LS ELECTRIC SV-iS7 Series, User Manual

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Communication Function
362
Normal Response
ACK Station ID CMD Data SUM EOT
1 byte 2 bytes 1 byte n x 4 bytes 2 bytes 1 byte
Error Response
NAK Station ID CMD Error code SUM EOT
1 byte 2 bytes 1 byte 2 bytes 2 bytes 1 byte
• A request starts with ENQ and ends with EOT.
• A normal response starts with ACK and ends with EOT.
• An error response starts with NAK and ends with EOT.
• A station ID indicates the inverter number and is displayed as a two-byte ASCII-HEX string
that uses characters 0-9 and A-F.
• CMD: Uses uppercase characters (returns an IF error if lowercase characters are
encountered).
Character ASCII-HEX Command
‘R’ 52h Read
‘W’ 57h Write
‘X’ 58h Request monitor registration
‘Y’ 59h Perform monitor registration
• Data: ASCII-HEX (for example, when the data value is 3000: 3000
→
‘0’’B’’B’’8’h
→
30h 42h
42h 38h)
• Error code: ASCII-HEX (20h – 7Fh)
• Transmission/reception buffer size: Transmission=39 bytes, Reception=44 bytes
• Monitor registration buffer: 8 Words
• SUM: Checks communication errors via sum.
• SUM=a total of the lower 8 bits values for station ID, command and data (Station
ID+CMD+Data) in ASCII-HEX.
• For example, a command to read 1 address from address 3000:
SUM=‘0’+‘1’+’R’+‘3’+‘0’+‘0’+‘0’+’1’ = 30h+31h+52h+33h+30h+30h+30h+31h = 1A7h (the contr ol
value is not included: ENQ, ACK, NAK, etc.