pico Technology PicoScope 2000 Series Programmer's Guide

Sampling modes
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PicoScope 2000 Series Programmer's Guide
3.2 Streaming mode
Streaming mode is an alternative to block mode that can capture data without gaps between
blocks.
In streaming mode, the computer prompts the oscilloscope to start collecting data. The data is
then transferred back to the PC without being stored in the oscilloscope's memory. Data can
be sampled with a period between 1 µs or less and 60 s, and the maximum number of
samples is limited only by the amount of free space on the PC's hard disk.
There are two varieties of streaming mode:
Compatible streaming mode
Fast streaming mode
3.2.1 Compatible streaming mode
Compatible streaming mode is a basic streaming mode that works at speeds from one
sample per minute to a thousand samples per second.
The oscilloscope's driver transfers data to a computer program using either normal or
windowed mode. In normal mode, any data collected since the last data transfer operation is
returned in its entirety. Normal mode is useful if the computer program requires fresh data on
every transfer. In windowed mode, a fixed number of samples is returned, where the oldest
samples may have already been returned before. Windowed mode is useful when the program
requires a constant time period of data.
Once the oscilloscope is collecting data in compatible streaming mode, any setup changes (for
example, changing a channel range or AC/DC setting) will cause a restart of the data stream.
The driver can buffer up to 32 kilosamples of data per channel, but the user must ensure that
the ps2000_get_values function is called frequently enough to avoid buffer overrun.
For streaming with the PicoScope 2202, 2203, 2204, 2204A, 2205 and 2205A variants, we
recommend you use fast streaming mode instead.
Applicability
Only recommended for use with PicoScope 2104 and 2105.
Does not support triggering.
The ps2000_get_times_and_values function always returns FALSE (0)
in streaming mode.
See Using compatible streaming mode for programming details.
3.2.1.1 Using compatible streaming mode
This is the general procedure for reading and displaying data in compatible streaming mode:
1. Open the oscilloscope using ps2000_open_unit.
2. Select channel ranges and AC/DC coupling using ps2000_set_channel.
3. Start the oscilloscope running using ps2000_run_streaming.
4. Transfer the block of data from the oscilloscope using ps2000_get_values.
5. Display the data.
6. Repeat steps 4 and 5 as necessary.
7. Stop the oscilloscope using ps2000_stop.

pico Technology PicoScope 2000 Series Specifications

General

Brand	pico Technology
Model	PicoScope 2000 Series
Category	Test Equipment
Language	English