VILLASnode/include/villas/nodes/signal.hpp

/** Node-type for signal generation.
 *
 * @file
 * @author Steffen Vogel <post@steffenvogel.de>
 * @copyright 2014-2022, Institute for Automation of Complex Power Systems, EONERC
 * @license Apache 2.0
 *********************************************************************************/

#pragma once

#include <villas/timing.hpp>
#include <villas/task.hpp>
#include <villas/node.hpp>

namespace villas {
namespace node {

/* Forward declarations */
struct Sample;

class SignalNodeSignal {

public:
	enum class Type {
		RANDOM,
		SINE,
		SQUARE,
		TRIANGLE,
		RAMP,
		COUNTER,
		CONSTANT,
		PULSE,
		MIXED
	};

	enum Type type;

	double frequency;		/**< Frequency of the generated signals. */
	double amplitude;		/**< Amplitude of the generated signals. */
	double stddev;			/**< Standard deviation of random signals (normal distributed). */
	double offset;			/**< A constant bias. */
	double pulse_width;		/**< Width of a pulse with respect to the rate (duration = pulse_width/rate) */
	double pulse_low;		/**< Amplitude when pulse signal is off */
	double pulse_high;		/**< Amplitude when pulse signal is on */
	double phase;			/**< Phase (rad) offset with respect to program start */
	double last;			/**< The values from the previous period which are required for random walk. */

public:
	SignalNodeSignal(json_t *json);

	int parse(json_t *json);

	static
	enum Type lookupType(const std::string &type);

	static
	std::string typeToString(enum Type type);

	void start();

	void read(unsigned c, double t, double rate, SignalData *d);

	Signal::Ptr toSignal(Signal::Ptr tpl) const;
};

class SignalNode : public Node {

protected:
	std::vector<SignalNodeSignal> signals;

	struct Task task;			/**< Timer for periodic events. */
	int rt;					/**< Real-time mode? */

	double rate;				/**< Sampling rate. */
	bool monitor_missed;			/**< Boolean, if set, node counts missed steps and warns user. */
	int limit;				/**< The number of values which should be generated by this node. <0 for infinite. */

	struct timespec started;		/**< Point in time when this node was started. */
	unsigned missed_steps;			/**< Total number of missed steps. */

	virtual
	int _read(struct Sample *smps[], unsigned cnt);

public:
	SignalNode(const uuid_t &id = {}, const std::string &name = "");

	virtual
	const std::string & getDetails();

	virtual
	int parse(json_t *json);

	virtual
	int start();

	virtual
	int stop();

	virtual
	int prepare();

	virtual
	std::vector<int> getPollFDs();
};

} // namespace node
} // namespace villas