Exceptions - Classes Defining Alpaca Exceptions

This module contains the ASCOM Exception classes. They are used to represent the Alpaca-standard error codes and default error messages as input to construction of all JSON responses. The error messages may be overridden (and probably should be so as to give the most help to the app user).

DriverException is special. It takes an additional parameter, a Python Exception object, and will produce a Alpaca ErrorMessge containing the Python runtime error info.

Note

When creating an instance, the exception is automatically logged, including any overridden error message.

Exception Classes

class exceptions.ActionNotImplementedException(message: str = 'The requested action is not implemented in this driver.')

Requested Action() is not implemented

Initialize the ActionNotImplementedException object

Parameters:

  • number (int) – 0x040C (1036)

  • message (str) – ‘The requested action is not implemented in this driver.’

  • Logs ActionNotImplementedException: {message}

class exceptions.DriverException(number: int = 1280, message: str = 'Internal driver error - this should be more specific.', exc=None)
Exception Class for Driver Internal Errors

This exception is used for device errors and other internal exceptions. It can be instantiated with a captured exception object, and if so format the Alpaca error message to include line number/module or optionally a complete traceback of the exception (a config option).

Initialize the DeviceException object

Parameters:

  • number (int) – Alpaca error number between 0x500 and 0xFFF, your choice defaults to 0x500 (1280)

  • message (str) – Specific error message or generic if left blank. Defaults to ‘Internal driver error - this should be more specific.’

  • exc – Contents ‘ex’ of ‘except Exception as ex:’ If not included then only message is included. If supplied, then a detailed error message with traceback is created (see full parameter)

Notes

  • Checks error number within legal range and if not, logs this error and substitutes 0x500 number.

  • If the Python exception object is included as the 3rd argument, it constructs a message containing the name of the underlying Python exception and its basic context. If verbose_driver_exceptions is true, a complete Python traceback is included.

  • Logs the constructed DriverException message

class exceptions.InvalidOperationException(message: str = 'The requested operation cannot be undertaken at this time.')

The client asked for something that can’t be done

Initialize the InvalidOperationException object

Parameters:

  • number (int) – 0x040B (1035)

  • message (str) – ‘The requested operation cannot be undertaken at this time.’

  • Logs InvalidOperationException: {message}

class exceptions.InvalidValueException(message: str = 'Invalid value given.')

A value given is invalid or out of range

Initialize the InvalidValueException object

Parameters:

  • number (int) – 0x401 (1025)

  • message (str) – ‘Invalid value given.’

  • Logs InvalidValueException: {message}

class exceptions.NotConnectedException(message: str = 'The device is not connected.')

The device must be connected and is not at this time

Initialize the NotConnectedException object

Parameters:

  • number (int) – 0x407 (1031)

  • message (str) – ‘The device is not connected.’

  • Logs NotConnectedException: {message}

class exceptions.NotImplementedException(message: str = 'Property or method not implemented.')

The requested property or method is not implemented

Initialize the NotImplementedException object

Parameters:

  • number (int) – 0x400 (1024)

  • message (str) – ‘Property or method not implemented.’

  • Logs NotImplementedException: {message}

class exceptions.OperationCancelledException(message: str = 'In-progress (async) operation was cancelled.')

An (asynchronous) in-progress operation has been cancelled

Initialize the OperationCancelledException object

Parameters:

  • number (int) – 0x400 (1024)

  • message (str) – ‘In-progress (async) operation was cancelled.’

  • Logs OperationCancelledException: {message}

class exceptions.ParkedException(message: str = 'Illegal operation while parked.')

Cannot do this while the device is parked

Initialize the ParkedException object

Parameters:

  • number (int) – 0x408 (1032)

  • message (str) – ‘Illegal operation while parked.’

  • Logs ParkedException: {message}

class exceptions.SlavedException(message: str = 'Illegal operation while slaved.')

Cannot do this while the device is slaved

Initialize the SlavedException object

Parameters:

  • number (int) – 0x409 (1033)

  • message (str) – ‘Illegal operation while slaved.’

  • Logs SlavedException: {message}

class exceptions.Success

Default err input to response classes, indicates success

Initialize the Success object

Parameters:

  • number (int) – 0

  • message (str) –

    ’’

class exceptions.ValueNotSetException(message: str = 'The value has not yet been set.')

The requested vzalue has not yet een set

Initialize the ValueNotSetException object

Parameters:

  • number (int) – 0x402 (1026)

  • message (str) – ‘The value has not yet been set.’

  • Logs ValueNotSetException: {message}