| Data Acquisition Toolbox | |
Timer Events
The only event supported by digital I/O objects is a timer event. Timer events occur after a specified period of time has passed. Properties associated with generating timer events are given below.
| Property Name |
Description |
Running |
Indicates if the device object is running. |
TimerAction |
Specifies the M-file action function to execute whenever a predefined period of time passes. |
TimerPeriod |
Specifies the period of time between timer events. |
A timer event is generated whenever the time specified by TimerPeriod passes. This event executes the action function specified for TimerAction. Time is measured relative to when the device object starts running (Running is On). Starting a digital I/O object is discussed in the next section.
Some timer events may not be processed if your system is significantly slowed or if the TimerPeriod value is too small. For example, a common application for timer events is to display data. However, since displaying data can be a CPU-intensive task, some of these events may be dropped. For digital I/O objects, timer events are typically used to display the state of the device object. Refer to the diopanel demo for an example that generates timer events to update the state of a digital I/O object.
To see how to construct an action function, refer to Creating and Executing Action Functions or the example below.
| | Generating Timer Events | Starting and Stopping a Digital I/O Object | |