Read Holding Register [03h]:
This function reads the contents of the specified number of consecutive holding registers
(of specified register addresses). An example follows below.
x
Reading Trip monitor 1 factor and trip frequency, current, and voltage from an
inverter having a slave address “1”
x
This example assumes the previous three trip factors are as follows:
X200
Command
D081
(factor)
D081
(frequency)
D081
(output current)
D081
(DC-bus Voltage)
Register
Number
0012h
0014h
0016h
0017h
Trip factor
Over-Current
(E03)
9.9Hz
3.0A
284V
Query:
Response:
No.
Field Name
Example
(Hex)
No.
Field Name
Exampl
e
(Hex)
1
Slave address *1
01
1
Slave address
01
2
Function code
03
2
Function code
03
3
Register start address
*3
(high order)
00
3
Data size (in bytes) *2
0C
4
Register start address
*3
(low order)
11
4
Register data 1 (high order)
00
5
Number of holding
registers (high order)
00
5
Register data 1 (high order)
03
6
Number of holding
registers(low order)
06
6
Register data 2 (high order)
00
7
CRC-16 (high order)
95
7
Register data 2 (low order)
00
8
CRC-16 (low order)
CD
8
Register data 3 (high order)
00
9
Register data 3 (low order)
63
10
Register data 4 (high order)
00
11
Register data 4 (low order)
00
12
Register data 5 (high order)
00
13
Register data 5 (low order)
1E
14
Register data 6 (high order)
01
15
Register data 6 (low order)
1C
16
CRC-16 (high order)
AF
17
CRC-16 (low order)
6D
Note 1:
Broadcasting is disabled.
Note 2:
Data is transferred by the specified number of data bytes (data size). In this
case, 6 bytes are used to return the content of three holding registers.
Note 3:
The PDU Register Number are addressed starting at zero. Therefore register
numbered “0012h” are addressed as “0011h”. Register address value
(transmitted on Modbus line) is 1 less than the Register Number.
B
11
Appe
ndix B
B
−
11
Appendix B
