Fifo - Datalogic Gryphon Reference Manual

GRYPHON™ M
good RX
When ACK/NACK is enabled, the Host sends an ACK character (06 HEX) in the case
of good reception or the NACK character (15 HEX) requesting re-transmission, in the
case of bad reception. Only after the ACK character is received by the
OM-Gryphon™ does the reader respond with the good reception tone.
If the reader does not receive an ACK or NACK, transmission is ended after the RX
Timeout (see par. 5.1.4). See also Radio Protocol Timeout, par. 5.8.1 for M-Series
readers.
Selection of the ACK/NACK protocol temporarily disables FIFO buffering see par.
5.1.3.
5.1.3

FIFO

GRYPHON™ D Series Readers
This parameter determines whether data (barcodes) are buffered on a First In First
Out basis allowing faster data collection in certain cases for example when using slow
baud rates and/or hardware handshaking.
If the FIFO buffering is enabled, codes are collected and sent out on the serial line in
the order of acquisition. About 800 characters can be collected (buffer full), after
which the reader signals an error and discards any further codes until the
transmission is restored.
If the FIFO buffering is disabled, each code must be transmitted before another one
can be read.
GRYPHON™ M Series Readers
If enabled, the OM-Gryphon™ collects all messages sent by Gryphon™ M and sends
them in order of acquisition to the connected Host.
If disabled, Gryphon™
OM-Gryphon™ has completed transmission towards the Host.
data
OM-GRYPHON™
beep
ACK/NACK enabled
M blocks message
data
cable
NACK
data
ACK
transmission
REFERENCES
Host
until the
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