LS RS485/Modbus-RTU - Modbus Rtu Protocol

10
* Acknowledge response:
ACK Inverter No. CMD Data SUM EOT
06h “01” ~ “1F” “Y” “XXXX…” “XX” 04h
1 2 1 n * 4 byte 2 byte 1 byte
Total byte = 7 + n * 4 = Max 39
* Negative response:
NAK Inverter No. CMD Error code SUM EOT
15h “01” ~ “1F” “Y” “**” “XX” 04h
1 2 1 2 2 1
Total byte = 9
5.1.5. Error code
Error code Display Description
ILLEGAL
FUNCTION
IF
When the command received cannot be executed in the option card.
It means that there is no corresponding command.
ILLEGAL DATA
ADDRESS
IA
When parameter address received is invalid.
When monitor is executed without Monitor Register.
ILLEGAL DATA
VALUE
ID
When the DATA received is invalid.
WRITE MODE
ERROR
WM
In case of Read Only or Write Disabled during operation.
FRAME ERROR FE When the frame size, internal Num or Sum is incorrect.
TIME OUT
ERROR
TO
When DPRAM communication does not work within a certain time.
DPRAM OFF
LINE
DO When DPRAM is Off Line.
INVALID ID
NUMBER
IN When Inverter Number is incorrect.
UNDEFINED
CONDITION
UC
Except for the above cases.
TO ※ Error: Occurs when trying to communicate while the inverter is initializing. Operates normally
after initialization.
5.2.
5.2.1.
Modbus-RTU Protocol
z Use Modbus-RTU protocol. Modbus-RTU protocol is Open protocol.
z Computer or other host acts as Master while inverters act as slaves. The inverter responds to
Read/Write command from Master.
Available Function code
Function code Description
0x03 Read Hold Register
0x04 Read Input Register