User Manual

Programming with the PicoScope 4000 Series14

);

ps4000GetTriggerTimeOffset64

(

handle,

&time,

&timeUnits,

index

)

}

Comments: each waveform is retrieved one at a time from the driver with an

aggregation of 1000.

4.6.3

ETS (Equivalent Time Sampling)

Note: ETS mode is not supported by the PicoScope 4262 oscilloscope.

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

ps4000SetTrigger and ps4000SetEts 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 adds a short,

variable delay, which is a small fraction of a single sampling interval, between each

trigger event and the subsequent sample. This shifts each capture slightly in time

so that the samples occur at slightly different times relative to those of the previous

capture. 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

ps4000BlockReady 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.

4.6.3.1

Using ETS mode

Since ETS mode is a type of block mode, the procedure is the same as the one

described in Using block mode.