PicoScope 5000 Series (A API) Instrument Driver Oscilloscope Block Data Capture With Two Oscilloscopes 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_Block_2_Scope_Example, at the MATLAB command prompt.

The file, PS5000A_ID_BLOCK_2_SCOPE_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_Block_2_Scope_Example;

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

See also: icdevice | invoke

Suggested input test signals
Clear command window and close any figures
Load configuration information
Device connection
Set channels
Set device resolution
GET TIMEBASE
Set simple trigger
Set block parameters and capture data
Process data
Stop devices
Disconnect device

Suggested input test signals

This example was published using the following test signals:

Scope 1:- Channel A: 4 Vpp, 1 kHz sine wave
Scope 2:- Channel A: 4 Vpp, 1 kHz square wave

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('ps5000aDeviceObj1', 'var') && ps5000aDeviceObj1.isvalid && strcmp(ps5000aDeviceObj1.status, 'open'))

    openDevice = questionDialog(['Device object ps5000aDeviceObj1 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(ps5000aDeviceObj1);
        delete(ps5000aDeviceObj1);

    else

        % Exit script if User selects 'No'.
        return;

    end

end

if (exist('ps5000aDeviceObj2', 'var') && ps5000aDeviceObj2.isvalid && strcmp(ps5000aDeviceObj2.status, 'open'))

    openDevice = questionDialog(['Device object ps5000aDeviceObj2 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(ps5000aDeviceObj2);
        delete(ps5000aDeviceObj2);

    else

        % Exit script if User selects 'No'.
        return;

    end

end

% Create a device object - provide the serial number as a second argument if required.
ps5000aDeviceObj1 = icdevice('picotech_ps5000a_generic.mdd', '');
ps5000aDeviceObj2 = icdevice('picotech_ps5000a_generic.mdd', '');

% Connect device object to hardware.
connect(ps5000aDeviceObj1);
connect(ps5000aDeviceObj2);

PicoScope 5000 Series (A API) MATLAB Instrument Driver


Copyright © 2013-2018 Pico Technology Ltd. All rights reserved.

Number of units found: 2

Serial number(s): CQ178/005,FY984/0005

PicoScope 5000 Series (A API) MATLAB Instrument Driver


Copyright © 2013-2018 Pico Technology Ltd. All rights reserved.

Number of units found: 2

Serial number(s): CQ178/005,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

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: 5244A
       Batch/Serial Number: CQ178/005
               USB Version: 2.0
           Analog Channels: 2
                Resolution: 8 bits
                 Bandwidth: 200 MHz
             Buffer Memory: 256 MS
     Maximum Sampling Rate: 1 GS/s
     Signal Generator Type: Function Generator

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 used - use the ps5000aSetChannel() function to turn channels on or off and set voltage ranges, coupling, as well as analogue offset.

Set device resolution

% Max. resolution with 2 channels enabled is 15 bits.
[status1.setResolution, scope1.resolution] = invoke(ps5000aDeviceObj1, 'ps5000aSetDeviceResolution', 15);
[status2.setResolution2, scope2.resolution] = invoke(ps5000aDeviceObj2, 'ps5000aSetDeviceResolution', 8);

ps5000aSetDeviceResolution: Device resolution set to 15 bits.

ps5000aSetDeviceResolution: Device resolution set to 8 bits.

GET TIMEBASE

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

scope1.timebaseIndex = 65;

status1.getTimebase = PicoStatus.PICO_INVALID_TIMEBASE;

while (status1.getTimebase == PicoStatus.PICO_INVALID_TIMEBASE)

    [status1.getTimebase, scope1.timeIntervalNanoSeconds, scope1.maxSamples] = invoke(ps5000aDeviceObj1, 'ps5000aGetTimebase', scope1.timebaseIndex, 0);

    if (status1.getTimebase == PicoStatus.PICO_OK)

        break;

    else

        scope1.timebaseIndex = scope1.timebaseIndex + 1;

    end

end

set(ps5000aDeviceObj1, 'timebase', scope1.timebaseIndex);

% Repeat for second device

scope2.timebaseIndex = 65;

status2.getTimebase = PicoStatus.PICO_INVALID_TIMEBASE;

while (status2.getTimebase == PicoStatus.PICO_INVALID_TIMEBASE)

    [status2.getTimebase, scope2.timeIntervalNanoSeconds, scope2.maxSamples] = invoke(ps5000aDeviceObj2, 'ps5000aGetTimebase', scope2.timebaseIndex, 0);

    if (status2.getTimebase == PicoStatus.PICO_OK)

        break;

    else

        scope2.timebaseIndex = scope2.timebaseIndex + 1;

    end

end

set(ps5000aDeviceObj2, 'timebase', scope2.timebaseIndex);

Set simple trigger

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

% Trigger properties and functions are located in the Instrument
% Driver's Trigger group.

triggerGroupObj1 = get(ps5000aDeviceObj1, 'Trigger');
triggerGroupObj1 = triggerGroupObj1(1);

triggerGroupObj2 = get(ps5000aDeviceObj2, 'Trigger');
triggerGroupObj2 = triggerGroupObj2(1);

% Set the |autoTriggerMs| property in order to automatically trigger the
% oscilloscope after 2 seconds if a trigger event has not occurred. Set to 0
% to wait indefinitely for a trigger event.

set(triggerGroupObj1, 'autoTriggerMs', 2000);
set(triggerGroupObj2, 'autoTriggerMs', 2000);

% Channel     : 0 (ps5000aEnuminfo.enPS5000AChannel.PS5000A_CHANNEL_A)
% Threshold   : 1000 mV on device 1, 500 mV on device 2
% Direction   : 2 (ps5000aEnuminfo.enPS5000AThresholdDirection.PS5000A_RISING)

[status1.setSimpleTrigger] = invoke(triggerGroupObj1, 'setSimpleTrigger', 0, 1000, 2);
[status2.setSimpleTrigger] = invoke(triggerGroupObj2, 'setSimpleTrigger', 0, 500, 2);

Set block parameters and capture data

Capture a block of data and retrieve data values for all enabled analog channels.

