ska_tmc_cspsubarrayleafnode.manager package

Submodules

ska_tmc_cspsubarrayleafnode.manager.component_manager module

Component Manager class for CSP Subarray Leaf Node

class ska_tmc_cspsubarrayleafnode.manager.component_manager.CspSLNComponentManager(*args: Any, **kwargs: Any)

Bases: TmcLeafNodeComponentManager

A component manager for The CSP Subarray Leaf Node component.

It supports:

  • Monitoring its component, e.g. detect that it has been turned off or on

abort(task_callback: ska_tango_base.base.TaskCallbackType) Tuple

Aborting the subarray.

Returns:

a result code and message

assign_resources(argin: str, task_callback: ska_tango_base.base.TaskCallbackType, task_abort_event=None) Tuple[ska_control_model.TaskStatus, str]

Submit the AssignResources command in queue.

Returns:

a result code and message

build_device_attribute_map() Dict[str, List[str]]

Builds a dictionary mapping device names to lists of attributes to be subscribed.

Returns:

A mapping from device names to list of attributes.

Return type:

Dict[str, List[str]]

check_device_responsiveness(device_name: str) bool

This method accepts device_name and provides the responsiveness of the device.

clear_command_id_and_mapping(command_class_id: str) None

Method to clear command mapping and resetting command state.

This method handles the common cleanup logic that should be performed at the end of each command’s update_task_status method, including:

  • Clearing the command mapping for the given command_id

  • Clearing the command_id

  • Clearing the command_in_progress

Parameters:

command_class_id (str) – The command_id to clear from command_mapping

clear_command_mapping(command_class_id: str) None

Clear command mapping for given command id.

Parameters:

command_class_id (str) – command id for which command_mapping needs to be cleared

configure(argin: str, task_callback: ska_tango_base.base.TaskCallbackType, task_abort_event=None) Tuple[ska_control_model.TaskStatus, str]

Submit the Configure command in queue.

Returns:

a result code and message

property csp_subarray_dev_name: str

Property that provides the csp subarray device name.

Returns:

Returns the csp subarray device name

Return type:

str

property delay_model: str

Returns the delayModel attribute.

Returns:

the delayModel

Return type:

str

property delay_model_error: str

Get the last delay model error string.

Returns:

delayModel error.

Return type:

str

property devices: list

Method provides the devices monitored by CSP subarray leaf node.

Returns:

returns list of device information.

Return type:

list

end(task_callback: ska_tango_base.base.TaskCallbackType, task_abort_event=None) Tuple[ska_control_model.TaskStatus, str]

Submit the End command in queue.

Returns:

a result code and message

end_scan(task_callback: ska_tango_base.base.TaskCallbackType, task_abort_event=None) Tuple[ska_control_model.TaskStatus, str]

Submit the EndScan command in queue.

Returns:

a result code and message

get_attribute_dict() dict

Returns the dictionary of attributes

Returns:

Dictionary of attributes to be handled by the EventManager.

get_command_id(unique_id: str)

Retrieve the command ID associated with a given unique identifier.

This method searches through the command mapping dictionary to find and return the command ID that corresponds to the provided unique ID.

Parameters:

unique_id (str) – The unique identifier to search for in the command mapping.

Returns:

The command ID associated with the given unique ID,

or None if not found.

Return type:

str

get_device(device_name: str) Optional[Union[ska_tmc_common.device_info.SubArrayDeviceInfo, ska_tmc_common.device_info.DeviceInfo]]

Return the monitored device info by name.

Parameters:

dev_name – name of the device

Returns:

the monitored device info

Return type:

DeviceInfo

get_obs_state() ska_tango_base.control_model.ObsState

Get Current device obsState

Returns:

Current device obsState

Return type:

ObsState

property health_info: dict

Property that provides the health information of the device.

Returns:

Returns the health information of the device

Return type:

dict

property health_state: ska_control_model.HealthState

Property that provides the health state of the device.

Returns:

Returns the health state of the device

Return type:

HealthState

property input_parameter

Return the input parameter

Returns:

input parameter

Return type:

InputParameter

is_command_allowed(command_name: str) Union[bool, ska_tmc_common.exceptions.InvalidObsStateError, ska_tmc_common.exceptions.DeviceUnresponsive, ska_tmc_common.exceptions.CommandNotAllowed]

Checks whether this command is allowed. It checks that the device is in a state to perform this command and that all the component needed for the operation are not unresponsive.

