ATCameraDewar#

class lsst.ts.watcher.rules.ATCameraDewar(config, log=None)#

Bases: BaseRule

Monitor ATCamera dewar temperatures and vacuum.

Parameters:

config (types.SimpleNamespace) – Rule configuration, as validated by the schema.
log (logging.Logger, optional) – Parent logger.

Raises:

jsonschema.ValidationError – If the configuration does not match the schema.
ValueError – If the three threshold levels for a given measurement, e.g. the three min_*_ccd_temp fields, are all null or absent. If you want to suppress all alarms for a measurement, specify an unrealistic value for at least one threshold level for that measurement.

Notes

The alarm name is “ATCameraDewar”.

The rule raises an alarm if any of the following are true:

ccd temperature is too low
ccd temperature is too high
cold plate temperature is too high
cryo head temperature is too high
vacuum is too soft (pressure is too high)

You may configure up to three severity threshold levels for each of these alarm conditions, but typically you should only specify two: a warning level and either a serious or a critical level.

The vacuum pressure gauge occasionally “burps”, and temperature measurements fluctuate somewhat, so alarm thresholds are based on median values reported within a configurable time window.

Methods Summary

`compute_alarm_severity`(data, **kwargs)	Compute and set alarm severity and reason.
`get_schema`()	Return a jsonschema as a `dict`, to validate configuration.
`no_data_timer`()	Timer for no data received.
`reset_all`()	Reset the alarm, clear the data queue, and restart the no-data timer.
`restart_no_data_timer`()	Start or restart the no-data timer.
`start`()	Start any background tasks, such as a polling loop.
`stop`()	Stop all background tasks.

Methods Documentation

compute_alarm_severity(data, **kwargs)#

Compute and set alarm severity and reason.

Parameters:

**kwargs (dict [str, typing.Any]) –

Keyword arguments. If triggered by TopicCallback calling update_alarm_severity, the arguments will be as follows:

data : salobj.BaseMsgType Message from the topic described by topic_callback.
topic_callback : TopicCallback Topic callback wrapper.

Return type:

tuple[AlarmSeverity, str] | None

Returns:

None, if no change or unknown, or a tuple of two values
severity (lsst.ts.xml.enums.Watcher.AlarmSeverity) – The new alarm severity.
reason (str) – Detailed reason for the severity, e.g. a string describing what value is out of range, and what the range is. If severity is NONE then this value is ignored (but still required) and the old reason is retained until the alarm is reset to nominal state.

Notes

You may return NoneNoReason if the alarm state is NONE.

Parameters:: data (BaseMsgType)

classmethod get_schema()#

Return a jsonschema as a dict, to validate configuration.

Return type:: Dict[str, Any]

Notes

Please provide default values for all fields for which defaults make sense. This makes watcher configuration files easier to write.

If your rule has no configuration then return None.

We recommend that you write the schema as yaml, for compactness, then use yaml.safe_load to convert it to a dict. For example:

schema_yaml = """
    $schema: http://json-schema.org/draft-07/schema#
    description: Configuration for MyRule
    type: object
    properties:
    ...
    required: [...]
    additionalProperties: false
"""
return yaml.safe_load(schema_yaml)

async no_data_timer()#: Timer for no data received.

reset_all()#: Reset the alarm, clear the data queue, and restart the no-data timer.

restart_no_data_timer()#: Start or restart the no-data timer.

start()#

Start any background tasks, such as a polling loop.

This is called when the watcher goes into the enabled state.

Notes

Do not assume that start is called before stop; the order depends on the initial state of the Watcher.

Immediate subclasses need not call super().start()

stop()#

Stop all background tasks.

This is called when the watcher goes out of the enabled state, and must stop any tasks that might trigger an alarm state change.

Notes

Do not assume that start is called before stop; the order depends on the initial state of the Watcher.

This base implementation does nothing, so immediate subclasses need not call super().stop().