Communications Blocks

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The communications blocks provide a generic set of blocks which may be used with any of the QUARC communications protocols. The communication protocol and protocol parameters are specified with a Universal Resource Identifier or URI. Refer to QUARC Communications Protocols for a discussion of the different communications protocols available.

For using the QUARC communications protocols and other features in external applications, such as C/C++, .NET, or Java refer to the QUARC External Interfaces documentation.

For performing communications from a MATLAB script, refer to the QUARC MATLAB functions for communications.

Basic Communications Blocks

The basic communication blocks are the easiest to use but do not provide the full flexibility of the QUARC communications architecture. However, for most applications they are more than adequate and greatly simplify communications.

Stream Client	Connects to a remote host and sends and/or receives data from that host.
Stream Server	Listens for and accepts a connection from a remote host and sends and/or receives data from that host.
Stream State Constant	Outputs the value of a persistent stream state.
Stream State Comparison	Compares a signal to a persistent stream state.

Intermediate Communications Blocks

The intermediate communication blocks are more advanced than the basic blocks and provide more flexibility. They are intended to be used in the main diagram. Therefore, they only support non-blocking mode for communications where the blocks always return immediately.

Stream Call	Connects to a remote host.
Stream Answer	Listens for and accepts a connection from a remote host.
Stream Write	Sends data over a stream.
Stream Read	Receives data over a stream.
Stream Formatted Write	Sends formatted text over a stream.
Stream Formatted Read	Scans formatted data received over a stream.
Stream Write-Read	Sends and receives data atomically over a stream. This block is intended for use in the main diagram.
Stream Answer State Constant	Outputs the value of a particular Stream Answer block connection state.
Stream Answer State Comparison	Compares the connection state of a Stream Answer block to a particular state.
Stream Call State Constant	Outputs the value of a particular Stream Call block connection state.
Stream Call State Comparison	Compares the connection state of a Stream Call block to a particular state.

Advanced Communications Blocks

The advanced communication blocks provide the full flexibility of the QUARC communications framework but are lower-level blocks that require a more sophisticated knowledge of communications to be used. The advanced blocks support two modes: blocking and non-blocking.

In blocking mode, the blocks do not return until the operation requested is complete. As such, blocking mode is typically used in an asynchronous thread running at a lower priority so that the blocking I/O does not interfere with the sample time performance of the main diagram.

In non-blocking mode, the blocks always return immediately and may therefore be used in the main diagram without compromising sample time performance. However, a simple state machine is generally required to keep track of when a connection is established and data may be transmitted or received.

Invalid Stream	Outputs an invalid stream.
Stream Accept	Accepts a connection from a remote host.
Stream Close	Closes a stream.
Stream Connect	Connects to a remote host.
Stream Flush	Flushes data from the stream buffer to the underlying communication channel.
Stream Listen	Creates a stream that listens for connections from remote hosts.
Stream Poll	Polls for events associated with the stream.
Stream Print	Prints formatted data over a stream.
Stream Receive	Receives data over a stream.
Stream Scan	Scans formatted data received over a stream.
Stream Send	Sends data over a stream.
Stream Get Property	Gets the values of stream properties.
Stream Set Property	Sets the values of stream properties.

Mavlink Communication Blocks

The Mavlink block set is designed to enable QUARC Simulink models to communicate with auto-pilots using the Mavlink protocol.

Mavlink Enumeration	Outputs the value of a Mavlink enumeration constant.
Mavlink Initialize	Establishes connections to Mavlink-based flight controllers.
Mavlink Receive	Receives data over a Mavlink connection.
Mavlink Send	Sends data over a Mavlink connection.

Multiwii Communication Blocks

The Multiwii block set is designed to enable QUARC Simulink models to communicate with auto-pilots using the Multiwii Serial protocol (MSP).

Multiwii Altitude	Reads the altitude of the aircraft.
Multiwii Analog	Reads the analog sensors, such as voltages and currents.
Multiwii Attitude	Reads the attitude of the aircraft.
Multiwii Bind	Binds to satellites.
Multiwii Box Identifiers	Gets the box identifiers used by the auto-pilot.
Multiwii Calibration	Calibrates auto-pilot sensors.
Multiwii Computed GPS	Gets the GPS coordinates relative to the home location.
Multiwii Connect	Connects to an auto-pilot. This block is intended for use in the main diagram.
Multiwii Debug	Gets debug values from the auto-pilot.
Multiwii EEPROM Write	Writes the settings to the auto-pilot EEPROM.
Multiwii Heading Lock	Sets a new heading lock reference.
Multiwii Identity	Gets information about the auto-pilot.
Multiwii IMU	Gets raw IMU sensor data from the auto-pilot.
Multiwii Motor Pins	Gets the motor pin indications from the auto-pilot.
Multiwii Names	Gets the names of the boxes or PID items from the auto-pilot.
Multiwii Read Actuators	Reads the commands for the servos or motors from the auto-pilot.
Multiwii Read Boxes	Reads the box items. Each word in the output array is a bitmask of activation switches.
Multiwii Read GPS	Reads the raw GPS data.
Multiwii Read Miscellaneous	Reads miscellaneous information from the auto-pilot, such as thresholds, triggers and counters.
Multiwii Read PID	Reads PID gains from the auto-pilot.
Multiwii Read RC	Reads RC values from the auto-pilot.
Multiwii Read RC Tuning	Reads RC tuning parameters from the auto-pilot.
Multiwii Read Servo Configuration	Reads the servo configuration from the auto-pilot.
Multiwii Read Waypoint	Reads the current waypoint from the auto-pilot.
Multiwii Reset Configuration	Resets all parameters to defaults in the auto-pilot.
Multiwii Select Setting	Select the setting configuration for the auto-pilot.
Multiwii Status	Gets the status of the auto-pilot.
Multiwii Write Actuators	Writes the commands for the motors to the auto-pilot.
Multiwii Write Boxes	Writes box items to the auto-pilot. Each word in the input array is a bitmask of activation switches.
Multiwii Write GPS	Writes raw GPS data to the auto-pilot. The data is injected into the GPS stream.
Multiwii Write Miscellaneous	Writes miscellaneous information from the auto-pilot, such as thresholds, triggers and counters.
Multiwii Write PID	Writes PID gains to the auto-pilot.
Multiwii Write RC	Writes raw RC values to the auto-pilot.
Multiwii Write RC Tuning	Writes RC tuning parameters to the auto-pilot.
Multiwii Write Servo Configuration	Writes the servo configuration to the auto-pilot.
Multiwii Write Waypoint	Writes a new waypoint to the auto-pilot.

NEES Communication Blocks

The NEES communication blocks have been deprecated.

The NEES block set is designed to enable QUARC Simulink models to communicate with Quanser NEES Daemon. This set consists of blocks to connect to the daemon, and send/receive signals to/from it.

NEES Get Signals	Receives signals from the Quanser NEES Daemon.
NEES Initialize	Initializes a connection between the Simulink model and the Quanser NEES Daemon.
NEES Set Signals	Sends signals to Quanser NEES Daemon.

S.BUS Communication Blocks

The S.BUS block set is designed to enable QUARC Simulink models to communicate with and emulate S.BUS receivers.

SBus Read block	Reads an S.BUS frame and outputs its constituent parts.
SBus Write block	Writes an S.BUS frame to the given stream.

Serial Receiver Communication Blocks

The Serial Receiver block set is designed to enable QUARC Simulink models to communicate with and emulate serial receivers.

Serial Receiver Read block	Receives RC commands from a serial receiver.
Serial Receiver Write block	Emulates RC commands sent from a serial receiver.

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