ASYNC_ATTR_INTERVAL
| Data Type: | decimal |
| Access: | read/write |
| Functions: | SetAsyncTimerAttribute GetAsyncTimerAttribute |
| Description: | Specifies the wait interval, in seconds, between timer events. The minimum interval value that you can use depends on the system that is running the asynchronous timer. If the interval is smaller than the asynchronous timer resolution supported by your system, LabWindows/CVI uses an interval equal to the resolution supported by the system. Call GetAsyncTimerResolution to get the asynchronous timer resolution for your system. If the timer has already started, setting ASYNC_ATTR_INTERVAL resets the timer. Asynchronous timer tick events can accumulate when the library thread responsible for generating timer tick events is unable to call the callback function at the specified interval. For example, the library thread could fall behind if the time to complete the callback function is longer than the specified interval. When asynchronous timer tick events accumulate, the library thread dispatches the accumulated events as quickly as possible. In this case, the interval at which the library thread generates events might be shorter than the interval you specified when you created the asynchronous timer. If the cause for the accumulated events is temporary and the library thread finishes generating the accumulated events, the library thread resumes generating events at the interval you specified when you created the asynchronous timer. On Windows, all asynchronous callback functions share a common thread. As a result, the duration of any asynchronous callback function can have an impact on all other asynchronous timers, possibly causing timer tick events to accumulate. |
| LabWindows/CVI Compatibility: |
LabWindows/CVI 5.0 and later |