Parameters:

command_name (str) – name of the command

Returns:

True if this command is allowed

Return type:

boolean

is_command_allowed_callable(command_name: str) bool

Return whether the command may be called in the current state. :param command_name: Name for the command for which the is_allowed :type command_name: str :param check need to be applied.:

Returns:

whether the command may be called in the current device state

Return type:

bool

is_scan_completed()

A function to check whether Scan Command is completed succesfully.

off(task_callback)

Empty method for resolving lint issue

on(task_callback)

Empty method for resolving lint issue

process_event(attribute_name: str) None

Process the given attribute’s event using the data from the event_queues and invoke corresponding process method.

Parameters:

attribute_name (str) – Name of the attribute for which event is to be processed

process_weather_data(event_data: tango.EventData) None

Processing the weather data

raise_invalid_obsstate_error(command_name: str) ska_tmc_common.exceptions.InvalidObsStateError

checking the InvalidObsState of Csp Subarray device

Parameters:

command_name (str) – The name of command

Raises:

InvalidObsStateError – raises along with exception message

register_command_mapping(command_id: str, unique_id: str) None

Set the command mapping for a given command ID and unique identifier.

This method adds an entry to the command mapping dictionary, associating the provided command ID with the unique ID.

Parameters:
  • command_id (str) – The command ID to be mapped.

  • unique_id (str) – The unique identifier to associate with the command ID.

release_all_resources(task_callback: ska_tango_base.base.TaskCallbackType, task_abort_event=None) Tuple[ska_control_model.TaskStatus, str]

Submit the ReleaseAllResources command in queue.

Returns:

a result code and message

restart(task_callback: Optional[Callable] = None, task_abort_event=None) tuple

Submit the Restart command in queue.

Returns:

a result code and message

scan(argin: str, task_callback: ska_tango_base.base.TaskCallbackType, task_abort_event=None) Tuple[ska_control_model.TaskStatus, str]

Submit the Scan command in queue.

Returns:

a result code and message

set_abort_event()

Sets necessary abort events.

set_health_info(health_info: dict) None

Sets the health info of the device.

set_health_state(health_state: ska_control_model.HealthState) None

Sets the health state of the device.

set_target(target) None

Set the target with a KatPoint Target object.

Parameters:

target (katpoint.Target) – A KatPoint Target object representing the pointing target with sky coordinates and other parameters.

setup_event_subscription() None

Sets up the event subscription after input parameters are updated.

standby(task_callback)

Empty method for resolving lint issue

start_communicating()

Empty method for resolving lint issue

stop() None

Stops the event manager

stop_communicating()

Empty method for resolving lint issue

update_device_admin_mode(admin_mode: ska_control_model.AdminMode) None

Update a monitored device admin mode, and call the relative callbacks if available

Parameters:

admin_state – admin mode of the device

update_device_health_state(health_state: ska_control_model.HealthState) None

Update a monitored device health state aggregate the health states available

Parameters:

health_state (HealthState) – health state of the device

update_device_obs_state(obs_state: ska_tango_base.control_model.ObsState) None

Update a monitored device obs state, and call the relative callbacks if available

Parameters:

obs_state (ObsState) – obs state of the device

update_event_failure() None

Update the failure status of an event for a specific device.

update_exception_for_unresponsiveness(device_info: ska_tmc_common.device_info.SubArrayDeviceInfo, exception: str) None

Set a device to failed and call the relative callback if available

Parameters:
  • device_info (DeviceInfo) – a device info

  • exception (Exception) – an exception

update_responsiveness_info(device_name: str) None

Update a device with the correct availability information.

Parameters:

dev_name (str) – name of the device

update_weather_data(key: str, value: dict) None

Called by the Component Manager to push new sensor readings.

Parameters:
  • key (str) – The name of the weather attribute to update

  • value (float) – The new sensor reading for that attribute.

Raises:

KeyError – If key is not a recognized weather attribute.

property weather_data: dict

Read-only access to the current weather data.

