Opticon NLV-5201 User Manual page 62

D) ACK/NAK Control
In ACK/NAK mode, the scanner will transmit data and expects to receive one of the following
responses from the host:
Response: "ACK" (ASCII:0x06)
The scanner terminates transmission with the good-read buzzer.
Response: "NAK" (ASCII:0x15)
The scanner sends the data again.
Response: "DC1" (ASCII:0x11)
The scanner terminates transmission without the good-read or error buzzer.
Timeout
If there is no response within 1second, the scanner terminates transmission with the error buzzer.
Scanner
TxD
RxD
BUZERn
Decode
Finish
<ACK/NAK Flow chart>
Start of transmission
Transmit data
Start 1 sec. timer As configured
Response received
No
No
Timer ended
Yes
ERROR Buzzer
NLV-5201 User's Manual
1st
LabelA
Send
ACK Wait Buzzer
Yes
Response = NAK
No
Response = ACK
No
Response = DC1
No
ERROR Buzzer
END
Host System
LabelB
ACK
LabelB Read
Processing
Yes
Yes
Yes
GOOD READ Buzzer
Chapter-5
Interface
RxD
TxD
52