Datalogic Scanning 90ACC1780 manual Fifo, ACK/NACK enabled, 118

5 GRYPHON™

GRYPHON M

data	data
	cable
OM-GRYPHON™	NACK	Host
good RX	data
beep
	ACK
ACK/NACK enabled

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. 5.7.1 for M-Series readers.

Selection of the ACK/NACK protocol temporarily disables FIFO buffering see par. 5.1.3.

5.1.3FIFO

GRYPHON™ D 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 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™ M blocks message transmission until the OM-GRYPHON™ has completed transmission towards the Host.

118