Point-to-Point
It is a basic RS-232C communication protocol that does not control communication by a control
code.
Code
R
eader
External device
Character notation
Hex notation
Serial Trigger command
<
3C
20
>
3E
Read result
1
31
2
32
3
33
In Read Cycle
4
34
5
35
CR
0D
LF
0A
Character notation
Hex notation
Point-to-Point with XOn/XOff
With this protocol, if the free space of the Receive buffer on the side receiving data becomes small,
it sends XOff (Hex:13) to the Data Transmit side to request transmission interrupt. When it has
enough free space again, it sends XOn (Hex:11) to the Data Transmit side to request Re-transmit.
Code
Reader
External device
Character notation
Hex notation
Request transmission interrupt
XOff
13
Serial Trigger command
<
3C
20
>
3E
Character notation
Hex notation
Read result
1
31
2
32
3
33
4
34
5
35
CR
0D
LF
0A
Request re-transmit
XOn
11
In Read Cycle
If XOff is received, data is not output until XOn is received.
ACK/NAK
ACK/NAK Control Codes are an RS-232C communication protocol for confirming communication.
When data is received, an ACK (Hex:06) response is sent to the device that sent the data. When
data is not successfully received, a NAK (Hex:15) response is sent to the device that sent the data.
If the device that sent the data receives a NAK response, it re-transmits its data.
When the data was successfully received:
Character notation
Hex notation
Serial Trigger command
<
3C
20
>
3E
ACK response
ACK
06
Read result
1
31
2
32
3
33
In Read Cycle
4
34
5
35
CR
0D
LF
0A
06
ACK response
ACK
Code
Reader
External device
Character notation
Hex notation
When the data was not received:
NAK response
NAK
15
Read result
1
31
2
32
3
33
In Read Cycle
4
34
5
35
CR
0D
LF
0A
Read result
1
31
2
32
3
33
4
34
5
35
CR
0D
LF
0A
When NAK is received, previous Output data is re-sent.
ACK response
ACK
06
Character notatiion
Hex notatiion
Serial Trigger command
<
3C
20
>
3E
06
ACK response
ACK
Code
Reader
External device
Character notatiion
Hex notatiion
5
Controlling Operation and Data Output with RS-232C
5
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V430-F Series Autofocus Multicode Reader User Manual for Communication Settings