PicoScope 6000 Series Instrument Driver 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, PS6000_ID_Block_Example, at the MATLAB command prompt.

The file, PS6000_ID_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: PS6000_ID_Block_Example;

Description: Demonstrates how to set properties and call functions in order to capture a block of data from a PicoScope 6000 Series Oscilloscope.

See also: icdevice | invoke

Copyright: © 2014 - 2017 Pico Technology Ltd. See LICENSE file for terms.

Contents

Suggested Input Test Signal

This example was published using the following test signal:

Clear Command Window and Close any Figures

clc;
close all;

Load Configuration Information

PS6000Config;

Device Connection

% Check if an Instrument session using the device object 'ps6000DeviceObj'
% is still open, and if so, disconnect if the User chooses 'Yes' when prompted.
if (exist('ps6000DeviceObj', 'var') && ps6000DeviceObj.isvalid && strcmp(ps6000DeviceObj.status, 'open'))

    openDevice = questionDialog(['Device object ps6000DeviceObj 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(ps6000DeviceObj);
        delete(ps6000DeviceObj);

    else

        % Exit script if User selects 'No'
        return;

    end

end

% Create a device object.
% The serial number can be specified as a second input parameter.
ps6000DeviceObj = icdevice('picotech_ps6000_generic.mdd', '');

% Connect device object to hardware.
connect(ps6000DeviceObj);

% Set device property to hide display output during data collection.
set(ps6000DeviceObj, 'displayOutput', PicoConstants.FALSE);

Copyright © 2014 - 2017 Pico Technology Ltd. All rights reserved.

PicoScope 6000 Series MATLAB Instrument Driver

Number of units found: 1

Serial number(s): EW421/006

Opening PicoScope 6000 Series device...

   Instrument Device Object Using Driver : picotech_ps6000_generic.mdd
 
   Instrument Information
      Type:               Oscilloscope
      Manufacturer:       Pico Technology Ltd.
      Model:              PicoScope 6000 Series
 
   Driver Information
      DriverType:         MATLAB generic
      DriverName:         picotech_ps6000_generic.mdd
      DriverVersion:      1.2.20
 
   Communication State
      Status:             open

Setting Device Parameters...

Default Channel Setup:-
-----------------------

ChannelA:-
	Enabled: True
	Coupling: DC
	Range:5V
	Analogue Offset: 0.0 V
	Bandwidth: Full

ChannelB:-
	Enabled: True
	Coupling: DC
	Range:5V
	Analogue Offset: 0.0 V
	Bandwidth: Full

ChannelC:-
	Enabled: True
	Coupling: DC
	Range:5V
	Analogue Offset: 0.0 V
	Bandwidth: Full

ChannelD:-
	Enabled: True
	Coupling: DC
	Range:5V
	Analogue Offset: 0.0 V
	Bandwidth: Full

Turning off Equivalent Time Sampling...
Turning off trigger...

Default Block mode parameters:-

               Timebase index : 161
                 Time Interval: 1004.8 ns
 Number of pre-trigger samples: 0
Number of post-trigger samples: 1000000
       Total number of samples: 1000000

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
       Offset voltage: 0 mV
 Peak to Peak voltage: 2000 mV

Initialisation complete.

Connected to PicoScope 6000 Series device:-

      Instrument Model: 6404D
   Batch/Serial Number: EW421/006
     Analogue Channels: 4
             Bandwidth: 500 MHz
         Buffer memory: 2048 MS
 Maximum sampling rate: 5 GS/s
 Signal Generator Type: Arbitrary Waveform Generator

Set Channels

% Default driver settings applied to channels are listed below -
% use ps6000SetChannel to turn channels on or off and set voltage ranges,
% coupling, as well as analogue offset.

% In this example, data is only collected on Channel A so default settings
% are used and Channels B, C and D are switched off.

% Channels       : 1 - 3 (ps6000Enuminfo.enPS6000Channel.PS6000_CHANNEL_B - PS6000_CHANNEL_D)
% Enabled        : 0 (off)
% Type           : 1 (ps6000Enuminfo.enPS6000Coupling.PS6000_DC_1M)
% Range          : 3 (ps6000Enuminfo.enPS6000Range.PS6000_100MV) for the PicoScope 6407 or
%                  8 (ps6000Enuminfo.enPS6000Range.PS6000_5V) for all other PicoScope 6000 Series models
% Analogue Offset: 0.0
% Bandwidth      : 0 (ps6000Enuminfo.enPS6000BandwidthLimiter.PS6000_BW_FULL)

