ConstantDriftOscillator

simple module

Oscillator with constant fractional frequency offset (drift).

Summary

Produces a strictly periodic tick sequence whose rate is a constant factor faster or slower than the nominal tick length. No per-tick events are scheduled; mappings follow ~IOscillator semantics via the base.

Semantics

Let L be the nominal tick length and r be driftRate in ppm.
Effective factor d = 1 + r·1e−6.
Current tick length: L_current = L / d. * r > 0 → faster oscillator (shorter ticks) * r = 0 → nominal rate * r < 0 → slower oscillator (longer ticks)

Inheritance diagram

The following diagram shows inheritance relationships for this type. Unresolved types are missing from the diagram.

Extends

Name	Type	Description
DriftingOscillatorBase	simple module	Base module for oscillators whose effective tick rate may drift relative to a nominal tick length. This module provides the mapping used by clocks without generating one event per tick.

Parameters

Name	Type	Default value	Description
displayStringTextFormat	string	"%c (%n + %d)"	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
emitNumTicksSignal	bool	false	Enables emitting a signal at each oscillator tick, can be useful for validating the behavior of the more efficient implementation without events
oscillatorTickEventSchedulingPriority	int	0	Specifies the scheduling priority of the tick event
nominalTickLength	double		Specifies the elapsed time between oscillator ticks
tickOffset	double	0s	Shifts ticks to the past, must be in the range of [0, current tick length)
driftRate	double	0ppm	Constant fractional frequency offset

Properties

Name	Value	Description
class	ConstantDriftOscillator
display	i=block/tunnel

Signals

Name	Type	Unit	Description
postOscillatorStateChanged
preOscillatorStateChanged

Statistics

Name	Title	Source	Record	Unit	Interpolation Mode	Description
numTicksChanged	number of ticks		vector		sample-hold
driftRateChanged	Oscillator drift rate		vector	ppm	sample-hold

Source code

//
// Oscillator with constant fractional frequency offset (drift).
//
// Summary
// -------
// Produces a strictly periodic tick sequence whose rate is a constant factor
// faster or slower than the nominal tick length. No per-tick events are
// scheduled; mappings follow ~IOscillator semantics via the base.
//
// Semantics
// ---------
// - Let L be the nominal tick length and r be `driftRate` in ppm.
// - Effective factor d = 1 + r·1e−6.
// - Current tick length: L_current = L / d.
//   * r > 0  → faster oscillator (shorter ticks)
//   * r = 0  → nominal rate
//   * r < 0  → slower oscillator (longer ticks)
//
//
simple ConstantDriftOscillator extends DriftingOscillatorBase like IOscillator
{
    parameters:
        double driftRate @unit(ppm) = default(0ppm); // Constant fractional frequency offset
        @class(ConstantDriftOscillator);
}

File: src/inet/clock/oscillator/ConstantDriftOscillator.ned