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Using the External Mode User Interface
Selecting signal tells external mode to start logging data when a selected
trigger signal satisfies trigger conditions specified in the Trigger signal
panel. When the trigger conditions are satisfied (that is, the signal crosses
the trigger level in the specified direction) a trigger event occurs. If the
trigger is armed, external mode monitors for the occurrence of a trigger
event. When a trigger event occurs, data logging begins.
• Arm when connect to target: If this option is selected, external mode
arms the trigger automatically when Simulink connects to the target. If
the trigger source is manual, uploading begins immediately. If the trigger
mode is signal, monitoring of the trigger signal begins immediately, and
uploading begins upon the occurrence of a trigger event.
If Arm when connect to target is not selected, you must manually arm
the trigger by clicking the Arm trigger button in the External Mode
Control Panel.
• Duration: The number of base rate steps for which external mode logs
data after a trigger event. For example, if the fastest rate in the model is 1
second and a signal sampled at 1 Hz is being logged for a duration of 10
seconds, then external mode will collect 10 samples. If a signal sampled at
2 Hz is logged, only 5 samples will be collected.
• Mode: normal or one-shot. In normal mode, external mode automatically
rearms the trigger after each trigger event. In one-shot mode, external
mode collects only one buffer of data each time you arm the trigger. See
“Data Archiving” on page 6-19 for more details on the effect of the Mode
setting.
• Delay: The delay represents the amount of time that elapses between a
trigger occurrence and the start of data collection. The delay is expressed
in base rate steps, and can be positive or negative. A negative delay
corresponds to pretriggering. When the delay is negative, data from the
time preceding the trigger is collected and uploaded.
Trigger Signal Selection
You can designate one signal as a trigger signal. To select a trigger signal,
select signal from the Trigger Source menu. This activates the Trigger
signal panel (see the figure below). Then, click the desired entry in the
Signal selection list and click the Trigger signal button.
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