register_read_message
— Register Read Messages¶
API Documentation¶
Register Reading Request/Response¶
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class
pymodbus.register_read_message.
ReadRegistersRequestBase
(address, count, **kwargs)¶ Base class for reading a modbus register
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__init__
(address, count, **kwargs)¶ Initializes a new instance
Parameters: - address – The address to start the read from
- count – The number of registers to read
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__str__
()¶ Returns a string representation of the instance
Returns: A string representation of the instance
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decode
(data)¶ Decode a register request packet
Parameters: data – The request to decode
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encode
()¶ Encodes the request packet
Returns: The encoded packet
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get_response_pdu_size
()¶ Func_code (1 byte) + Byte Count(1 byte) + 2 * Quantity of Coils (n Bytes) :return:
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class
pymodbus.register_read_message.
ReadRegistersResponseBase
(values, **kwargs)¶ Base class for responsing to a modbus register read
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__init__
(values, **kwargs)¶ Initializes a new instance
Parameters: values – The values to write to
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__str__
()¶ Returns a string representation of the instance
Returns: A string representation of the instance
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decode
(data)¶ Decode a register response packet
Parameters: data – The request to decode
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encode
()¶ Encodes the response packet
Returns: The encoded packet
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getRegister
(index)¶ Get the requested register
Parameters: index – The indexed register to retrieve Returns: The request register
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class
pymodbus.register_read_message.
ReadHoldingRegistersRequest
(address=None, count=None, **kwargs)¶ This function code is used to read the contents of a contiguous block of holding registers in a remote device. The Request PDU specifies the starting register address and the number of registers. In the PDU Registers are addressed starting at zero. Therefore registers numbered 1-16 are addressed as 0-15.
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__init__
(address=None, count=None, **kwargs)¶ Initializes a new instance of the request
Parameters: - address – The starting address to read from
- count – The number of registers to read from address
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execute
(context)¶ Run a read holding request against a datastore
Parameters: context – The datastore to request from Returns: An initialized response, exception message otherwise
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class
pymodbus.register_read_message.
ReadHoldingRegistersResponse
(values=None, **kwargs)¶ This function code is used to read the contents of a contiguous block of holding registers in a remote device. The Request PDU specifies the starting register address and the number of registers. In the PDU Registers are addressed starting at zero. Therefore registers numbered 1-16 are addressed as 0-15.
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__init__
(values=None, **kwargs)¶ Initializes a new response instance
Parameters: values – The resulting register values
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class
pymodbus.register_read_message.
ReadInputRegistersRequest
(address=None, count=None, **kwargs)¶ This function code is used to read from 1 to approx. 125 contiguous input registers in a remote device. The Request PDU specifies the starting register address and the number of registers. In the PDU Registers are addressed starting at zero. Therefore input registers numbered 1-16 are addressed as 0-15.
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__init__
(address=None, count=None, **kwargs)¶ Initializes a new instance of the request
Parameters: - address – The starting address to read from
- count – The number of registers to read from address
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execute
(context)¶ Run a read input request against a datastore
Parameters: context – The datastore to request from Returns: An initialized response, exception message otherwise
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class
pymodbus.register_read_message.
ReadInputRegistersResponse
(values=None, **kwargs)¶ This function code is used to read from 1 to approx. 125 contiguous input registers in a remote device. The Request PDU specifies the starting register address and the number of registers. In the PDU Registers are addressed starting at zero. Therefore input registers numbered 1-16 are addressed as 0-15.
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__init__
(values=None, **kwargs)¶ Initializes a new response instance
Parameters: values – The resulting register values
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class
pymodbus.register_read_message.
ReadWriteMultipleRegistersRequest
(**kwargs)¶ This function code performs a combination of one read operation and one write operation in a single MODBUS transaction. The write operation is performed before the read.
Holding registers are addressed starting at zero. Therefore holding registers 1-16 are addressed in the PDU as 0-15.
The request specifies the starting address and number of holding registers to be read as well as the starting address, number of holding registers, and the data to be written. The byte count specifies the number of bytes to follow in the write data field.”
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__init__
(**kwargs)¶ Initializes a new request message
Parameters: - read_address – The address to start reading from
- read_count – The number of registers to read from address
- write_address – The address to start writing to
- write_registers – The registers to write to the specified address
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__str__
()¶ Returns a string representation of the instance
Returns: A string representation of the instance
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decode
(data)¶ Decode the register request packet
Parameters: data – The request to decode
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encode
()¶ Encodes the request packet
Returns: The encoded packet
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execute
(context)¶ Run a write single register request against a datastore
Parameters: context – The datastore to request from Returns: An initialized response, exception message otherwise
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get_response_pdu_size
()¶ Func_code (1 byte) + Byte Count(1 byte) + 2 * Quantity of Coils (n Bytes) :return:
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class
pymodbus.register_read_message.
ReadWriteMultipleRegistersResponse
(values=None, **kwargs)¶ The normal response contains the data from the group of registers that were read. The byte count field specifies the quantity of bytes to follow in the read data field.
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__init__
(values=None, **kwargs)¶ Initializes a new instance
Parameters: values – The register values to write
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__str__
()¶ Returns a string representation of the instance
Returns: A string representation of the instance
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decode
(data)¶ Decode the register response packet
Parameters: data – The response to decode
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encode
()¶ Encodes the response packet
Returns: The encoded packet
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