3nStar SC050, Technical Manual

Page: 13 / 78

11
2.2 Serial port command instructions
Table 2.2-1 Serial Port Command Data Format
Length
Message
Source
Message
target
Reserve Opcode Command Beeper
Check
Sum
Table 2.2-2 Serial Port Command Data Analysis
Field Format Sub-Field Description
Length 1 Byte Length
Command length,
excluding Check Sum,
maximum value is 0xFF.
Message
Source
1 Byte
0x04=Host (PC or industrial
computer);
0x31= Decoder (barcode scanner)
Command source
Message
target
1 Byte
0x04=Host (PC or industrial
computer);
0x31=Decoder (barcode scanner)
Command target address
Reserve 1Byte Reserved (0x00)
Opcode 1Byte
Op-code command
function table
Command
Variable
number
of bytes
Beeper 1 Byte
0x31=Enable
0xFF=Disable
Buzzer status
Check
Sum
2 Byte
Message check sum
format High byte
low byte
Note:
1. Check Sum: Radix complement of command sum, high byte in the beginning and
low byte in the end.
Check digit calculation method: Adding up all bytes to get sum before checking
(excluding two check digit bytes). Check digit value=Sum reversed as per digit then
add one.
Example: Save & Exit (0A 04 31 00 24 25 45 4E 44 FF) adding up to obtain the
sum: 02 5E, switch to binary (0000 0010 0101 1110), then reverse (1111 1101 1010
0001), finally add one is check digit (FD A2).
2. When Command uses character in the following data format pack (prefix excluding
“0x”) and be sent via serial port command, it should switch character to Hex of ASCII
code accordingly.