Programming and Data Types

Starting and Stopping Timers

After you create a timer object, you can start the timer by calling either the start or startat function.

Note    Because the timer works within the MATLAB single-threaded environment, it cannot guarantee execution times or execution rates.

The start function starts the timer immediately, changing the value of the timer object's Running property from 'off' to 'on':

• t = timer('TimerFcn','disp(''Hello World!'')','StartDelay',15);
  start(t)
  

The start function returns control to the MATLAB command line immediately. You can also choose to wait until the timer callback function (TimerFcn) executes before returning control to the command line. See Blocking the MATLAB Command Line for more information.

The startat function starts the timer immediately and sets the value of the StartDelay property to the time you specify:

• t2=timer('TimerFcn','disp(''It has been an hour now.'')');
  startat(t2,now+1/24);
  

Note    The timer object can execute a callback function that you specify when it starts. See Creating Timer Callback Functions for more information about using the StartFcn property.

Blocking the MATLAB Command Line

By default, when you start a timer, the start or startat function returns control to the command line immediately. If your application must wait until the function controlled by the timer executes, use the wait function right after calling the start function:

• t = timer('StartDelay',15,'TimerFcn','disp(''Hello World!'')');
  start(t)
  wait(t)
  

Stopping Timers

The timer stops running if one of the following conditions apply:

• The timer function callback (TimerFcn) has been executed the number of times specified in the TasksToExecute property.
• The stop command is issued.
• An error occurred while executing a timer function callback (TimerFcn).

When a timer stops, the value of the Running property of the timer object is 'off'.

Note    The timer object can execute a callback function that you specify when it stops. See Creating Timer Callback Functions for more information about using the StopFcn property.

Timer Object Properties

Timer Object Execution Modes