4
6
Parameter Description
Parameter Description
Step 4. The inverter responds to the computer using format C after receiving and processing the data.
ACK
Station Number
0
CR
H06
H30 H30
H0D
Example 5.
Change the value of
P.195
to 500 (parameter range 0~400):
Step1 and step 2 of Example 5 are similar to Step1 and Step2 of Example 3.
Step 3. The computer requests the inverter to enter 500 into P.195 via format A:
ENQ
Station Number
0
Command Code
HDF
Waiting Time
Data
HC350
Sum Check
CR
H05
H30 H30
H44 H46
H30
H43 H33 H35 H30
H46 H35
H0D
Step 4. After processing, the inverter will send feedbacks about the out of range data (i.e., incorrect
data) to the computer via format D:
NAK
Station Number
0
Error Code
H0C
CR
H15
H30 H30
H43
H0D
2. Modbus protocol
1). Information form
Modbus serial transmission can be divided into two kinds: ASCII (American Standard Code for
Information Interchange) and RTU (Remote Terminal Unit) modes.
(1). Query
The computer (primary address) sends a message to the inverter (from the address) with the
specified address.
(2). Normal response
After receiving the query from the computer, the inverter performs the requested function from
the computer and return to the normal function.
(3). Error response
If the inverter receives an invalid function code, address, or data, it will send feedback to the
computer.
Query Msssage
PC
（
Master
）
INV
（
Slave
）
Single
Response Message
ASCII
：
CR
、
LF
RTU
：
wait times >= 10ms
Response time for
INV
Query Messsage
PC
（
Master
）
INV
（
Slave
）
Broadcast
No Response
