PicoScope 5000 Series (A API) Instrument Driver Mixed Signal Oscilloscope 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:

  1. Create a device object
  2. Connect to the instrument
  3. Configure properties
  4. Invoke functions
  5. Disconnect from the instrument

To run the instrument control session, type the name of the file, PS5000A_ID_MSO_Block_Example, at the MATLAB command prompt.

The file, PS5000A_ID_MSO_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_MSO_Block_Example;

Description: Demonstrates how to call functions in order to capture a block of data from a PicoScope 5000 Series Mixed Signal Oscilloscope using the underlying 'A' API library functions.

See also: icdevice | invoke

Copyright: © 2018 Pico Technology Ltd. See LICENSE file for terms.

Contents

Suggested input test signals

This example was published using the following test signals:

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): FY971/0003

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

Default Digital Port Setup:-
----------------------------

PORT0:-
	Enabled: True
	Logic Level: +1.5 V

PORT1:-
	Enabled: True
	Logic Level: +1.5 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: 5444DMSO
       Batch/Serial Number: FY971/0003
               USB Version: 3.0
           Analog Channels: 4
          Digital Channels: 16
                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 analog channels and digital ports

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, as well as
% Digital Port 0 channels (D0 - D7). If it is a 4-channel model, channels C
% and D will be switched off if the power supply is connected. Digital Port
% 1 (D8 - D15) is switched off.

% 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

Use the ps5000aSetDigitalPort() function to enable/disable digital ports and set the logic level threshold. This function is located in the Instrument Driver's Digital Group. Enabling a digital port will enable all channels on that port, while setting the enabled parameter to 0 will turn off all digital channels on that port.

digitalObj = get(ps5000aDeviceObj, 'Digital');

% Digital Port  : 128 (ps5000aEnuminfo.enPS5000AChannel.PS5000A_DIGITAL_PORT0)
% Enabled       : 1 (On - PicoConstants.TRUE)
% Logic Level   : 1.5 V

status.setDPort0 = invoke(digitalObj, 'ps5000aSetDigitalPort', ps5000aEnuminfo.enPS5000AChannel.PS5000A_DIGITAL_PORT0, 1, 1.5);

% Digital Port  : 129 (ps5000aEnuminfo.enPS5000AChannel.PS5000A_DIGITAL_PORT1)
% Enabled       : 0 (Off - PicoConstants.FALSE)
% Logic Level   : 0 V

status.setDPort1 = invoke(digitalObj, 'ps5000aSetDigitalPort', ps5000aEnuminfo.enPS5000AChannel.PS5000A_DIGITAL_PORT1, 0, 0);

Set device resolution

% Max. resolution with 2 channels enabled is 15 bits.
[status.setResolution, resolution] = invoke(ps5000aDeviceObj, 'ps5000aSetDeviceResolution', 15);
ps5000aSetDeviceResolution: Device resolution set to 15 bits.

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 65 is valid.

% Initial call to ps5000aGetTimebase2() with parameters:
%
% timebase      : 65
% segment index : 0

status.getTimebase2 = PicoStatus.PICO_INVALID_TIMEBASE;
timebaseIndex = 65;

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: 65, sampling interval: 504 ns

Set simple trigger

Set a trigger on channel A, with an auto timeout - the default value for delay is used.

% 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   : 1000 mV
% Direction   : 2 (ps5000aEnuminfo.enPS5000AThresholdDirection.PS5000A_RISING)

[status.setSimpleTrigger] = invoke(triggerGroupObj, 'setSimpleTrigger', 0, 1000, 2);

Set block parameters and capture data

Capture a block of data and retrieve data values for channels A and B.

% Block data acquisition properties and functions are located in the
% Instrument Driver's Block group.

blockGroupObj = get(ps5000aDeviceObj, 'Block');
blockGroupObj = blockGroupObj(1);

% Set pre-trigger and post-trigger samples as required - the total of this
% should not exceed the value of |maxSamples| returned from the call to
% |ps5000aGetTimebase2()|. The number of pre-trigger samples is set in this
% example but default of 10000 post-trigger samples is used.

