PicoScope 5000 Series (A API) Instrument Driver Oscilloscope Rapid Block Data Capture Example
This is an example of an instrument control session using a device object. The instrument control session comprises all the steps you are likely to take when communicating with your instrument.
These steps are:
- Create a device object
- Connect to the instrument
- Configure properties
- Invoke functions
- Disconnect from the instrument
To run the instrument control session, type the name of the file, PS5000A_ID_Rapid_Block_Example, at the MATLAB command prompt.
The file, PS5000A_ID_RAPID_BLOCK_EXAMPLE.M must be on your MATLAB PATH. For additional information on setting your MATLAB PATH, type 'help addpath' at the MATLAB command prompt.
Example: PS5000A_ID_Rapid_Block_Example;
Description: Demonstrates how to call functions in order to capture a series of waveforms using rapid block mode on a PicoScope 5000 Series Oscilloscope using the underlying 'A' API library functions.
Copyright: © 2013-2018 Pico Technology Ltd. See LICENSE file for terms.
Contents
- Suggested input test signals
- Clear command window and close any figures
- Load configuration information
- Device connection
- Set channels
- Set device resolution
- Set memory segments
- Verify timebase index and maximum number of samples
- Set simple trigger
- Set rapid block parameters and capture data
- Obtain the number of captures
- Process data
- Stop the device
- Disconnect device
Suggested input test signals
This example was published using the following test signal:
- Channel A: 4 Vpp Swept sine wave (Start: 10 kHz, Stop: 100 kHz, Sweep type: Up, Increment Time: 1 ms, Increment type: Linear, Mode: Continous)
- Channel B: 2 Vpp Swept square wave (Start: 10 kHz, Stop: 50 kHz, Sweep type: Up, Increment: 5 kHz, Increment Time: 1 ms)
Clear command window and close any figures
clc;
close all;
Load configuration information
PS5000aConfig;
Device connection
% Check if an Instrument session using the device object |ps5000aDeviceObj| % is still open, and if so, disconnect if the User chooses 'Yes' when prompted. if (exist('ps5000aDeviceObj', 'var') && ps5000aDeviceObj.isvalid && strcmp(ps5000aDeviceObj.status, 'open')) openDevice = questionDialog(['Device object ps5000aDeviceObj has an open connection. ' ... 'Do you wish to close the connection and continue?'], ... 'Device Object Connection Open'); if (openDevice == PicoConstants.TRUE) % Close connection to device. disconnect(ps5000aDeviceObj); delete(ps5000aDeviceObj); else % Exit script if User selects 'No'. return; end end % Create a device object. ps5000aDeviceObj = icdevice('picotech_ps5000a_generic', ''); % Connect device object to hardware. connect(ps5000aDeviceObj);
PicoScope 5000 Series (A API) MATLAB Instrument Driver Copyright © 2013-2018 Pico Technology Ltd. All rights reserved. Number of units found: 1 Serial number(s): FY984/0005 Opening PicoScope 5000 Series (A API) device... Instrument Device Object Using Driver : picotech_ps5000a_generic.mdd Instrument Information Type: Oscilloscope Manufacturer: Pico Technology Ltd. Model: PicoScope 5000A, 5000B and 5000D Series Driver Information DriverType: MATLAB generic DriverName: picotech_ps5000a_generic.mdd DriverVersion: 2.2.14.39 Communication State Status: open Default Channel Setup:- ----------------------- Channel A:- Enabled: True Coupling: DC Range: 5 V Analog offset: 0.0 V Channel B:- Enabled: True Coupling: DC Range: 5 V Analog offset: 0.0 V Channel C:- Enabled: True Coupling: DC Range: 5 V Analog offset: 0.0 V Channel D:- Enabled: True Coupling: DC Range: 5 V Analog offset: 0.0 V Turning off Equivalent Time Sampling... Equivalent Time Sampling turned off. Turning off trigger... Trigger turned off. Default Block mode parameters:- Timebase index : 65 Time Interval: 504 ns Number of pre-trigger samples: 0 Number of post-trigger samples: 10000 Total number of samples: 10000 Default Streaming mode parameters:- Streaming interval: 1.00e-06 s Streaming auto stop: 1 Default Signal generator parameters:- Start frequency: 1000 Hz Stop frequency: 1000 Hz Connected to PicoScope 5000 Series (A API) device:- Instrument Model: 5444D Batch/Serial Number: FY984/0005 USB Version: 3.0 Analog Channels: 4 Resolution: 8 bits Bandwidth: 200 MHz Buffer Memory: 512 MS Maximum Sampling Rate: 1 GS/s Signal Generator Type: Arbitrary Waveform Generator 5 V Power Supply connected: True
Set channels
Default driver settings applied to channels are listed below - use the Instrument Driver's ps5000aSetChannel() function to turn channels on or off and set voltage ranges, coupling, as well as analog offset.
