Synchronizing digital and analog tasks

[jrolston]

From looking at the SyncAI_ReadDigChan example for .NET, it appears that all you need to do to synchronize digital and analog tasks is to have them share a sample clock.  There's no need to share any triggers.  So, I hope this isn't too naive a question, but why doesn't this work for all types of synchronization?  If an AI and an AO task are sharing the same sample clock, why do they need a common trigger as well?

[mallorim]

Hi jrolston,

This is a valid question. The reason that no shared start trigger is necessary when synchronizing Analog and Digital IO tasks is that Digital IO does not have its own timing engine. Digital IO is typically performed with software updates. In the case of synchronizing Digital IO with an Analog Input task, a sample clock has been generated using the Analog Input’s timing engine. This sample clock starts when the Analog task starts. Since the Digital IO task is using that clock, it too will begin on the first edge of the clock. Therefore, a start trigger is not necessary.

In the case of synchronizing Analog Input and Analog Output, they have two separate timing engines and therefore need to be started at the same time with a start trigger.

Hope this explanation helps, Mallori M.