11-5
CMD: Capital letter
Character ASCII-HEX Command
‘R’ 52h Read
‘W’ 57h Write
‘X’ 58h Request for monitoring
‘Y’ 59h Action for monitoring
Data: ASCII-HEX
Ex) when data value is 3000: 3000 (dec) → ‘0’ ’B’ ’B’ ’8’h → 30h 42h 42h 38h
Error code: ASCII (20h ~ 7Fh)
Receive/Send buffer size: Receive= 39 bite, Send=44 bite
Monitor register buffer: 8 Word
SUM: to check the communication error
SUM= ASCII-HEX format of lower 8 bit of (Drive No. + CMD + DATA)
Ex) Command Message (Request) for reading one address from address “3000”
ENQ Drive No CMD Address
Number of
address to read
SUM EOT
05h “01” “R” “3000” “1” “A7” 04h
1 byte 2 bytes 1 byte 4 bytes 1 byte 2 bytes 1 byte
SUM = ‘0’ + ‘1’ + ’R’ + ‘3’ + ‘0’ + ‘0’ + ‘0’ + ‘1’
= 30h + 31h + 52h + 33h + 30h + 30h + 30h + 31h
= 1A7h (Control values such as ENQ/ACK/NAK are excluded.)
z Detail communication protocol
1) Request for Read: Request for read successive ‘N’ numbers of WORD from address “XXXX”
ENQ
Drive
No
CMD Address
Number of
address to read
SUM EOT
05h
“01” ~
“1F”
“R” “XXXX” “1” ~ “8” = n “XX” 04h
1 byte 2 bytes 1 byte 4 bytes 1 byte 2 bytes 1 byte
Total bite = 12
The quotation marks (“ ”) means character.
1.1) Acknowledge Response:
ACK Drive No CMD Data SUM EOT
06h “01” ~ “1F” “R” “XXXX” “XX” 04h
1 byte 2 bytes 1 byte N * 4 bytes 2 byte 1 byte
Total bite = 7 + n * 4 = Max 39
1.2) Negative Acknowledge Response:
NAK Drive No CMD Error code SUM EOT
15h “01” ~ “1F” “R” “**” “XX” 04h
1 byte 2 bytes 1 byte 2 bytes 2 bytes 1 byte
Total bite = 9