SV-iS7 User Manual - Inverter Drive Supermarket

11.2 Communication Protocol
11.2.1 LS INV 485 protocol
Computer and other hosts are the master and the inverter is the slave.
The slave inverter responds to the master’s request for writing/reading.
Basic Form
Request::
Normal Response:
Error response:
Chapter 11 Communication Function
ENQ
Address
No.
CMD Data SUM EOT
1 byte 2 bytes 1 byte n bytes 2 bytes 1 byte
ACK
Address
No.
CMD Data SUM EOT
1 byte 2 bytes 1 byte n * 4 bytes 2 bytes 1 byte
NAK
Address
No.
CMD Error Code SUM EOT
1 byte 2 bytes 1 byte 2 bytes 2 bytes 1 byte
Description:
� Requests begin with ENQ and end with EOT.
� Normal responses begin with ACK and ends with EOT.
� Error responses begin with NAK and ends with EOT.
� Address No. refers to the inverter No. and represented by 2 byte ASCII-HEX.
(ASCII-HEX: hex representation consisting of ‘0’ ~ ‘9’, ‘A’ ~ ‘F’)
� CMD: in capitals (IF Error if in small letters)
Character ASCII-HEX Command
‘R’ 52h Read
‘W’ 57h Write
‘X’ 58h Monitor registration request
‘Y’ 59h Monitor registration implementation
� Data: represented in ASCII-HEX
E.g.) If data value is 3,000: 3000 → ‘0’’B’’B’’8’h → 30h 42h 42h 38h
11-9