Message Passing

Detailed Description

Systems for publishing/subscribing to popular message passing ecosystems.

Classes
class	LcmInterfaceSystem
	LcmInterfaceSystem acts within a Diagram to allow LcmSubscriberSystem instances to receive data from the network during a simulation. More...
class	LcmPublisherSystem
	Publishes an LCM message containing information from its input port. More...
class	LcmScopeSystem
	LcmScopeSystem provides the ability to convert any vector output port to a simple LCM message and publish that message periodically. More...
class	LcmSubscriberSystem
	Receives LCM messages from a given channel and outputs them to a System<double>'s port. More...

Functions
LcmPublisherSystem *	ConnectLcmScope (const OutputPort< double > &src, const std::string &channel, systems::DiagramBuilder< double > *builder, drake::lcm::DrakeLcmInterface *lcm, double publish_period=0.0)
	(To be deprecated.) Prefer to use LcmScopeSystem::AddToBuilder instead of this function; the LcmScopeSystem provides more detailed timestamps. More...

Function Documentation

ConnectLcmScope()

LcmPublisherSystem* drake::systems::lcm::ConnectLcmScope	(	const OutputPort< double > &	src,
		const std::string &	channel,
		systems::DiagramBuilder< double > *	builder,
		drake::lcm::DrakeLcmInterface *	lcm,
		double	publish_period = 0.0
	)

(To be deprecated.) Prefer to use LcmScopeSystem::AddToBuilder instead of this function; the LcmScopeSystem provides more detailed timestamps.

Provides the ability to publish any vector-valued output port to the LCM channel, using the drake::lcmt_drake_signal LCM message type, by adding an appropriate LcmPublisherSystem to the builder. If lcm is null, then an LCM instance will be created automatically (but this is expensive, and creating multiple LCM instances in a single process should be avoided).

The intention is to enable logging and debugging in complex diagrams using external tools like lcm-spy.

The optional publish_period specifies how often messages will be published. If the period is zero (the default), then the underlying LcmPublisherSystem will publish every step.

Precondition

src must be an OutputPort of a system that has already been added to the builder.