Cino FA470 - Manual (Page 11)

Command Overview
1-4
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1.2 Command Structure
Packet Format
The following table shows the general packet format of FuzzyScan Serial Command.
Prefix Opcode Status Length Parameter(s) Check Digit Suffix
1 Byte 3 Bytes 1 Byte 2 Bytes Variable
1 Byte LRC or
2 Bytes CRC16
1 Byte
Field Name Size Descriptions
Prefix 1 Byte Fixed, “7Eh”
Opcode 3 Bytes Operation code to identifies each command
Status 1 Byte Bit 2 ACK/NAK
0 = Request
1 = Do not request
Bit 4 Check Digit
0 = LRC (1 Byte)
1 = CRC16 (2 Bytes) ( See Notes )
Bit 5 Continuation
0 = Last packet
1 = Intermediate packet
Other Bits
Reserved. ( Always 0)
Length 2 Bytes Total bytes amount of the Parameter(s) field
Formatted as High Byte Low Byte.
Length = Low Byte + High Byte x 256
If Parameter(s) = null, Length = 00h, 00h.
Parameter(s) Variable See next paragraph
1 Byte LRC: “Opcode” XOR “Status” XOR “Length” XOR “Parameter(s)”
Check Digit
2 Bytes CRC16: From “Opcode” to “Parameter(s)” ( See Notes )
Suffix 1 Byte Fixed, “7Eh”
.
Notes
CRC16 Check Digit is only used in image command which is sent from scanner to host.
Functional Group Command Name Supported Scanner Message Source
Device ACK All Series Scanners Device
Device NAK All Series Scanners Device
Host ACK All Series Scanners Host
Host NAK All Series Scanners Host
Host ACK Extension Wi-Fi Scanners Host
Acknowledgement
Host ACK Extension Wi-Fi Scanners Host