Returns:

A mapping of weather attribute names to their current value

Return type:

dict

ska_tmc_cspsubarrayleafnode.manager.event_manager module

Event manager class for CspLeafNode

class ska_tmc_cspsubarrayleafnode.manager.event_manager.CspSLNEventManager(*args: Any, **kwargs: Any)

Bases: EventManager

CspSLNEventManager class inherits from EventManager and adds event callbacks.

adminmode_event_callback(event: tango.EventData) None

It handles the admin mode events of subsystem’s controller and subaray devices.

Parameters:

event_data (tango.EventType.CHANGE_EVENT) – to flag the change in event.

cspcontrolleradminmode_event_callback(event: tango.EventData) None

It handles the adminMode events of csp controller device.

Parameters:

event_data (tango.EventType.CHANGE_EVENT) – to flag the change in event.

cspsubarrayobsstate_event_callback(event: tango.EventData) None

Callback for cspSubarrayObsState attribute.

Delegates to specific handlers based on device type.

Parameters:

event_data (tango.EventType.CHANGE_EVENT) – to flag the change in event.

dishvccconfig_event_callback(event: tango.EventData) None

Handle dishVccConfig change event.

Parameters:

event_data (tango.EventType.CHANGE_EVENT) – to flag the change in event.

healthstate_event_callback(event: tango.EventData) None

It handles the health state events of subsystem’s controller and subarray devices.

Parameters:

event_data (tango.EventType.CHANGE_EVENT) – to flag the change in event.

humidity_event_callback(event: tango.EventData) None

Callback for humidity attribute.

Delegates to specific handlers based on device type.

Parameters:

event_data (tango.EventType.CHANGE_EVENT) – to flag the change in event.

longrunningcommandresult_event_callback(event: tango.EventData) None

Callback for longRunningCommandResult attribute.

Delegates to specific handlers based on device type.

Parameters:

event_data (tango.EventType.CHANGE_EVENT) – to flag the change in event.

obsstate_event_callback(event: tango.EventData) None

Handles observation state event.

Parameters:

event_data (tango.EventType.CHANGE_EVENT) – to flag the change in event.

pressure_event_callback(event: tango.EventData) None

Callback for pressure attribute.

Delegates to specific handlers based on device type.

Parameters:

event_data (tango.EventType.CHANGE_EVENT) – to flag the change in event.

sourcedishvccconfig_event_callback(event: tango.EventData) None

Handle sourceDishVccConfig change event.

Parameters:

event_data (tango.EventType.CHANGE_EVENT) – to flag the change in event.

state_event_callback(event: tango.EventData) None

It handles the state events of subsystem’s controller and subaray devices.

Parameters:

event_data (tango.EventType.CHANGE_EVENT) – to flag the change in event.

temperature_event_callback(event: tango.EventData) None

Callback for temperature attribute.

Delegates to specific handlers based on device type.

Parameters:

event_data (tango.EventType.CHANGE_EVENT) – to flag the change in event.

Module contents

Init file for CSP Subarray Leaf Node Manager

class ska_tmc_cspsubarrayleafnode.manager.CspSLNComponentManager(*args: Any, **kwargs: Any)

Bases: TmcLeafNodeComponentManager

A component manager for The CSP Subarray Leaf Node component.

It supports:

  • Monitoring its component, e.g. detect that it has been turned off or on

abort(task_callback: ska_tango_base.base.TaskCallbackType) Tuple

Aborting the subarray.

Returns:

a result code and message

assign_resources(argin: str, task_callback: ska_tango_base.base.TaskCallbackType, task_abort_event=None) Tuple[ska_control_model.TaskStatus, str]

Submit the AssignResources command in queue.

Returns:

a result code and message

build_device_attribute_map() Dict[str, List[str]]

Builds a dictionary mapping device names to lists of attributes to be subscribed.

Returns:

A mapping from device names to list of attributes.

Return type:

Dict[str, List[str]]

check_device_responsiveness(device_name: str) bool

This method accepts device_name and provides the responsiveness of the device.

clear_command_id_and_mapping(command_class_id: str) None

Method to clear command mapping and resetting command state.

This method handles the common cleanup logic that should be performed at the end of each command’s update_task_status method, including:

  • Clearing the command mapping for the given command_id

  • Clearing the command_id

  • Clearing the command_in_progress

Parameters:

command_class_id (str) – The command_id to clear from command_mapping

clear_command_mapping(command_class_id: str) None

Clear command mapping for given command id.

