Telemetry#

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

Bases: BaseRule

Monitor the presence of telemetry from a SAL component.

Set alarm severity NONE whenever telemetry arrives and the configured level if the telemetry does not arrive in time.

Parameters:

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

Notes

The alarm name is f”Telemetry.{name}:{index}”, where name and index are derived from config.name. The alarm severity is configurable as well as the amount of time after which the alarm will be raised.

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.
`restart_timer`()	Start or restart the telemetry timer.
`start`()	Start any background tasks, such as a polling loop.
`stop`()	Stop all background tasks.
`stop_timer`()
`telemetry_timer`()	telemetry timer.

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.

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)

restart_timer()#: Start or restart the telemetry 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().

stop_timer()#

async telemetry_timer()#: telemetry timer.