Module pyModbusTCP.utils¶
This module provide a set of functions for modbus data mangling.
Bit functions¶
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pyModbusTCP.utils.get_bits_from_int(val_int, val_size=16)¶ Get the list of bits of val_int integer (default size is 16 bits)
Return bits list, least significant bit first. Use list.reverse() if need.
Parameters: - val_int (int) – integer value
- val_size (int) – bit size of integer (word = 16, long = 32) (optional)
Returns: list of boolean “bits” (least significant first)
Return type: list
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pyModbusTCP.utils.set_bit(value, offset)¶ Set a bit at offset position
Parameters: - value (int) – value of integer where set the bit
- offset (int) – bit offset (0 is lsb)
Returns: value of integer with bit set
Return type: int
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pyModbusTCP.utils.reset_bit(value, offset)¶ Reset a bit at offset position
Parameters: - value (int) – value of integer where reset the bit
- offset (int) – bit offset (0 is lsb)
Returns: value of integer with bit reset
Return type: int
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pyModbusTCP.utils.toggle_bit(value, offset)¶ Return an integer with the bit at offset position inverted
Parameters: - value (int) – value of integer where invert the bit
- offset (int) – bit offset (0 is lsb)
Returns: value of integer with bit inverted
Return type: int
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pyModbusTCP.utils.test_bit(value, offset)¶ Test a bit at offset position
Parameters: - value (int) – value of integer to test
- offset (int) – bit offset (0 is lsb)
Returns: value of bit at offset position
Return type: bool
Word functions¶
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pyModbusTCP.utils.word_list_to_long(val_list, big_endian=True, long_long=False)¶ Word list (16 bits) to long (32 bits) or long long (64 bits) list
By default word_list_to_long() use big endian order. For use little endian, set big_endian param to False. Output format could be long long with long_long option set to True.
Parameters: - val_list (list) – list of 16 bits int value
- big_endian (bool) – True for big endian/False for little (optional)
- long_long (bool) – True for long long 64 bits, default is long 32 bits (optional)
Returns: list of 32 bits int value
Return type: list
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pyModbusTCP.utils.long_list_to_word(val_list, big_endian=True, long_long=False)¶ Long (32 bits) or long long (64 bits) list to word (16 bits) list
By default long_list_to_word() use big endian order. For use little endian, set big_endian param to False. Input format could be long long with long_long param to True.
Parameters: - val_list (list) – list of 32 bits int value
- big_endian (bool) – True for big endian/False for little (optional)
- long_long (bool) – True for long long 64 bits, default is long 32 bits (optional)
Returns: list of 16 bits int value
Return type: list
Two’s complement functions¶
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pyModbusTCP.utils.get_2comp(val_int, val_size=16)¶ Get the 2’s complement of Python int val_int
Parameters: - val_int (int) – int value to apply 2’s complement
- val_size (int) – bit size of int value (word = 16, long = 32) (optional)
Returns: 2’s complement result
Return type: int
Raises: ValueError – if mismatch between val_int and val_size
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pyModbusTCP.utils.get_list_2comp(val_list, val_size=16)¶ Get the 2’s complement of Python list val_list
Parameters: - val_list (list) – list of int value to apply 2’s complement
- val_size (int) – bit size of int value (word = 16, long = 32) (optional)
Returns: 2’s complement result
Return type: list
IEEE floating-point functions¶
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pyModbusTCP.utils.decode_ieee(val_int, double=False)¶ Decode Python int (32 bits integer) as an IEEE single or double precision format
Support NaN.
Parameters: - val_int (int) – a 32 or 64 bits integer as an int Python value
- double (bool) – set to decode as a 64 bits double precision, default is 32 bits single (optional)
Returns: float result
Return type: float
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pyModbusTCP.utils.encode_ieee(val_float, double=False)¶ Encode Python float to int (32 bits integer) as an IEEE single or double precision format
Support NaN.
Parameters: - val_float (float) – float value to convert
- double (bool) – set to encode as a 64 bits double precision, default is 32 bits single (optional)
Returns: IEEE 32 bits (single precision) as Python int
Return type: int