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AD-4411
10.3.2. Example message for holding register
The following is an example reading contiguous data of the Gross Value (data address 400003~400004) and
Net Value (data address 400005~400006).
Master -> Slave
0x01 03 00 02 00 04 E5 C9
Slave address
0x01
Set 0x01 (Slave address 01) in this example.
Function code
0x03
Set 0x03, which is a request to read the data address
400001~465535 (holding registers).
Starting data address
0x00 02 The Modbus protocol specifies that the starting data address be set
to the value of the holding register data address minus 400001, so
in this example set 0x0002 (= 400003 – 400001)
Read data points
0x00 04 In this example, set 0x04 to read 4 data from 400003 to 400006.
CRC
0x E5 C9 An error-checking field is based on a CRC method.
Slave -> Master
0x01 03 08 86 9F 00 01 C3 4F 00 00 42 C7
Slave address
0x01
The slave address is echoed back as is.
Function code
0x03
The function code is echoed back as is.
Number of read data bytes 0x08
The number of read data bytes is set.
Data 1
0x86 9F The data in 400003 The master can read the first 16-bit data as
the low data of 32-bit value.
In this example, the current gross value is
99999 (= 0x00 01 86 9F).
Data 2
0x00 01 The data in 400004
Data 3
0xC3 4F The data in 400005 In this example, the current net value is 49999
(= 0x00 00 C3 4F)
Data 4
0x00 00 The data in 400006
CRC
0x42 C7 An error-checking field is based on a CRC method.
Summary of Contents for AD-4411
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