MATLAB Programming

Timer Object Execution Modes
Timer Object Execution Modes
The timer object supports several execution modes that determine how it
schedules the timer callback function (TimerFcn) for execution. You specify
the execution mode by setting the value of the ExecutionMode property. This
section describes
• “Executing a Timer Callback Function Once” on page 10-19
• “Executing a Timer Callback Function Multiple Times” on page 10-20
• “Handling Callback Function Queuing Conflicts” on page 10-21
Executing a Timer Callback Function Once
To execute a timer callback function once, set the ExecutionMode property to
'singleShot'. Thisisthedefaultexecutionmode.
In this mode, the timer object starts the timer and, after the time period
specified in the StartDelay property elapses, adds the timer callback function
(TimerFcn) to the MATLAB execution queue. When the timer callback
function finishes, the timer stops.
The following figure graphically illustrates the parts of timer callback
execution for a singleShot execution mode. The shaded area in the figure,
labelled queue lag, represents the indeterminate amount of time between
when the timer adds a timer callback function to the MATLAB execution
queue and when the function starts executing. The duration of this lag is
dependent on what other processing MATLAB happens to be doing at the time.
Timer Callback Execution (singleShot Execution Mode)
10-19