Others (Word Type); Modbus Communication; Read Input Registers (Function 0X04) - Brainchild PR10 User Manual

Replace B Value in Equation 2 to find A Value
Modbus Scale High =1.2B-0.2A
Modbus Scale High =1.2*((Modbus Scale Low+(6*Modbus Scale High))/7)-0.2A
0.2A=1.2*((Modbus Scale Low+(6*Modbus Scale High))/7)-Modbus Scale High
A=(1.2*((Modbus Scale Low+(6*Modbus Scale High))/7)-Modbus Scale High)/0.2--------------Equation 5
8.1.3.4

Others (Word Type)

Modbus Address
11001
11002
Note:
Value
0
1
2
3

8.2 Modbus Communication

8.2.1

Read Input Registers (Function 0x04)

The function code is used to read from 1 to 120 contiguous input registers in remote device.
Query
The query message specifies the starting register and quantity of registers to be read. Registers
are addressed starting at zero: register 1 – 16 are addressed as 0 – 15.
Here is an example of a request to read register 0 (register type is Input Register, address is 1) from
slave device 1:
Field Name
Slave Address
Starting Address Hi
Starting Address Lo
Quantity of Registers Hi
Quantity of Registers Lo
Error Check Lo
Error Check Hi
Total Bytes
Response
The register data in the response message are packed as two bytes per registers, with the
binary contents right justified within each byte. For each register, the first byte contains the high order
bits and the second contains the low order bits.
The response is return when the data is completely assembled. Here is an example of a
response to the query on the opposite page:
Field Name
Slave Address
Byte Count
Error Check Lo
Register Name
PR Version
Plus NO.
Function
Function
Data Hi
Data Lo
Page 465 of 479
Description
Standard
Plus 1
Plus 2
Plus 3
RTU example (Hex)
01
04
00
00
00
01
31
CA
8
RTU example (Hex)
01
04
02
00
0A
39
Note Access
R
○ R
1