cern.cmw.rda.examples
Class NoiseGenerator

java.lang.Object
  cern.cmw.rda.examples.NoiseGenerator

public class NoiseGenerator
extends Object

A device simulator that allows to check all basic device access methods.

A NoiseGenerator device has two properties:

• AQN - a simulated asquisition property. The property value fluctuates randomly around the baseline defined by the CCV property.
  • Type: double
  • Range: 0.0 ... 100.0
  • Access: read-only
• CCV - a control property that defines a baseline for the AQN property.
  • Type: double
  • Access: read-write
  • Range: 0.0 ... 100.0
  • Access: read-write
  • Default: 50.0

Applications can read and monitor values of all properties, and change the CCV value. The cycleSelector and context parameters are ignored in all access methods.

Method Summary

Data	get(IOPoint iop, Data context) Returns a value of the specified property in a Data object.
void	monitorOff(IOPoint iop, ValueChangeListener listener) Detaches the specified listener from the specified property.
void	monitorOn(IOPoint iop, ValueChangeListener listener) Attaches the specified listener to the specified property.
void	set(IOPoint iop, Data value, Data context) Sets the specified property to the specified value.
void	update() Updates the AQN value and notifies attached listeners, if any.

Methods inherited from class java.lang.Object

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

Method Detail

update

public void update()

Updates the AQN value and notifies attached listeners, if any.

In a real device this method would perform physical I/O; here it adds a random value within the -5.0 ... 5.0 range to the current CCV value, then informs all attached listeners on the value update. The on-change monitors will be fired if difference between new and old values is more then 1.0. The reported Data contains "value" and "timestamp" entries. If the AQN value occasionally goes out of its legal range then a simulated IOError will be reported.

get

public Data get(IOPoint iop,
                Data context)
         throws BadParameter,
                IOError

Returns a value of the specified property in a Data object. For AQN, the result Data contains two entries:

• "value" - current property value
• "timestamp" - time when the value was last updated (double, msec since midnight, January 1, 1970 UTC)

For CCV, it only contains the "value" entry.

Throws:

BadParameter - if there is no such property in the device

IOError - if an I/O error has been detected in the last update cycle (AQN only)

See Also:

update()

set

public void set(IOPoint iop,
                Data value,
                Data context)
         throws BadParameter,
                IOError

Sets the specified property to the specified value. The new value is expected in the data entry tagged "value". If the operation does not result in an exception then all listeners attached to the property will be notified on the value change.

Throws:

BadParameter - if there is no such property in the device, or if the value Data does not contain the "value" entry, or if the value contained is not a double, or if the new value is out of the legal CCV range.

IOError - if the specified property is AQN (no write access)

monitorOn

public void monitorOn(IOPoint iop,
                      ValueChangeListener listener)
               throws BadParameter

Attaches the specified listener to the specified property.

Throws:

BadParameter - if there is no such property in the device

monitorOff

public void monitorOff(IOPoint iop,
                       ValueChangeListener listener)

Detaches the specified listener from the specified property.