% In this example, data is collected on channels A and B. If it is a % 4-channel model, channels C and D will be switched off if the power % supply is connected. % Channels : 0 - 1 (ps5000aEnuminfo.enPS5000AChannel.PS5000A_CHANNEL_A & PS5000A_CHANNEL_B) % Enabled : 1 (PicoConstants.TRUE) % Type : 1 (ps5000aEnuminfo.enPS5000ACoupling.PS5000A_DC) % Range : 8 (ps5000aEnuminfo.enPS5000ARange.PS5000A_5V) % Analog Offset : 0.0 V % Channels : 2 - 3 (ps5000aEnuminfo.enPS5000AChannel.PS5000A_CHANNEL_C & PS5000A_CHANNEL_D) % Enabled : 0 (PicoConstants.FALSE) % Type : 1 (ps5000aEnuminfo.enPS5000ACoupling.PS5000A_DC) % Range : 8 (ps5000aEnuminfo.enPS5000ARange.PS5000A_5V) % Analog Offset : 0.0 V % Find current power source [status.currentPowerSource] = invoke(ps5000aDeviceObj, 'ps5000aCurrentPowerSource'); if (ps5000aDeviceObj.channelCount == PicoConstants.QUAD_SCOPE && status.currentPowerSource == PicoStatus.PICO_POWER_SUPPLY_CONNECTED) [status.setChC] = invoke(ps5000aDeviceObj, 'ps5000aSetChannel', 2, 0, 1, 8, 0.0); [status.setChD] = invoke(ps5000aDeviceObj, 'ps5000aSetChannel', 3, 0, 1, 8, 0.0); end
Set device resolution
% resolution : 12bits [status.setDeviceResolution, resolution] = invoke(ps5000aDeviceObj, 'ps5000aSetDeviceResolution', 12);
ps5000aSetDeviceResolution: Device resolution set to 12 bits.
Set memory segments
Configure the number of memory segments and query ps5000aMemorySegments() to find the maximum number of samples for each segment.
% nSegments : 64 nSegments = 64; [status.memorySegments, nMaxSamples] = invoke(ps5000aDeviceObj, 'ps5000aMemorySegments', nSegments); % Set number of samples to collect pre- and post-trigger. Ensure that the % total does not exceeed nMaxSamples above. set(ps5000aDeviceObj, 'numPreTriggerSamples', 2048); set(ps5000aDeviceObj, 'numPostTriggerSamples', 2048);
Verify timebase index and maximum number of samples
Use the ps5000aGetTimebase2() function to query the driver as to the suitability of using a particular timebase index and the maximum number of samples available in the segment selected, then set the timebase property if required.
To use the fastest sampling interval possible, enable one analog channel and turn off all other channels.
Use a while loop to query the function until the status indicates that a valid timebase index has been selected. In this example, the timebase index of 4 is valid.
% Initial call to ps5000aGetTimebase2() with parameters: % % timebase : 4 % segment index : 0 status.getTimebase2 = PicoStatus.PICO_INVALID_TIMEBASE; timebaseIndex = 4; while (status.getTimebase2 == PicoStatus.PICO_INVALID_TIMEBASE) [status.getTimebase2, timeIntervalNanoseconds, maxSamples] = invoke(ps5000aDeviceObj, ... 'ps5000aGetTimebase2', timebaseIndex, 0); if (status.getTimebase2 == PicoStatus.PICO_OK) break; else timebaseIndex = timebaseIndex + 1; end end fprintf('Timebase index: %d, sampling interval: %d ns\n', timebaseIndex, timeIntervalNanoseconds); % Configure the device object's |timebase| property value. set(ps5000aDeviceObj, 'timebase', timebaseIndex);
Timebase index: 4, sampling interval: 16 ns
Set simple trigger
Set a trigger on channel A, with an auto timeout - the default value for delay is used. The device will wait for a rising edge through the specified threshold unless the timeout occurs first.
