Eastron SDM530-MT, Руководство пользователя

Страница: 42 / 45

- 21 -
Field Name Example(Hex)
Slave Address 01
Function 04
Starting Address High 00
Starting Address Low 00
Number of Points High 00
Number of Points Low 02
Error Check Low 71
Error Check High CB
Note: Data must be requested in register pairs i.e. the “Starting Address“ and the “Number of
Points” must be even numbers to request a floating point variable. If the “Starting Address” or
the “Number of points” is odd then the query will fall in the middle of a floating point variable
the product will return an error message.
The following response returns the contents of Volts 1 as 230.2. But see also “Exception
Response” later.
Field Name Example (Hex)
Slave Address 01
Function 04
Byte Count 04
Data, High Reg, High Byte 43
Data, High Reg, Low Byte 66
Data, Low Reg, High Byte 33
Data, Low Reg, Low Byte 34
Error Check Low 1B
Error Check High 38
3.9 Holding Registers
3.9.1 Read Holding Registers
MODBUS Protocol code 03 reads the contents of the 4X registers.
Example
The following query will request the prevailing ‘Demand Time’:
Field Name Example (Hex)
Slave Address 01
Function 03
Starting Address High 00
Starting Address Low 00
Number of Points High 00
Number of Points Low 02
Error Check Low C4
Error Check High 0B
Note: Data must be requested in register pairs i.e. the “Starting Address“ and the “Number of
www.stromzähler.eu