# `file_message` — File Modbus Messages

## API Documentation

### File Record Read/Write Messages

Currently none of these messages are implemented

class `pymodbus.file_message.``FileRecord`(**kwargs)

  Represents a file record and its relevant data.

  `__init__`(**kwargs)

    Initializes a new instance

    Params reference_type:
    | Defaults to 0x06 (must be)
    Params file_number:
    | Indicates which file number we are reading
    Params record_number:
    | Indicates which record in the file
    Params record_data:
    | The actual data of the record
    Params record_length:
    | The length in registers of the record
    Params response_length:
    | The length in bytes of the record

  `__eq__`(relf)

    Compares the left object to the right

  `__ne__`(relf)

    Compares the left object to the right

  `__repr__`()

    Gives a representation of the file record

class `pymodbus.file_message.``ReadFileRecordRequest`(records=None, **kwargs)

  This function code is used to perform a file record read. All request data lengths are provided in terms of number of bytes and all record lengths are provided in terms of registers.

  A file is an organization of records. Each file contains 10000 records, addressed 0000 to 9999 decimal or 0x0000 to 0x270f. For example, record 12 is addressed as 12. The function can read multiple groups of references. The groups can be separating (non-contiguous), but the references within each group must be sequential. Each group is defined in a seperate ‘sub-request’ field that contains seven bytes:

      The reference type: 1 byte (must be 0x06)
      The file number: 2 bytes
      The starting record number within the file: 2 bytes
      The length of the record to be read: 2 bytes

  The quantity of registers to be read, combined with all other fields in the expected response, must not exceed the allowable length of the MODBUS PDU: 235 bytes.

  `__init__`(records=None, **kwargs)

    Initializes a new instance

    Parameters: | records – The file record requests to be read

  `encode`()

    Encodes the request packet

    Returns: | The byte encoded packet

  `decode`(data)

    Decodes the incoming request

    Parameters: | data – The data to decode into the address

  `execute`(context)

    Run a read exeception status request against the store

    Parameters: | context – The datastore to request from
    Returns: | The populated response

class `pymodbus.file_message.``ReadFileRecordResponse`(records=None, **kwargs)

  The normal response is a series of ‘sub-responses,’ one for each ‘sub-request.’ The byte count field is the total combined count of bytes in all ‘sub-responses.’ In addition, each ‘sub-response’ contains a field that shows its own byte count.

  `__init__`(records=None, **kwargs)

    Initializes a new instance

    Parameters: | records – The requested file records

  `encode`()

    Encodes the response

    Returns: | The byte encoded message

  `decode`(data)

    Decodes a the response

    Parameters: | data – The packet data to decode

class `pymodbus.file_message.``WriteFileRecordRequest`(records=None, **kwargs)

  This function code is used to perform a file record write. All request data lengths are provided in terms of number of bytes and all record lengths are provided in terms of the number of 16 bit words.

  `__init__`(records=None, **kwargs)

    Initializes a new instance

    Parameters: | records – The file record requests to be read

  `encode`()

    Encodes the request packet

    Returns: | The byte encoded packet

  `decode`(data)

    Decodes the incoming request

    Parameters: | data – The data to decode into the address

  `execute`(context)

    Run the write file record request against the context

    Parameters: | context – The datastore to request from
    Returns: | The populated response

class `pymodbus.file_message.``WriteFileRecordResponse`(records=None, **kwargs)

  The normal response is an echo of the request.

  `__init__`(records=None, **kwargs)

    Initializes a new instance

    Parameters: | records – The file record requests to be read

  `encode`()

    Encodes the response

    Returns: | The byte encoded message

  `decode`(data)

    Decodes the incoming request

    Parameters: | data – The data to decode into the address

class `pymodbus.file_message.``ReadFifoQueueRequest`(address=0, **kwargs)

  This function code allows to read the contents of a First-In-First-Out (FIFO) queue of register in a remote device. The function returns a count of the registers in the queue, followed by the queued data. Up to 32 registers can be read: the count, plus up to 31 queued data registers.

  The queue count register is returned first, followed by the queued data registers. The function reads the queue contents, but does not clear them.

  `__init__`(address=0, **kwargs)

    Initializes a new instance

    Parameters: | address – The fifo pointer address (0x0000 to 0xffff)

  `encode`()

    Encodes the request packet

    Returns: | The byte encoded packet

  `decode`(data)

    Decodes the incoming request

    Parameters: | data – The data to decode into the address

  `execute`(context)

    Run a read exeception status request against the store

    Parameters: | context – The datastore to request from
    Returns: | The populated response

class `pymodbus.file_message.``ReadFifoQueueResponse`(values=None, **kwargs)

  In a normal response, the byte count shows the quantity of bytes to follow, including the queue count bytes and value register bytes (but not including the error check field). The queue count is the quantity of data registers in the queue (not including the count register).

  If the queue count exceeds 31, an exception response is returned with an error code of 03 (Illegal Data Value).

  classmethod `calculateRtuFrameSize`(buffer)

    Calculates the size of the message

    Parameters: | buffer – A buffer containing the data that have been received.
    Returns: | The number of bytes in the response.

  `__init__`(values=None, **kwargs)

    Initializes a new instance

    Parameters: | values – The list of values of the fifo to return

  `encode`()

    Encodes the response

    Returns: | The byte encoded message

  `decode`(data)

    Decodes a the response

    Parameters: | data – The packet data to decode