Ack/nack protocol, Fifo, 2 ack/nack protocol – Wasp Barcode WLS8600 Product Reference Guide User Manual

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4.1.2 ACK/NACK Protocol

WLS8600 Readers

This parameter sets a transmission protocol in which the Host responds to the reader

after every code transmitted. 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.

WLS8600

Host

ACK or NACK

data

cable

ACK/NACK enabled

If the reader does not receive an ACK or NACK, transmission is ended after the

RX Timeout (see par. 4.1.4).

When ACK/NACK protocol is enabled, FIFO must be disabled manually, see par.

4.1.3.

4.1.3 FIFO

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.

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