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

blockGroupObj1 = get(ps5000aDeviceObj1, 'Block');
blockGroupObj1 = blockGroupObj1(1);

blockGroupObj2 = get(ps5000aDeviceObj2, 'Block');
blockGroupObj2 = blockGroupObj2(1);

% Set pre-trigger and post-trigger samples.
set(ps5000aDeviceObj1, 'numPreTriggerSamples', 1024);
set(ps5000aDeviceObj1, 'numPostTriggerSamples', 2048);

set(ps5000aDeviceObj2, 'numPreTriggerSamples', 2048);
set(ps5000aDeviceObj2, 'numPostTriggerSamples', 4096);

% Start the devices collecting data

% Capture a block of data:
%
% segment index: 0

status1.ps5000aRunBlock = invoke(blockGroupObj1, 'ps5000aRunBlock', 0);
status2.ps5000aRunBlock = invoke(blockGroupObj2, 'ps5000aRunBlock', 0);

% Poll the device driver to see if data is available

scope1.ready = PicoConstants.FALSE;
scope2.ready = PicoConstants.FALSE;

while (scope1.ready == PicoConstants.FALSE || scope2.ready == PicoConstants.FALSE)

    [status1.ready, scope1.ready] = invoke(blockGroupObj1, 'ps5000aIsReady');
    [status2.ready, scope2.ready] = invoke(blockGroupObj2, 'ps5000aIsReady');

    pause(0.01);

end


% Retrieve data values:

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

[scope1.numSamples, scope1.overflow, scope1.chA, scope1.chB, scope1.chC, scope1.chD] = invoke(blockGroupObj1, 'getBlockData', startIndex, segmentIndex, ...
                                                                                            downsamplingRatio, downsamplingRatioMode);

[scope2.numSamples, scope2.overflow, scope2.chA, scope2.chB, scope2.chC, scope2.chD] = invoke(blockGroupObj2, 'getBlockData', startIndex, segmentIndex, ...
                                                                                            downsamplingRatio, downsamplingRatioMode);

ps5000aRunBlock:- Collecting block of data:
	Timebase: 65
	Pre-trigger samples: 1024
	Post-trigger samples: 2048

ps5000aRunBlock:- Collecting block of data:
	Timebase: 65
	Pre-trigger samples: 2048
	Post-trigger samples: 4096

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

getBlockData: Setting up data buffers...
getBlockData: Retrieving data...
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 a Figure.

scope1.figureName = ['PicoScope ', ps5000aDeviceObj1.InstrumentModel, ' (', get(ps5000aDeviceObj1, 'unitSerial'), ') Block Capture'];
scope1.figure = figure('Name', scope1.figureName, ...
    'NumberTitle','off');

% 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.

scope1.timeNs = double(scope1.timeIntervalNanoSeconds) * downsamplingRatio * double(0:scope1.numSamples - 1);
scope1.timeMs = scope1.timeNs / 1e6;

% Channel A
plot(scope1.timeMs, scope1.chA, 'b');
title('Channel A');
xlabel('Time (ms)');
ylabel('Voltage (mV)');
grid('on');

movegui(scope1.figure, 'west');

scope2.figureName = ['PicoScope ', ps5000aDeviceObj2.InstrumentModel, ' (', get(ps5000aDeviceObj2, 'unitSerial'), ') Block Capture'];
scope2.figure = figure('Name', scope2.figureName, ...
    'NumberTitle','off');

% 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.

scope2.timeNs = double(scope2.timeIntervalNanoSeconds) * downsamplingRatio * double(0:scope2.numSamples - 1);
scope2.timeMs = scope2.timeNs / 1e6;

% Channel A
plot(scope2.timeMs, scope2.chA, 'b');
title('Channel A');
xlabel('Time (ms)');
ylabel('Voltage (mV)');
grid('on');

movegui(scope2.figure, 'east');

Stop devices

[status1.stop] = invoke(ps5000aDeviceObj1, 'ps5000aStop');
[status2.stop] = invoke(ps5000aDeviceObj2, 'ps5000aStop');

Disconnect device

Disconnect device object from hardware.

disconnect(ps5000aDeviceObj1);
delete(ps5000aDeviceObj1);

disconnect(ps5000aDeviceObj2);
delete(ps5000aDeviceObj2);

Connection to PicoScope 5244A with serial number CQ178/005 closed successfully.
Other PicoScope 5000 Series (A API) devices are still connected - libraries will not be unloaded.
Connection to PicoScope 5444D with serial number FY984/0005 closed successfully.
Libraries unloaded successfully.