client.sync — Twisted Synchronous Modbus Client¶
API Documentation¶
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class
pymodbus.client.sync.BaseModbusClient(framer, **kwargs)¶ Inteface for a modbus synchronous client. Defined here are all the methods for performing the related request methods. Derived classes simply need to implement the transport methods and set the correct framer.
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__enter__()¶ Implement the client with enter block
Returns: The current instance of the client
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__exit__(klass, value, traceback)¶ Implement the client with exit block
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__init__(framer, **kwargs)¶ Initialize a client instance
Parameters: framer – The modbus framer implementation to use
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__str__()¶ Builds a string representation of the connection
Returns: The string representation
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_recv(size)¶ Reads data from the underlying descriptor
Parameters: size – The number of bytes to read Returns: The bytes read
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_send(request)¶ Sends data on the underlying socket
Parameters: request – The encoded request to send Returns: The number of bytes written
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close()¶ Closes the underlying socket connection
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connect()¶ Connect to the modbus remote host
Returns: True if connection succeeded, False otherwise
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execute(request=None)¶ Parameters: request – The request to process Returns: The result of the request execution
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class
pymodbus.client.sync.ModbusTcpClient(host='127.0.0.1', port=502, framer=<class 'pymodbus.transaction.ModbusSocketFramer'>, **kwargs)¶ Implementation of a modbus tcp client
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__init__(host='127.0.0.1', port=502, framer=<class 'pymodbus.transaction.ModbusSocketFramer'>, **kwargs)¶ Initialize a client instance
Parameters: - host – The host to connect to (default 127.0.0.1)
- port – The modbus port to connect to (default 502)
- source_address – The source address tuple to bind to (default (‘’, 0))
- timeout – The timeout to use for this socket (default Defaults.Timeout)
- framer – The modbus framer to use (default ModbusSocketFramer)
Note
The host argument will accept ipv4 and ipv6 hosts
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__str__()¶ Builds a string representation of the connection
Returns: The string representation
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_recv(size)¶ Reads data from the underlying descriptor
Parameters: size – The number of bytes to read Returns: The bytes read
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_send(request)¶ Sends data on the underlying socket
Parameters: request – The encoded request to send Returns: The number of bytes written
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close()¶ Closes the underlying socket connection
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connect()¶ Connect to the modbus tcp server
Returns: True if connection succeeded, False otherwise
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class
pymodbus.client.sync.ModbusUdpClient(host='127.0.0.1', port=502, framer=<class 'pymodbus.transaction.ModbusSocketFramer'>, **kwargs)¶ Implementation of a modbus udp client
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__init__(host='127.0.0.1', port=502, framer=<class 'pymodbus.transaction.ModbusSocketFramer'>, **kwargs)¶ Initialize a client instance
Parameters: - host – The host to connect to (default 127.0.0.1)
- port – The modbus port to connect to (default 502)
- framer – The modbus framer to use (default ModbusSocketFramer)
- timeout – The timeout to use for this socket (default None)
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__str__()¶ Builds a string representation of the connection
Returns: The string representation
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classmethod
_get_address_family(address)¶ A helper method to get the correct address family for a given address.
Parameters: address – The address to get the af for Returns: AF_INET for ipv4 and AF_INET6 for ipv6
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_recv(size)¶ Reads data from the underlying descriptor
Parameters: size – The number of bytes to read Returns: The bytes read
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_send(request)¶ Sends data on the underlying socket
Parameters: request – The encoded request to send Returns: The number of bytes written
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close()¶ Closes the underlying socket connection
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connect()¶ Connect to the modbus tcp server
Returns: True if connection succeeded, False otherwise
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class
pymodbus.client.sync.ModbusSerialClient(method='ascii', **kwargs)¶ Implementation of a modbus serial client
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static
_ModbusSerialClient__implementation(method)¶ Returns the requested framer
Method: The serial framer to instantiate Returns: The requested serial framer
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__init__(method='ascii', **kwargs)¶ Initialize a serial client instance
The methods to connect are:
- ascii - rtu - binary
Parameters: - method – The method to use for connection
- port – The serial port to attach to
- stopbits – The number of stop bits to use
- bytesize – The bytesize of the serial messages
- parity – Which kind of parity to use
- baudrate – The baud rate to use for the serial device
- timeout – The timeout between serial requests (default 3s)
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__str__()¶ Builds a string representation of the connection
Returns: The string representation
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_recv(size)¶ Reads data from the underlying descriptor
Parameters: size – The number of bytes to read Returns: The bytes read
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_send(request)¶ Sends data on the underlying socket
If receive buffer still holds some data then flush it.
Sleep if last send finished less than 3.5 character times ago.
Parameters: request – The encoded request to send Returns: The number of bytes written
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close()¶ Closes the underlying socket connection
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connect()¶ Connect to the modbus serial server
Returns: True if connection succeeded, False otherwise
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static