Installation guide

PicoScope 4000 Series (A API) Programmer's Guide 9

Downsampling. When the data has been collected, you can set an optional

downsampling factor and examine the data. Downsampling is the process of

reducing the amount of data by combining adjacent samples using one of several

algorithms. It is useful for zooming in and out of the data without having to

repeatedly transfer the entire contents of the scope's buffer to the PC.

Memory segmentation. The scope's internal memory can be divided into

segments so that you can capture several waveforms in succession. Configure this

using ps4000aMemorySegments.

Data retention. The data is lost when a new run is started in the same segment,

the number of segments is changed, or the scope is powered down.

See Using block mode for programming details.

3.6.1.1

Using block mode

This is the general procedure for reading and displaying data in block mode using a

single memory segment:

1. Open the oscilloscope using ps4000aOpenUnit.

2. Select channel ranges and AC/DC coupling using ps4000aSetChannel.

3. Using ps4000aGetTimebase, select timebases until the required nanoseconds

per sample is located.

4. Use the trigger setup functions

[1] [2] [3] [4]

to set up the trigger if required.

5. Start the oscilloscope running using ps4000aRunBlock.

6. Wait until the oscilloscope is ready using the ps4000aBlockReady callback.

7. Use ps4000aSetDataBuffer to tell the driver where your memory buffer is.

8. Transfer the block of data from the oscilloscope using ps4000aGetValues.

9. Display the data.

10. Repeat steps 5 to 9.

11. Stop the oscilloscope using ps4000aStop.

12. Request new views of stored data using different downsampling parameters: see

Retrieving stored data.