Documentation

Signal logging data buffer size in doubles

Enter the maximum number of sample points that the software stores before wrapping.

Settings

Default: 100000

The maximum value for this option cannot exceed the available target computer memory, which the Simulink® Real-Time™ software also uses to hold other items.

Tips

  • Real-time applications use this buffer to store the time, states, outputs, and task execution time (TET) logs as defined in the Simulink model.

  • The maximum value for this option derives from available target computer memory, which the Simulink Real-Time software also uses to hold other items. For example, in addition to signal logging data, the software also uses the target computer memory for the Simulink Real-Time kernel, real-time application, and scopes.

    For example, assume that your model has six data items (time, two states, two outputs, and task execution time). If you enter a buffer size of 100000, the target object property tg.MaxLogSamples is calculated as floor(100000 / 6) = 16666. After the buffer saves 16666 sample points, it wraps and further samples overwrite the older ones.

  • Suppose that you enter a logging buffer size larger than the available RAM on the target computer. When you download and initialize the real-time application, the target computer displays a message, ERROR: allocation of logging memory failed. To avoid this error, either install more RAM or reduce the buffer size for logging, and then restart the target computer. To calculate the maximum buffer size available for your real-time application logs, divide the amount of available RAM on your target computer by sizeof(double), or 8. Enter that value for the Signal logging data buffer size in doubles value.

Command-Line Information

Parameter: RL32LogBufSizeModifier
Type: character vector
Value: '100000' | A valid memory size
Default: '100000'
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