Package org.lsst.ccs.subsystem.airwatch.main

The main package for the AirWatch subsystem.

See: Description

Interface Summary

Interface	Description
Instrument	Represents a particle-counting instrument.
LocalConfigService	Represents a repository of configuration information.
TrendableRecord	Defines the interface to trendable data from an instrument.

Class Summary

Class	Description
AirwatchMain	The main module for the Airwatch subsystem.
Alerts	Contains a set of static factory functions for the alerts used by the subsystem.
CCSConfiguration	Implements a local configuration service based on the CCS subsystem configuration and persistence APIs.
DummyInstrument	A dummy instrument used to test the subsystem.
EmailSender	Sends email messages using some simple scheduling in order to avoid spamming.
InstrumentConfig	The configuration information maintained for each instrument.
InstrumentReport	A snapshot of the status of all instruments.
InstrumentStatus
LighthouseModbus	Implements readout of a Lighthouse Worldwide Solutions 3016-like instrument with a direct serial or network connection.
LighthouseOPC	Copies instrument readings published by Lighthouse's LMS Express RT program.
LighthouseOPC.AnalogPoint
LighthouseOPC.CounterPoint
LocationConfig	Holds configuration information about a location.
TrendableModbusRecord	Describes an immutable data record matching a record gotten from a directly-connected Lighthouse instrument.
TrendableOPCRecord	Implements a trendable data item read from a Lighthouse OPC server.

Enum Summary

Enum	Description
InstrumentChannel	The quantities that may be monitored by each instrument.
InstrumentType	The different kinds of instruments recognized by the subsystem.

Package org.lsst.ccs.subsystem.airwatch.main Description

The main package for the AirWatch subsystem.

At subsystem start-up a periodic task is started to read the particle-counter instruments with at regular intervals (fixed period) and send the data to the trending subsystem. Only new data, accumulated since the last time data was read, is posted for each instrument.

A stop command will have no effect on a readout in progress but will cancel any further readouts.

An abort command will interrupt a readout in progress. Subsequent readouts will still occur if they are scheduled. An abort is a no-op if no readout is in progress. When a readout is interrupted a given instrument will either have had its new data sent to trending and its last-data-time updated, or neither.

Query commands will execute without delay, though they might not show concurrent changes in instrument state being made by action commands or the readout task.

Action commands that mutate instrument state will be rejected if a readout is in progress, otherwise they'll run without delay. Readout may take several minutes so it seems better to reject conflicting commands right away so that the operators can abort the current readout if they want.

If the readout task encounters an instrument I/O error it will raise an alert of severity WARNING whose ID is "InstrumentIO". The cause string will be the instrument location plus the message from the HardwareException that was thrown as a result of the problem. Operators may wish to abort and disable readout for the offending channel. Before clearing the alert the operators may attempt to re-enable the instrument or decide to leave it disabled. In either case the alert may be cleared without further checks by the subsystem.

Lighthouse instruments

The instrument contains a table of location names which should be the same as the list of known locations obtained from the subsystem configuration. That way changing the instrument's current location can be done just by writing the index number + 1 to the current-location register.

Those Lighthouse hand-held models allow only uppercase letters to be entered for location names, so case is ignored when comparing the names with configured location names for all models.

The enable and read operations sync a hand-held instrument's clock with that of the computer.