Query number of records in device buffer?

[RatedPG]

Does anyone know of a way to query the number of records left to read in a device's memory? I am using a PXI-5105 digitizer card to record somewhat random events over a 15 second interval. The task is set to trigger off of a rising edge on channel 0 and records a finite number of samples around the trigger event. Because the event is somewhat random, there will be from 900 to 1500 records created. Is there a way I could "see" how many records or trigger "events" have been recorded before I begin my asynchronous Read call? I would like to dispose of the task after I clear the buffer out and reconfigure a new task in time for the next series of events. (The next series of events require a different task configuration.) Thanks, -Prescott Glynn

[David L.]

Hi Prescott,

There are two scope properties that I believe may help. The first is ‘RecordsDone()’ (found under ScopeAcquisition), which Specifies the number of records that have been completely acquired. This one should let you ‘see’ the number of records (triggers) that have happened. The second is ‘GetBacklog’ (Found under either ScopeMultipleRecordReder orScopeSingleRecordReader), which returns the number of samples that have been acquired, but not fetched. I think the ‘recordsdone’ is more applicable for your application, but wanted to mention ‘GetBacklog’ to make you aware.