Parameters:

command_class_id (str) – command id for which command_mapping needs to be cleared

configure(argin: str, task_callback: ska_tango_base.base.TaskCallbackType, task_abort_event=None) Tuple[ska_control_model.TaskStatus, str]

Submit the Configure command in queue.

Returns:

a result code and message

property csp_subarray_dev_name: str

Property that provides the csp subarray device name.

Returns:

Returns the csp subarray device name

Return type:

str

property delay_model: str

Returns the delayModel attribute.

Returns:

the delayModel

Return type:

str

property delay_model_error: str

Get the last delay model error string.

Returns:

delayModel error.

Return type:

str

property devices: list

Method provides the devices monitored by CSP subarray leaf node.

Returns:

returns list of device information.

Return type:

list

end(task_callback: ska_tango_base.base.TaskCallbackType, task_abort_event=None) Tuple[ska_control_model.TaskStatus, str]

Submit the End command in queue.

Returns:

a result code and message

end_scan(task_callback: ska_tango_base.base.TaskCallbackType, task_abort_event=None) Tuple[ska_control_model.TaskStatus, str]

Submit the EndScan command in queue.

Returns:

a result code and message

get_attribute_dict() dict

Returns the dictionary of attributes

Returns:

Dictionary of attributes to be handled by the EventManager.

get_command_id(unique_id: str)

Retrieve the command ID associated with a given unique identifier.

This method searches through the command mapping dictionary to find and return the command ID that corresponds to the provided unique ID.

Parameters:

unique_id (str) – The unique identifier to search for in the command mapping.

Returns:

The command ID associated with the given unique ID,

or None if not found.

Return type:

str

get_device(device_name: str) Optional[Union[ska_tmc_common.device_info.SubArrayDeviceInfo, ska_tmc_common.device_info.DeviceInfo]]

Return the monitored device info by name.

Parameters:

dev_name – name of the device

Returns:

the monitored device info

Return type:

DeviceInfo

get_obs_state() ska_tango_base.control_model.ObsState

Get Current device obsState

Returns:

Current device obsState

Return type:

ObsState

property health_info: dict

Property that provides the health information of the device.

Returns:

Returns the health information of the device

Return type:

dict

property health_state: ska_control_model.HealthState

Property that provides the health state of the device.

Returns:

Returns the health state of the device

Return type:

HealthState

property input_parameter

Return the input parameter

Returns:

input parameter

Return type:

InputParameter

is_command_allowed(command_name: str) Union[bool, ska_tmc_common.exceptions.InvalidObsStateError, ska_tmc_common.exceptions.DeviceUnresponsive, ska_tmc_common.exceptions.CommandNotAllowed]

Checks whether this command is allowed. It checks that the device is in a state to perform this command and that all the component needed for the operation are not unresponsive.

Parameters:

command_name (str) – name of the command

Returns:

True if this command is allowed

Return type:

boolean

is_command_allowed_callable(command_name: str) bool

Return whether the command may be called in the current state. :param command_name: Name for the command for which the is_allowed :type command_name: str :param check need to be applied.:

Returns:

whether the command may be called in the current device state

Return type:

bool

is_scan_completed()

A function to check whether Scan Command is completed succesfully.

off(task_callback)

Empty method for resolving lint issue

on(task_callback)

Empty method for resolving lint issue

process_event(attribute_name: str) None

Process the given attribute’s event using the data from the event_queues and invoke corresponding process method.

Parameters:

attribute_name (str) – Name of the attribute for which event is to be processed

process_weather_data(event_data: tango.EventData) None

Processing the weather data

raise_invalid_obsstate_error(command_name: str) ska_tmc_common.exceptions.InvalidObsStateError

checking the InvalidObsState of Csp Subarray device

Parameters:

command_name (str) – The name of command

Raises:

InvalidObsStateError – raises along with exception message

register_command_mapping(command_id: str, unique_id: str) None

Set the command mapping for a given command ID and unique identifier.

This method adds an entry to the command mapping dictionary, associating the provided command ID with the unique ID.

Parameters:
  • command_id (str) – The command ID to be mapped.

  • unique_id (str) – The unique identifier to associate with the command ID.

release_all_resources(task_callback: ska_tango_base.base.TaskCallbackType, task_abort_event=None) Tuple[ska_control_model.TaskStatus, str]

Submit the ReleaseAllResources command in queue.

