org.lsst.ccs.subsystem.airwatch.main

Class LighthouseOPC

java.lang.Object

org.lsst.ccs.subsystem.airwatch.main.LighthouseOPC

All Implemented Interfaces:

Instrument

public class LighthouseOPC
extends Object
implements Instrument

Represents an instrument connected to PC running Lighthouse's LMS Express RT program. That program implements an OPC DA server holding only the latest readings from each instrument connected to LMS Express RT.

Each instrument is a cluster of several sensors: two particle counters (for different-sized particles), an ambient relative humidity sensor and an ambient temperature sensor. Each sensor is represented in the instrument by its own "channel". The PC periodically directs each instrument to take sensor readings. Each channel produces several values which are then published by the PC using the OPC DA protocol. Due to the way the protocol works each value is published with its own timestamp even though all the values for a given channel are produced at the same time.

Each counter channel produces an absolute particle count for the air sample, a particle density, a flag indicating a limit violation (out of bounds value) and a sensor malfunction flag. Each analog channel produces a single value together with limit violation and malfunction flags.

Reading the latest OPC DA values using this class produces series of "trendable records". One trendable record is produced per channel. Each has a master key which is the short name for the instrument's location and a master timestamp which is the OPC DA timestamp of one of the channel's values. The trendable record carries the sensor values as a single "item" with a key which is the channel name and a serializable object which is an instance of either AnalogPoint or CounterPoint depending on the type of channel. For counter channels the name is the particle size in microns, e.g., "3.0", "0.3". Temperature channels are named "temp" and humidity channels "humid".

A trendable record record is published on the CCS data bus as a KeyValueDataList (KVD list) whose master timestamp and key are those of the record. Each KVD list has a single member derived from the key and value of the single item in each trendable record. Therefore the trending path to each value is composed of the agent name, the short sensor name, the channel name and the name of the field from the AnalogPoint or CounterPoint object. For example ir2-airwatch/MAIN_NW/3.0/density. Each published KVDL list looks like this:

• Master key = short location name
• Master timestamp
• Item list
  • Item key = channel name, value = instance of AnalogPoint or CounterPoint

Author:

tether

See Also:

AnalogPoint, CounterPoint, TrendableOPCRecord

Constructor Summary

Constructors

Constructor and Description
LighthouseOPC(InstrumentConfig iconf) Constructs a new instance from configuration data.

Method Summary

Modifier and Type	Method and Description
Instrument	disable() Produces a new instance that has readout disabled.
Instrument	enable() Produces a new instance that has been enabled for readout and is serving a new location.
int	getIndex() Gets the position of this instrument in the list of instruments.
Optional<org.lsst.ccs.HardwareException>	getLastException() Gets the exception thrown (if any) the last time we tried to operate on this instrument.
InstrumentStatus	getStatus() Gets the current status of the instrument.
Stream<TrendableRecord>	getTrendables() Gets all the trendable data resulting from the last reading of the instrument.
Instrument	read() Produces a new instance that contains a fresh set of data read from the instrument.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

LighthouseOPC

public LighthouseOPC(InstrumentConfig iconf)

Constructs a new instance from configuration data. The new instance will have no stored data and have no stored exception.

Parameters:

iconf - The subsystem's configuration information for the instrument.

Method Detail

getLastException

public Optional<org.lsst.ccs.HardwareException> getLastException()

Gets the exception thrown (if any) the last time we tried to operate on this instrument.

Specified by:

getLastException in interface Instrument

Returns:

An empty Optional if there have been no operations or if the last operation was successful. Otherwise an Optional containing the exception that terminated the operation. Getters are not considered operations.

getIndex

public int getIndex()

Gets the position of this instrument in the list of instruments.

Specified by:

getIndex in interface Instrument

Returns:

The index.

See Also:

LocalConfigService.getInstrumentConfigs()

getStatus

public InstrumentStatus getStatus()

Gets the current status of the instrument. This method will be used in QUERY-type commands, so implementations must rely solely on data in memory and must not perform any hardware operations.

Specified by:

getStatus in interface Instrument

Returns:

The status object.

getTrendables

public Stream<TrendableRecord> getTrendables()

Gets all the trendable data resulting from the last reading of the instrument.

Specified by:

getTrendables in interface Instrument

Returns:

A stream of TrendableRecord instances, empty if no data is available, for example if the instrument has never been read or if the last read found no new data or failed. The master key of each record is the location for which the data were taken. The master timestamp is the time at which the record was made. Each key/value pair consists of a channel name and value.

See Also:

Instrument.read()

disable

public Instrument disable()

Produces a new instance that has readout disabled.

Specified by:

disable in interface Instrument

Returns:

The new instance.

enable

public Instrument enable()

Produces a new instance that has been enabled for readout and is serving a new location. The device will be reconfigured for the new location. For example, alarm thresholds will be altered.

Specified by:

enable in interface Instrument

Returns:

The new instance.

read

public Instrument read()

Produces a new instance that contains a fresh set of data read from the instrument. The Instrument.getTrendables() method relies on this data to produce its result.

Specified by:

read in interface Instrument

Returns:

The new instance.