% Trigger properties and functions are located in the Instrument % Driver's Trigger group. triggerGroupObj = get(ps5000aDeviceObj, 'Trigger'); triggerGroupObj = triggerGroupObj(1); % Set the |autoTriggerMs| property in order to automatically trigger the % oscilloscope after 1 second if a trigger event has not occurred. Set to 0 % to wait indefinitely for a trigger event. set(triggerGroupObj, 'autoTriggerMs', 1000); % Channel : 0 (ps5000aEnuminfo.enPS5000AChannel.PS5000A_CHANNEL_A) % Threshold : 500 mV % Direction : 2 (ps5000aEnuminfo.enPS5000AThresholdDirection.PS5000A_RISING) [status.setSimpleTrigger] = invoke(triggerGroupObj, 'setSimpleTrigger', 0, 500, 2);
Set rapid block parameters and capture data
Capture a number of waveof and retrieve data values for channels A and B.
% Rapid Block specific properties and functions are located in the % Instrument Driver's Rapidblock group. rapidBlockGroupObj = get(ps5000aDeviceObj, 'Rapidblock'); rapidBlockGroupObj = rapidBlockGroupObj(1); % Block specific properties and functions are located in the Instrument % Driver's Block group. blockGroupObj = get(ps5000aDeviceObj, 'Block'); blockGroupObj = blockGroupObj(1); % Set number of captures - can be less than or equal to the number of % segments. numCaptures = 8; [status.setNoOfCaptures] = invoke(rapidBlockGroupObj, 'ps5000aSetNoOfCaptures', numCaptures);
This example uses the runBlock() function in order to collect a block of data - if other code needs to be executed while waiting for the device to indicate that it is ready, use the ps5000aRunBlock() function and poll the ps5000aIsReady() function until the device indicates that it has data available for retrieval.
% Capture the blocks of data: % segmentIndex : 0 [status.runBlock, timeIndisposedMs] = invoke(blockGroupObj, 'runBlock', 0); % Retrieve rapid block data values: downsamplingRatio = 1; downsamplingRatioMode = ps5000aEnuminfo.enPS5000ARatioMode.PS5000A_RATIO_MODE_NONE; % Provide additional output arguments for the remaining channels e.g. chC % for Channel C [numSamples, overflow, chA, chB] = invoke(rapidBlockGroupObj, 'getRapidBlockData', numCaptures, ... downsamplingRatio, downsamplingRatioMode);
runBlock:- Collecting block of data: Timebase: 4 Pre-trigger samples: 2048 Post-trigger samples: 2048 runBlock: Waiting for device to become ready... runBlock: Device ready. getRapidBlockData: Setting up data buffers... getRapidBlockData: Retrieving data... getRapidBlockData: Converting to millivolts and assigning to channel array. getRapidBlockData: Data succesfully retrieved.
Obtain the number of captures
[status.getNoOfCaptures, numCaptures] = invoke(rapidBlockGroupObj, 'ps5000aGetNoOfCaptures');
Process data
Plot data values.
Calculate the time period over which samples were taken for each waveform. Use the timeIntNs output from the ps5000aGetTimebase2() function or calculate the sampling interval using the main Programmer's Guide. Take into account the downsampling ratio used.
timeNs = double(timeIntervalNanoseconds) * downsamplingRatio * double(0:numSamples - 1); % Channel A figure1 = figure('Name','PicoScope 5000 Series (A API) Example - Rapid Block Mode Capture', ... 'NumberTitle', 'off'); plot(timeNs, chA); title('Channel A'); xlabel('Time (ns)'); ylabel('Voltage (mV)'); grid on; movegui(figure1, 'west'); % Channel B figure2 = figure('Name','PicoScope 5000 Series (A API) Example - Rapid Block Mode Capture', ... 'NumberTitle', 'off'); plot(timeNs, chB); title('Channel B - Rapid Block Capture'); xlabel('Time (ns)'); ylabel('Voltage (mV)') grid on; movegui(figure2, 'east');


Stop the device
[status.stop] = invoke(ps5000aDeviceObj, 'ps5000aStop');
Disconnect device
Disconnect device object from hardware.
disconnect(ps5000aDeviceObj); delete(ps5000aDeviceObj);
Connection to PicoScope 5444D with serial number FY984/0005 closed successfully. Libraries unloaded successfully.