HIL Read

Reads the specified channels immediately.

Library

QUARC Targets/Data Acquisition/Generic/Immediate I/O MATLAB Command Line Click to copy the following command line to the clipboard. Then paste it in the MATLAB Command Window: qc_open_library('quarc_library/Data Acquisition/Generic/Immediate I//O')

Description

The HIL Read block reads the specified channels every time the block is executed. This block can read more than one type of channel at the same time. The channels are read immediately. Using this block is more efficient than using separate blocks for each channel type when more than one type of channel is being read.

The other outputs of the block will be assigned appropriate SI units, if possible. When the other outputs are a single vector then units are only assigned if every element would have the same units.

All the channels which will be used as digital inputs must be entered in the Digital input channels field of the Digital Inputs pane in the HIL Initialize block's parameters dialog. Doing so ensures that those channels will be configured as inputs when using a card for which the digital I/O lines are programmable as inputs or outputs. Failure to configure these channels in the Digital input channels field as inputs may result in the HIL Read block failing to read those inputs.

Input Ports

This block has no input ports.

Output Ports

The number of output ports depends on the Vector output parameter. If this option is off then there is one output port for each channel and each port outputs the value read from the corresponding channel. If this option is on then there is one output port for each channel type for which channels are defined, and each output is a vector containing the values read from the channels specified in the corresponding Channels parameter for that channel type. If the option is grouped, then there will be an output port for each consecutive group of channels within each channel type. Refer to the documentation on the Vector output parameter below for more details.

For scalar outputs, the signal will have units commensurate with the corresponding channel. For vector outputs, the signal will only have units if all the channels corresponding to each element of the vector have the same units.

Data Type Support

The HIL Read block outputs signals of type double for the analog and other channels, it outputs signals of type int32 or double for the encoder channels and it outputs any of the built-in Simulink datatypes except fixed point for the digital channels. See the Signal Data Types pane below for information on how the output data type is determined.

Parameters and Dialog Box

Individual Panes

• Main
• Signal Data Types

Main Pane

The Main pane of the dialog appears as follows:

Board Name

The name of the board whose analog channels will be read. Boards are configured using the HIL Initialize block. Place an HIL Initialize block in your diagram to add a board name to the list.

Analog channels

The analog channels to read. The number of analog channels available depends on the board selected. Refer to Channels for more information. The output is the voltages read from the analog inputs.

Select a board type from the list for board-specific details:

Encoder channels

The encoder channels to read. The number of channels available depends on the board selected. Refer to Channels for more information. The output is the count values read from the encoder counters.

Select a board type from the list for board-specific details:

Digital channels

The digital channels to read. The number of channels available depends on the board selected. Refer to Channels for more information. The output is the states read from the digital inputs.

Select a board type from the list for board-specific details:

Other channels

The other channels to read. The number of channels available depends on the board selected. Refer to Other Channels for more information about other channels in QUARC. The output is the values read from the other inputs.

Most boards do not support other channels. Select a board type from the list for board-specific details:

Sample time

The sample time of the block. A sample time of 0 indicates that the block will be treated as a continuous time block. A positive sample time indicates that the block is a discrete time block with the given sample time.

A sample time of -1 indicates that the block inherits its sample time. Since this is a source block, only inherent the sample time when it is placed in a conditionally executed subsystem, like a Triggered or Enabled Subsystem, or in a referenced model.

The default sample time is set to qc_get_step_size, which is a QUARC function that returns the fundamental sampling time of the model. Hence, the default sample time is a discrete sample time with the same sampling time as the fixed step size of the model.

Vector outputs

If this option is set to on then the block will have a vector output for each type of channel for which channels are defined, with one element in the vector for each channel of that type. The values read from each channel will appear in the vector in the same order as the corresponding Channels parameter for that type.

For example, if analog channels 3 and 4 are selected, then the first output port will be a 2-vector with the first element containing the voltages read from analog input 3 and the second element containing the voltages read from analog input 4. Each output port will be labeled with the prefix indicating the type of channel represented by that output port. Refer to the table below for an explanation of the prefixes used.

If this option is set to grouped then the block will have one output for each consecutive group of channels within each channel type. The output ports will appear in the same order as the channels in the corresponding Channels parameter for that type. Each port will be labeled with the prefix indicating the type of channel followed by the first channel in the corresponding group. Refer to the table below for an explanation of the prefixes used. Note that the Channels parameters will not be tunable offline when the outputs are grouped because the channel numbers themselves determine the number of outputs.

To force grouped channels that are naturally consecutive to appear as separate outputs, simply change the order so that they are not consecutive. For example, a channel selection of [0, 1, 2] will appear as a single vector, but a channel selection of [2, 1, 0] will appear as three separate outputs, the first for channel 2, the next for channel 1 and the last for channel 0. Finally, a channel selection of [2, 0, 1] will appear as a scalar output for channel 2 and a 2-vector output for channels 0 and 1.

If this option is set to off then the block will have one output for each channel. The output ports will appear in the same order as the channels in the Analog channels, Encoder channels, Digital channels amd Other channels parameters. Each port will be labeled with a prefix indicating the channel type and the corresponding channel number. The prefixes are:

Port labels

This parameter allows the labels on the port to be changed to reflect the channel numbers or the signal names, when signal names are available. The table below enumerates the different display options. This parameter has no effect on generated code.

Signal Data Types Pane

The Signal Data Types pane of the dialog appears as follows:

Output data type mode

Sets the data type of the output to be inherited by back propagation or to be specified explicitly in the dialog. This parameter only affects the encoder and digital channels. The analog and other channels are always double.

If back propagation is selected then the data type of the encoder and digital outputs will be determined by the blocks to which these outputs are connected. If an encoder output is not connected or it is connected to a block which supports multiple datatypes, then the output data type will be double. If a digital output is not connected or it is connected to a block which supports multiple datatypes, then the output data type will be boolean.

Otherwise the data type of the encoder outputs can be specified explicitly using the Encoder output data type parameter and the data type of the digital outputs can be specified explicitly using the Digital output data type parameter.

Encoder output data type

Sets the data type of the encoder outputs explicitly.

Digital output data type

Sets the data type of the digital outputs explicitly.

Targets

See Also

• Accessing Hardware
• MATLAB Hardware Functions
• Hardware-in-the-Loop C API

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