disable command
when an exception item is sent but they should be set as low as possible to improve throughput
during the basket download. POS terminals may be loosely grouped into two types: ones that
send a disable and enable command following every label and ones that only send disable
commands when an exceptional label is received. The PreScan system can be configured for
each of these POS types.
For POS terminals that send disable and enable commands following every label, the enable
command is taken as confirmation that the POS is ready to accept another label. The inter-label
delay is cleared when the enable command is received and the next label is sent immediately. In
these environments, the POS determines the overall throughput during the basket download
because it provides positive confirmation (the enable command) that it is ready for the next
label.
For POS terminals that only send disable and enable commands when exception labels are
received, the overall throughput of the basket download is determined by the PreScan Inter-
label delay. If no disable command is received before the inter-label delay expires then the next
label is sent automatically and the inter-label timer is restarted. If an exception is encountered
and the POS sends a disable command to the scanner then the inter-label delay is cleared and
the scanner waits until an enable command is received before transmitting the next label and
restarting the inter-label delay.
Values for the three configuration items are in 100s of milliseconds.