2.2 Zero Suppression

One of the Ndigo6G-12’s key features is on-board zero suppression to reduce PCIe bus load. Only data that passes specifications predefined by the user is transmitted. Data is transmitted as so-called “packets.” For the ADC channels, the packet contains the waveform data and a timestamp giving the absolute time (i.e., the time since the start of the data acquisition) of the packet’s first sample.

Figure 2.7 shows a simple example: Data is only written to the PC if the sample values exceed a specific threshold. Expanding on that, the Ndigo6G-12’s zero suppression can be used to realize much more complex scenarios using the Trigger and Gating Blocks (see Sections 2.3 and 2.4).

Figure 2.7: Simple zero suppression: Only data with values above a threshold are written to the PC.