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(2) Read (receive) data (slave to master)
(a) Command data are converted into ASCII code and transmitted.
(b) Comms byte quantity is 10.
(c) Comms data format (transmission sequence)
STX
1 byte
・STX (start code)
・Text data
・ETX (end code)
・SUM
(d) Text data details (transmission sequence)
Data
2 byte x 3
6 byte
・Data (note)
Note: Data transfer sequence
Data bytes
1
2
3
5. Calculation method of checksum
Example
1
STATUS
STX
02h
"01"
1. STAUTUS to DATA are transformed into hexadecimal number on the basis of the ASCII code.
'0'→30h
'1'→31h
2. STX to ETX are added all.
02h + 30h + 31h + 46h + 46h + 30h + 31h + 30h + 34h + 30h +30h + 30h + 30h + 30h + 30h + 03h ＝ 2D7h
STX STATUS
ID
3. The XOR (Exclusive OR) between the value obtained in 2 clause and FFh are taken, then two column under
the answer become SUM
Text data
6 byte
: Code indicating start of text.
1 byte (02h)
: Transmit / receive data.
6 byte (ASCII code)
: Code indicating end of text.
1 byte (03h)
: XOR result (FFh), of adding STX, Text data, and ETX.
2 byte (ASCII code)
: Sets Read data to be transmitted.
2 byte x 3 (ASCII code)
1st byte
2nd byte
Data
"00"
Upper
Lower
Upper
Mid
2
3
ID NO
AREA
ADDRES
S
"FF"
"01"
'4'→34h
'F'→46h
STX:02h
RELATIV
AREA
ETX
1 byte
10 byte
3rd byte
"00"
"00"
Lower
4
RELATIVE NO
"04"
ETX:03h
DATA
SUM
2 byte
5
6
7
DATA
ETX
"00"
"00"
"00"
03h
ETX
SUM
"28"
15
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