Amtech Axpert-Eazy Series Instruction Manual page 201

If the query is received properly then the response is returned as below.
Byte Query Bytes Description
Number
1 01h
2 03h
3 02h
4 01h
5 F4h
6 CRC Low
7 CRC High
The data received as packed data in bytes 4 and 5. Hence received value is 01F4h = 500d. So the
final value of the parameter is 500/10 = 50.0 because parameter 40003 has resolution of 1 digit after
decimal point.
5.2 Read Multiple Parameter
This query is used for single parameter read. Total 8 bytes are transmitted. 3.5-character times delay
is provided at the start and end of the query for indication of starting and ending of query.
For example if you want to read parameter 40001 to 40010 then the format of query is as below.
Byte Query Bytes Description
Number
1 01h
2 03h
3 00h
4 00h
5 00h
6 0Ah
7 CRC Low
8 CRC High
If the query is received properly then the response is returned as below.
Byte Query Bytes Description
Number
1 01h
Axpert-Eazy AC Variable Frequency Drive
section.
First byte is the address of the modbus slave device referred as station
number.
Indication of read operation
No. of data bytes packed after byte 3.
Data Byte High
Data Byte Low. Byte number 4 and 5 has right justified packed value of
the required parameter.
CRC Low Byte
CRC High Byte. The High and Low bytes are reversed in CRC
transmission. The method of calculating CRC is described in the next
section.
First byte is the address of the modbus slave device referred as station
number.
Indication of read operation
Starting address High byte
Starting Address Low byte. Parameter 40001 is addressed as 0000h.
Byte 3 and 4 has right justified packed value of parameter number.
No of parameters High Byte
No of parameters Low Byte. For 10 parameters to be read then 0Ah is
used.
CRC Low Byte
CRC High Byte. The High and Low bytes are reversed in CRC
transmission. The method of calculating CRC is described in the next
section.
First byte is the address of the modbus slave device referred as station
number.
10
11
11.13