PicoScope 3000 Series User Guide
27
Copyright 2005 Pico Technology Limited. All rights reserved.
PS3000044 1.4
The
ps3000_get_times_and_values ()
function will always return FALSE (0) in streaming
mode.
3.4.4
Triggering
The PicoScope 3000 Series PC Oscilloscope can either start collecting data immediately,
or it can be programmed to wait for a trigger event to occur. In either case, you need to
use the
function. A trigger event can occur when the channel A or
B input crosses a threshold voltage, or when an external trigger input crosses a threshold
voltage. The trigger event can be either a rising or a falling edge.
The external trigger input uses the same physical connection as the signal generator
output, so these two functions cannot be used at the same time. It is possible, however,
to use the output from the signal generator as a trigger. Triggering is available in block
mode only. Any call to the
function has no effect in streaming
mode.
3.4.5
ETS (Equivalent Time Sampling)
ETS is a way of increasing the effective sample rate when working with repetitive signals.
It is not possible to use ETS with one-shot signals. ETS is controlled by the
and
functions. ETS is available in block mode
only. Calls to the
function have no effect in streaming mode. As
ETS will return random time intervals, the
ps3000_get_times_and_values ()
function must
function will return FALSE (0).
Only the 3204/5/6 variants provide ETS.
3.4.6
Voltage ranges
It is possible to set the gain for each channel with the
function.
This will give an input voltage range between ±20 mV (for the 3224 and 3424) or ±100 mV
(for the 3204/5/6) and ±20V. The external trigger has a fixed input range of ±20 V.
3.4.7
AC/DC operation
function, each channel can be set to either AC or DC
coupling. When AC coupling is used, any DC component of the signal is filtered out.
3.4.8
Oversampling
When the oscilloscope is operating in block mode at speeds less than the maximum, it is
possible to oversample. Oversampling is taking more than one measurement during a
time interval and returning an average. This reduces the effects of noise, and increases
the effective vertical resolution of the oscilloscope.