% Select the correct voltage range and coupling to use

voltageRangeIndex = ps6000Enuminfo.enPS6000Range.PS6000_5V;
coupling          = ps6000Enuminfo.enPS6000Coupling.PS6000_DC_1M;

if (strcmp(ps6000DeviceObj.InstrumentModel, PS6000Constants.MODEL_PS6407))

    voltageRangeIndex = ps6000Enuminfo.enPS6000Range.PS6000_100MV;
    coupling          = ps6000Enuminfo.enPS6000Coupling.PS6000_DC_50R;

end

% Execute device object function(s).
[status.setChB] = invoke(ps6000DeviceObj, 'ps6000SetChannel', 1, 0, coupling, voltageRangeIndex, 0.0, 0);
[status.setChC] = invoke(ps6000DeviceObj, 'ps6000SetChannel', 2, 0, coupling, voltageRangeIndex, 0.0, 0);
[status.setChD] = invoke(ps6000DeviceObj, 'ps6000SetChannel', 3, 0, coupling, voltageRangeIndex, 0.0, 0);

Verify Timebase Index and Maximum Number of Samples

Driver default timebase index used - use ps6000GetTimebase2 to query the driver as to suitability of using a particular timebase index and the maximum number of samples available in the segment selected (the buffer memory has not been segmented in this example) then set the 'timebase' property if required.

To use the fastest sampling interval possible, set one analogue 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 161 is valid.

% Initial call to ps6000GetTimebase2 with parameters:
% timebase      : 161
% segment index : 0

status.getTimebase2 = PicoStatus.PICO_INVALID_TIMEBASE;
timebaseIndex       = get(ps6000DeviceObj, 'timebase');

while (status.getTimebase2 == PicoStatus.PICO_INVALID_TIMEBASE)

	[status.getTimebase2, timeIntervalNanoSeconds, maxSamples] = invoke(ps6000DeviceObj, 'ps6000GetTimebase2', timebaseIndex, 0);

    if (status.getTimebase2 == PicoStatus.PICO_OK)

        break;

    else

        timebaseIndex = timebaseIndex + 1;

    end

end

set(ps6000DeviceObj, 'timebase', timebaseIndex);

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(ps6000DeviceObj, '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 (ps6000Enuminfo.enPS6000Channel.PS6000_CHANNEL_A)
% Threshold   : 50 mV (for the PicoScope 6407) or 500 mV otherwise
% Direction   : 2 (ps6000Enuminfo.enPS6000ThresholdDirection.PS6000_RISING)

thresholdVoltage = 500;

if (strcmp(ps6000DeviceObj.InstrumentModel, PS6000Constants.MODEL_PS6407))

    thresholdVoltage = 50;

end

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

Set Block Parameters and Capture Data

Capture a block of data and retrieve data values for Channel A.

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

blockGroupObj = get(ps6000DeviceObj, '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 ps6000GetTimebase2.
% The default of 0 pre-trigger and 1 million post-trigger samples is used
% in this example.

% set(ps6000DeviceObj, 'numPreTriggerSamples', 0);
% set(ps6000DeviceObj, 'numPostTriggerSamples', 2e6);

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 ps6000RunBlock function and poll the ps6000IsReady 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:
%
% start index       : 0
% segment index     : 0
% downsampling ratio: 1
% downsampling mode : 0 (ps6000Enuminfo.enPS6000RatioMode.PS6000_RATIO_MODE_NONE)

% Provide additional output arguments for the remaining channels e.g. chB
% for Channel B.
[numSamples, overflow, chA, ~, ~, ~] = invoke(blockGroupObj, 'getBlockData', 0, 0, 1, 0);

% Stop the device
[status.stop] = invoke(ps6000DeviceObj, 'ps6000Stop');

Process Data

Plot data values returned from the device.

figure1 = figure('Name','PicoScope 6000 Series Example - Block Mode Capture', ...
    'NumberTitle', 'off');

% Calculate sampling interval (nanoseconds) and convert to milliseconds.
% Use the timeIntervalNanoSeconds output from the ps4000aGetTimebase2
% function or calculate it using the main Programmer's Guide.

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

% Channel A
plot(timeMs, chA);

title('Block Data Acquisition');
xlabel('Time (ms)');
ylabel('Voltage (mV)');

grid on;
legend('Channel A');

Disconnect Device

Disconnect device object from hardware.

disconnect(ps6000DeviceObj);
delete(ps6000DeviceObj);

Connection to PicoScope 6404D with serial number EW421/006 closed successfully.
Libraries unloaded successfully.


Published with MATLAB® R2017a