% Set pre-trigger samples.
set(ps5000aDeviceObj, 'numPreTriggerSamples', 1024);

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.

% Capture a block of data:
%
% segment index: 0 (The buffer memory is not segmented in this example)

[status.runBlock] = invoke(blockGroupObj, 'runBlock', 0);

% Retrieve data values:

startIndex              = 0;
segmentIndex            = 0;
downsamplingRatio       = 1;
downsamplingRatioMode   = ps5000aEnuminfo.enPS5000ARatioMode.PS5000A_RATIO_MODE_NONE;

% Provide additional output arguments for other channels e.g. chC for
% channel C if using a 4-channel PicoScope.
[numSamples, overflow, chA, chB, ~, ~, dPort0, ~] = invoke(blockGroupObj, 'getBlockData', startIndex, segmentIndex, ...
                                                        downsamplingRatio, downsamplingRatioMode);
runBlock:- Collecting block of data:
	Timebase: 65
	Pre-trigger samples: 1024
	Post-trigger samples: 10000

runBlock: Waiting for device to become ready...
runBlock: Device ready.

getBlockData: Setting up data buffers...
getBlockData: Retrieving data...
getBlockData: Assigning digital data to port array.
getBlockData: Assigning analog data to array and converting to millivolts.
getBlockData: Data succesfully retrieved.

Process data

In this example the data values returned from the device are displayed in plots in with separate figures for analog and digital data.

Calculate time (nanoseconds) and convert to milliseconds Use timeIntervalNanoseconds output from the ps5000aGetTimebase2() function or calculate it using the main Programmer's Guide. Take into account the downsampling ratio used.

timeNs = double(timeIntervalNanoseconds) * downsamplingRatio * double(0:numSamples - 1);
timeMs = timeNs / 1e6;

Analog data

scrsz = get(groot,'ScreenSize');

analogFigure = figure('Name','PicoScope 5000 Series (A API) - MSO Block Mode Capture', ...
    'NumberTitle', 'off', 'Position', [1 scrsz(4)/4 scrsz(3)/2 scrsz(4)/2]);

movegui(analogFigure, 'west');

hold on;

% Channels A and B.
plot(timeMs, chA, timeMs, chB);
title('Analog Channel Data');
xlabel('Time (ms)');
ylabel('Voltage (mV)');
legend('Channel A', 'Channel B');
grid on;

hold off;

Digital data

digitalFigure = figure('Name','PicoScope 5000 Series (A API) Example - MSO Block Mode Capture', ...
    'NumberTitle', 'off', 'Position', [scrsz(3)/2 + 1 scrsz(4)/4 scrsz(3)/2 scrsz(4)/2]);

movegui(digitalFigure, 'east');

disp('Converting digital integer data to binary...');

% Create 2D array to hold binary data values for each channel.
dPort0Binary = zeros(numSamples, 8);

% Retrieve the bit values from the lower 8 bits of the 16-bit values
% returned for dPort0 - each bit corresponds to a digital channel. Channel
% D0 data will be in column 8 and D7 data will be in column 1.
for sample = 1:numSamples

    dPort0Binary(sample, :) = bitget(dPort0(sample), 8:-1:1, 'int16');

end

hold on;

% Specify colors to use for the plots - the colour to use will be selected
% according to the digital channel.
digiPlotColours = ['m', 'b', 'r', 'g'];

% Display digital data in a 4 x 2 grid
for i = 1:8

    subplot(4, 2, i);
    plot(timeMs, dPort0Binary(:, (8 - (i - 1))), digiPlotColours(rem(i, length(digiPlotColours)) + 1));
    title(strcat('Digital Channel D', num2str(i - 1)));
    xlabel('Time (ms)');
    ylabel('Logic Level');
    axis([-inf, inf, -0.5, 1.5])
    grid on;

end

hold off;
Converting digital integer data to binary...

Stop the device

[status.stop] = invoke(ps5000aDeviceObj, 'ps5000aStop');

Disconnect device

Disconnect device object from hardware.

disconnect(ps5000aDeviceObj);
delete(ps5000aDeviceObj);
Connection to PicoScope 5444DMSO with serial number FY971/0003 closed successfully.
Libraries unloaded successfully.