Filter
Top Products
PicoScope 2104 & 2105 PC Oscilloscope User Guide
20
Copyright 2006 Pico Technology Limited. All rights reserved.PS2100044-1.0
3.4
Advanced features
3.4.1
Sampling modes
A PicoScope PC Oscilloscope can run in various sampling modes. At high sampling
rates, the oscilloscope collects data much faster than a PC can read it. To compensate
for this, the oscilloscope stores a block of data in an internal memory buffer, delaying
transfer to the PC until a preset number of data points has been sampled. This is
called block mode. At very low sampling rates, you may want to switch to
streaming mode. This allows accurately timed data to be transferred back to the PC,
without gaps. Real-time continuous mode is also provided for use at low sampling
rates, and allows capture of data from multiple converters.
Sampling mode support in Pico software
Block Streaming Real-time
continuous
PicoScope Yes * † Yes * † No
PicoLog Yes * Yes * Yes
*
Only with a single converter
† PicoScope automatically selects block or streaming mode
3.4.2
More on block mode
In block mode, the computer prompts a unit to collect a block of data into its internal
memory. When the oscilloscope has collected the whole block, it will signal it is ready,
and transfer the whole block into computer memory via the USB port.
The maximum number of values depends upon the size of the oscilloscope's memory.
A PicoScope PC Oscilloscope can sample at a number of different rates, which
correspond to the maximum sampling frequency divided by 1, 2, 4, 8 and so on.
The PicoScope 2000 Series driver normally performs a number of setup operations
before collecting each block of data. This can take up to 50 milliseconds. If it is
necessary to collect data with the minimum time interval between blocks, avoid calling
setup functions between calls to ps2000_run_block(), ps2000_ready(),
ps2000_stop() (not normally used) and ps2000_get_values().