Returns:

a result code and message

restart(task_callback: Optional[Callable] = None, task_abort_event=None) tuple

Submit the Restart command in queue.

Returns:

a result code and message

scan(argin: str, task_callback: ska_tango_base.base.TaskCallbackType, task_abort_event=None) Tuple[ska_control_model.TaskStatus, str]

Submit the Scan command in queue.

Returns:

a result code and message

set_abort_event()

Sets necessary abort events.

set_health_info(health_info: dict) None

Sets the health info of the device.

set_health_state(health_state: ska_control_model.HealthState) None

Sets the health state of the device.

set_target(target) None

Set the target with a KatPoint Target object.

Parameters:

target (katpoint.Target) – A KatPoint Target object representing the pointing target with sky coordinates and other parameters.

setup_event_subscription() None

Sets up the event subscription after input parameters are updated.

standby(task_callback)

Empty method for resolving lint issue

start_communicating()

Empty method for resolving lint issue

stop() None

Stops the event manager

stop_communicating()

Empty method for resolving lint issue

update_device_admin_mode(admin_mode: ska_control_model.AdminMode) None

Update a monitored device admin mode, and call the relative callbacks if available

Parameters:

admin_state – admin mode of the device

update_device_health_state(health_state: ska_control_model.HealthState) None

Update a monitored device health state aggregate the health states available

Parameters:

health_state (HealthState) – health state of the device

update_device_obs_state(obs_state: ska_tango_base.control_model.ObsState) None

Update a monitored device obs state, and call the relative callbacks if available

Parameters:

obs_state (ObsState) – obs state of the device

update_event_failure() None

Update the failure status of an event for a specific device.

update_exception_for_unresponsiveness(device_info: ska_tmc_common.device_info.SubArrayDeviceInfo, exception: str) None

Set a device to failed and call the relative callback if available

Parameters:
  • device_info (DeviceInfo) – a device info

  • exception (Exception) – an exception

update_responsiveness_info(device_name: str) None

Update a device with the correct availability information.

Parameters:

dev_name (str) – name of the device

update_weather_data(key: str, value: dict) None

Called by the Component Manager to push new sensor readings.

Parameters:
  • key (str) – The name of the weather attribute to update

  • value (float) – The new sensor reading for that attribute.

Raises:

KeyError – If key is not a recognized weather attribute.

property weather_data: dict

Read-only access to the current weather data.

Returns:

A mapping of weather attribute names to their current value

Return type:

dict

class ska_tmc_cspsubarrayleafnode.manager.CspSLNComponentManagerLow(*args: Any, **kwargs: Any)

Bases: CspSLNComponentManager

A component manager for The CSP Subarray Leaf Node Low component.

property delay_model_pst_beam1: str

Returns the delayModelPSTBeam attribute.

Returns:

the delayModelPSTBeam

Return type:

str

property delay_model_pst_beam2: str

Returns the delayModelPSTBeam attribute.

Returns:

the delayModelPSTBeam

Return type:

str

property delay_model_station_beam_01: str

Get the delay model value for station beam 01.

Returns:

JSON string representing the delay model for beam 01.

Return type:

str

property delay_model_station_beam_02: str

Get the delay model value for station beam 02.

Returns:

JSON string representing the delay model for beam 02.

Return type:

str

property delay_model_station_beam_03: str

Get the delay model value for station beam 03.

Returns:

JSON string representing the delay model for beam 03.

Return type:

str

property delay_model_station_beam_04: str

Get the delay model value for station beam 04.

Returns:

JSON string representing the delay model for beam 04.

Return type:

str

property delay_model_station_beam_05: str

Get the delay model value for station beam 05.

Returns:

JSON string representing the delay model for beam 05.

Return type:

str

property delay_model_station_beam_06: str

Get the delay model value for station beam 06.

Returns:

JSON string representing the delay model for beam 06.

Return type:

str

property delay_model_station_beam_07: str

Get the delay model value for station beam 07.

Returns:

JSON string representing the delay model for beam 07.

Return type:

str

property delay_model_station_beam_08: str

Get the delay model value for station beam 08.

Returns:

JSON string representing the delay model for beam 08.

Return type:

str

get_pss_beam_tango_attributes() list[str]

Function to fetch pss beam tango attrs from Component Manager obj

Returns:

list of pss beam tango attributes

Return type:

list[str]

get_pst_beam_tango_attributes() list[str]

Function to fetch pst beam tango attrs from Component Manager obj

Returns:

list of pst beam tango attributes

Return type:

list[str]

get_station_ids() list

Returns the station IDs received under lowcbf configurations.

