Read/
Function name
write
Read holding register
Read
access log
4.5.6
Read Holding Register (reading of data of holding registers) (H03 or 03)
• Query message
a.
b. Function
Slave Address
H03
(8 bits)
(8 bits)
• Normal response (Response message)
a.
b. Function
Slave Address
H03
(8 bits)
(8 bits)
Code
The number of registers that were successfully accessed by
the previous communication is read.
Queries by function codes H03 and H10 are supported.
H46
The number and start address of holding registers successfully
accessed by the previous communication are returned.
"0" is returned for both the number and start address for
queries other than function code H03 and H10.
c. Starting Address
H
L
(8 bits)
(8 bits)
e. Byte Count
H
(8 bits)
(8 bits)
Outline
d. No. of Points
H
L
L
(8 bits)
(8 bits)
(8 bits)
f. Data
L
...
(n 16 bits)
(8 bits)
Message
Broadcast
format
communication
reference
page
Not available
74
CRC Check
H
(8 bits)
CRC Check
L
H
(8 bits)
(8 bits)
PARAMETER
4
67