User`s guide

Plots Not Visible in Simulink Scope Block
5-3
Plots Not Visible in Simulink Scope Block
For data to plot correctly in a Simulink Scope block, you must specify the
following:
•
External mode selected from the Simulation menu in the Configuration
Parameters
dialog
•
Connect to target selected from the Simulation menu
• Select one or more signals for capture (designated with “X”) in the
External
Signal & Triggering
dialog box from the Tools->External Mode Control
Panel
menu.
•
Duration * Fixed Step Size close to or less than the X range in the Scope
block
• Correct mode (
one-shot vs. normal)
• Appropriate signal levels to allow triggering
• Y range on Simulink Scope block axes large enough to span the signal
amplitude
• X range
•
Arm when connect to target in the External Signal & Triggering dialog
box or
Arm Trigger in the External Mode Control Panel
• Start real-time code selected from the Simulation menu
If you are unable to see signals plotted in your Simulink Scope blocks after all
of the above items have been selected, your system might have insufficient
CPU time. To determine CPU utilization, type
rtwho. The rtwho command
returns information about MATLAB performance. The value returned is an
indicator of how much loading your model places on the CPU. If Scope blocks
fail to plot, this can be an indication that insufficient time is available between
sample intervals to allow data to be transferred back to the MATLAB
environment where the plotting is performed. To test for this condition, you can
run one of the demonstration models, or you can try running your model at a
significantly slower rate to determine whether this is the cause. We
recommend that MATLAB performance not fall below 80%.