Returns:

station IDs

Return type:

list

get_station_substation_ids() list[list[Any]]

Returns the stations and sub-stations IDs received under lowcbf configurations.

Returns:

station and sub-station IDs

Return type:

list[list]

get_stn_beam_tango_attributes() list[str]

Function to fetch station beam tango attrs from Component Manager obj

Returns:

list of pst beam tango attributes

Return type:

list[str]

set_beam_target(beam_id: int, target_object) None

Set the target for a specific beam using a KatPoint Target object.

Parameters:
  • beam_id (int) – ID of the beam to set the target for.

  • target_object – KatPoint Target object representing the beam’s target.

Example:

set_beam_target(1, katpoint.Target("azel, 30, 45, target1"))
update_delay_model_for_station_beam(beam_id: str, model: str) None

Update delay model value for a specific station beam.

Parameters:
  • beam_id (str) – Beam ID as a string (e.g., “1”, “2”, “3”, “4”).

  • model (str) – JSON string representing the delay model.

class ska_tmc_cspsubarrayleafnode.manager.CspSLNComponentManagerMid(*args: Any, **kwargs: Any)

Bases: CspSLNComponentManager

A component manager for The CSP Subarray Leaf Node Mid component.

get_receptor_ids()

Returns the receptor IDs.

Returns:

receptor IDs

Return type:

list

class ska_tmc_cspsubarrayleafnode.manager.CspSLNEventManager(*args: Any, **kwargs: Any)

Bases: EventManager

CspSLNEventManager class inherits from EventManager and adds event callbacks.

adminmode_event_callback(event: tango.EventData) None

It handles the admin mode events of subsystem’s controller and subaray devices.

Parameters:

event_data (tango.EventType.CHANGE_EVENT) – to flag the change in event.

cspcontrolleradminmode_event_callback(event: tango.EventData) None

It handles the adminMode events of csp controller device.

Parameters:

event_data (tango.EventType.CHANGE_EVENT) – to flag the change in event.

cspsubarrayobsstate_event_callback(event: tango.EventData) None

Callback for cspSubarrayObsState attribute.

Delegates to specific handlers based on device type.

Parameters:

event_data (tango.EventType.CHANGE_EVENT) – to flag the change in event.

dishvccconfig_event_callback(event: tango.EventData) None

Handle dishVccConfig change event.

Parameters:

event_data (tango.EventType.CHANGE_EVENT) – to flag the change in event.

healthstate_event_callback(event: tango.EventData) None

It handles the health state events of subsystem’s controller and subarray devices.

Parameters:

event_data (tango.EventType.CHANGE_EVENT) – to flag the change in event.

humidity_event_callback(event: tango.EventData) None

Callback for humidity attribute.

Delegates to specific handlers based on device type.

Parameters:

event_data (tango.EventType.CHANGE_EVENT) – to flag the change in event.

longrunningcommandresult_event_callback(event: tango.EventData) None

Callback for longRunningCommandResult attribute.

Delegates to specific handlers based on device type.

Parameters:

event_data (tango.EventType.CHANGE_EVENT) – to flag the change in event.

obsstate_event_callback(event: tango.EventData) None

Handles observation state event.

Parameters:

event_data (tango.EventType.CHANGE_EVENT) – to flag the change in event.

pressure_event_callback(event: tango.EventData) None

Callback for pressure attribute.

Delegates to specific handlers based on device type.

Parameters:

event_data (tango.EventType.CHANGE_EVENT) – to flag the change in event.

sourcedishvccconfig_event_callback(event: tango.EventData) None

Handle sourceDishVccConfig change event.

Parameters:

event_data (tango.EventType.CHANGE_EVENT) – to flag the change in event.

state_event_callback(event: tango.EventData) None

It handles the state events of subsystem’s controller and subaray devices.

Parameters:

event_data (tango.EventType.CHANGE_EVENT) – to flag the change in event.

temperature_event_callback(event: tango.EventData) None

Callback for temperature attribute.

Delegates to specific handlers based on device type.

Parameters:

event_data (tango.EventType.CHANGE_EVENT) – to flag the change in event.