Backing Store

Backing store is a feature that stores the current waveform on the NI-SCOPE Soft Front Panel in RAM. During normal operation, the NI-SCOPE SFP gets the data from the digitizer, decimates and scales it for display, displays it, then discards it. This process saves time and memory, especially when working with large data sets. With large data sets, the data is never all in memory at one time, because it is read from the digitizer in chunks and decimated in chunks. The NI-SCOPE SFP scales this decimated data. The disadvantage of this process is that you must wait for an acquisition to finish before you get data that you can save. If you have a signal on the NI-SCOPE SFP that you want to save, you may not be able to do so unless the acquisition is currently paused, depending on the length of the waveform.

To save a waveform, the NI-SCOPE SFP copies chunks of data from the digitizer directly to disk, which prevents a memory hit. If your acquisition is in progress, the data that is currently displayed is lost, and you must wait until the acquisition is complete before saving data. Using single-shot mode is usually recommended if you want to save the displayed data. When the digitizer pauses, the data is preserved because another acquisition is not initiated. If backing store is enabled, the current waveform is stored in memory and you can save at any time.

Backing store is enabled by default. If you are using an older computer, however, you may experience reduced performance and higher memory requirements. Disabling backing store may solve these problems.