User manual

PicoScope 6000 Series Programmer's Guide 15

3.5.3

ETS (Equivalent Time Sampling)

ETS is a way of increasing the effective sampling rate of the scope when capturing

repetitive signals. It is a modified form of block mode, and is controlled by the

ps6000SetTrigger and ps6000SetEts functions.

Overview. ETS works by capturing several cycles of a repetitive waveform, then

combining them to produce a composite waveform that has a higher effective

sampling rate than the individual captures. The scope hardware accurately

measures the delay, which is a small fraction of a single sampling interval, between

each trigger event and the subsequent sample. The driver then shifts each capture

slightly in time and overlays them so that the trigger points are exactly lined up.

The result is a larger set of samples spaced by a small fraction of the original

sampling interval. The maximum effective sampling rates that can be achieved with

this method are listed in the User's Guide for the scope device.

Trigger stability. Because of the high sensitivity of ETS mode to small time

differences, the trigger must be set up to provide a stable waveform that varies as

little as possible from one capture to the next.

Callback. ETS mode returns data to your application using the ps6000BlockReady

callback function.

Applicability

Available in block mode only.

Not suitable for one-shot (non-repetitive) signals.

Aggregation and oversampling are not supported.

Edge-triggering only.

Auto trigger delay (autoTriggerMilliseconds) is ignored.