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XCP UDP Data Acquisition

Acquire selected measurements from configured server connection

Since R2019a

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  • XCP UDP Data Acquisition block

Libraries:
Vehicle Network Toolbox / XCP Communication / UDP
Simulink Real-Time / XCP / UDP

Description

The XCP UDP Data Acquisition block acquires data from the configured server connection based on the measurements that you select. The block uses the XCP UDP transport layer to obtain raw data for the selected measurements at the specified simulation time step. Configure your XCP connection and use the XCP UDP Data Acquisition block to select your event and measurements for the configured server connection. The block displays the selected measurements as output ports.

The XCP communication blocks support the use of Simulink® accelerator mode and rapid accelerator mode. You can speed up the execution of Simulink models by using these modes. For more information on these simulation modes, see Design Your Model for Effective Acceleration.

Parameters

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Select the name of XCP configuration that you want to use. This list displays all available names specified in the XCP UDP Configuration blocks in the model. Selecting a configuration displays events and measurements available in the A2L file of this configuration. You can acquire measurements for only one event by using an XCP UDP Data Acquisition block. Use one block for each event whose measurements you want to acquire.

Select an event from the available list of events. The XCP UDP Configuration block uses the specified A2L file to populate the events list.

This list displays all measurements available for the selected event. Select the measurement that you want to use and click the add button, to add it to the selected measurements. Hold the Ctrl key on your keyboard to select multiple measurements.

In the Block Parameters dialog box, type the name of the measurement you want to use in the Search box. The All Measurements lists displays a list of all matching names. Click the x to clear your search.

This list displays selected measurements. To remove a measurement from this list, select the measurement and click the remove button, .

In the Block Parameters dialog box, use the toggle buttons to reorder the selected measurements.

This parameter enables support for XCP data types and dimensions as defined in the ASAP2 standard. The Block Output Settings parameter selects whether the port outputs Compu method conversion values or raw values. The options provide:

  • Physical values (apply Compu method conversion) enables the raw-to-physical conversion of ECU measurement values. For this option, the block port settings are set either to 'double' or 'string', based on the underlying Compu method conversion. For example, Compu method IDENTICAL, LINEAR, RAT_FUNC, TAB_INTP, and TAB_NOINTP port settings is 'double' while Compu method TAB_VERB port settings is 'string'. The maximum string length supported for Compu method conversion is 1024 as specified in the ASAM XIL specification.

    The FORM Compu method conversion is not supported. Simulink throws a warning for such a conversion and IDENTICAL conversion is applied to the underlying measurement. Also, only scalar measurement signals are supported for TAB_VERB conversion as Simulink only supports scalar strings.

    Selecting this option shows the physical units (if any) in front of the measurement name on the block mask. This physical unit is acquired from the A2L description of the measurement and Compu method. If the physical unit is not specified, only the measurement name is displayed.

  • Raw values (no Compu method conversion) sets the port data type according to the type definition in the A2L file and supports up to three-dimensional XCP measurements in Simulink.

  • Raw values as double (no Compu method conversion) sets the port data type as double, converting all internal measurement values. This selection supports up to three-dimensional XCP measurements in Simulink.

These ASAP2 data types are supported by corresponding Simulink port data types:

  • SBYTE

  • UWORD

  • SWORD

  • ULONG

  • SLONG

  • A_UINT64

  • A_INT64

  • FLOAT32_IEEE

  • FLOAT64_IEEE

The dimension support in the block accommodates the different treatment of matrices by MATLAB® and the ECU. The MATLAB default operation treats matrices as row-major matrices. An XCP measurement can have a LAYOUT as COLUMN_DIR or ROW_DIR . If a matrix measurement is COLUMN_DIR, the blocks rearrange the measurement in memory and ensure that the matrix (row X, col Y) in MATLAB refers to the same entry as (row X, col Y) on the ECU. The rearrangement causes matrix entries that are contiguous on the ECU to be noncontiguous in MATLAB and Simulink.

Specify a priority value as an integer from 0 to 255 for the server device driver to prioritize transmission of data packets. The server can accumulate XCP packets for lower priority DAQ lists before transmission to the client. A value of 255 has the highest priority. The SET_DAQ_LIST_MODE command communicates the DAQ List Priority value from client to server. This communication method differs from the specification of the Event Channel Priority property, which comes from the A2L file.

Specify the sampling time of the block during simulation, which is the simulation time. This value defines the frequency at which the XCP UDP Data Acquisition block runs during simulation. If the block is inside a triggered subsystem or is to inherit sample time, you can specify –1 as your sample time, which is the default. You can also specify a MATLAB variable for sample time. For information about simulation sample timing, see What Is Sample Time?.

When the Timestamp is enabled, the block reads the timestamp from incoming DTO packets and outputs the timestamp to Simulink. The Enable Timestamp check box appears in the block parameters dialog box when the parameter is supported in the A2L file.

Extended Capabilities

Version History

Introduced in R2019a

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See Also

Blocks