AnsweredAssumed Answered

89601B dotNet C Code + MATLAB question

Question asked by jgilbert on Aug 15, 2011
Latest reply on Nov 11, 2011 by LittleRocket

Like • Show 0 Likes0
Comment • 12

Im running into a problem understanding the structure of some of the .NET code assemblies. I am able to set the software using the DigitalDemod MeasurementExtension, and getting all my trace windows aligned correct, but when I get into change the MeasurementExtension I am running into a problem understanding how the abstract classes between the DigitalDemod Assembly and the Vsa Assembly are accessible, namely the Format Property. Is there a code sample showing the proper way to access the Format Property?

No one else has this question

Outcomes

12 Replies

Kleb Aug 15, 2011 8:08 PM
Mark Correct
Correct Answer
Hi jgilbert,

Here's some sample code to set the Format parameter for DigDemod:

DigitalDemod.MeasurementExtension digDemod = app.Measurements.SelectedItem.GetMeasurementExtension<DigitalDemod.MeasurementExtension>();
digDemod.Format = DigitalDemod.Format.OffsetQpsk;

Also, you can easily see the C# code to set a UI parameter if you open the Output window (Window > Output and select the Show Code check box). Each time you change a setting on the user interface, the corresponding command is echoed to the Output window.

Hope this helps,
Caleb
Like • Show 0 Likes0
Actions
jgilbert Aug 17, 2011 4:53 AM
Mark Correct
Correct Answer
Caleb,

Awesome, its worked perfectly and thanks much for the tip on the Output display that is exactly what I needed.

~J
Like • Show 0 Likes0
Actions
Kleb Aug 17, 2011 8:07 AM
Mark Correct
Correct Answer
Glad I could help
Like • Show 0 Likes0
Actions
LittleRocket Nov 8, 2011 6:44 AM
Mark Correct
Correct Answer
Hi Kleb,
I have a Matlab code that run the VSA and extract baseband data for further processing. After the migration to 89600B, I'll have to re-write my code for the .NET API. Working off the sample measdemo.m, I have been able to configure it for Digital Demodulation with the following code:

vsaDemod = DigitalDemod.MeasurementExtension.ExtensionType();
demodModule = vsaMeas.SetMeasurementExtension(vsaDemod);

My next step is setting Modulation format to Offset QPSK. I'm not quite sure how to figure out the Matlab equipvalent of:

app.Measurements.SelectedItem.GetMeasurementExtension<DigitalDemod.MeasurementExtension>().Format = DigitalDemod.Format.OffsetQpsk;

I'd appreciate your help. Thanks.
Like • Show 0 Likes0
Actions
Kleb Nov 8, 2011 9:38 AM
Mark Correct
Correct Answer
Hi Little Rocket,

The .NET command you list there is setting the Format property on the current measurement extension, which is the DigitalDemod measurement extension object.

The line of code
demodModule = vsaMeas.SetMeasurementExtension(vsaDemod);

returns a handle to the measurement extension object so you should be able to just do
demodModule.Format = Agilent.SA.Vsa.DigitalDemod.Format.OffsetQpsk;

However, this won't quite work in Matlab as we recently found. Here is some documentation that will be in the .NET help for the next 89600 VSA release:

Variable type declaration
When getting a handle to the measurement extension for a particular measurement type, MATLAB will throw an error when you try to access the members of the handle. To work around this issue, use the following code and modify for the particular measurement type you are using:

...

% get handle to the measurement extension object for the demodulator
measExtensionType = Agilent.SA.Vsa.CustomOfdm.MeasurementExtension.ExtensionType;
genericHandle = vsaMeas.SetMeasurementExtension(measExtensionType);
measHandle = Agilent.SA.Vsa.CustomOfdm.MeasurementExtension.CastToExtensionType(genericHandle);

% MATLAB workaround
measHandle.delete;
genericHandle = vsaMeas.SetMeasurementExtension(measExtensionType);
measHandle = Agilent.SA.Vsa.CustomOfdm.MeasurementExtension.CastToExtensionType(genericHandle);

% proceed to set properties of the demod
measHandle.FftLength = 128;

...

Hope it works for you.
Like • Show 0 Likes0
Actions
LittleRocket Nov 9, 2011 7:50 AM
Mark Correct
Correct Answer
I'm a little confused:

In the Matlab workaround part, after deleting the measHandle, the following 2 lines are exactly the same as the upper part?

In my case, I'd need to replace CustomOfdm with DigitalDemod, correct?
Like • Show 0 Likes0
Actions
Kleb Nov 9, 2011 8:41 AM
Mark Correct
Correct Answer
Yes, you'd replace CustomOfdm with DigitalDemod.

Hmm, I can't test it at the moment, but now that I'm looking at the code, perhaps you could omit the line after measHandle.delete and it would still work. But, the way it was explained to me, the delete command gets Matlab to realize the correct type (DigitalDemod.MeasurementExtension, in your case) of the variable measHandle so that you can access the members specific to the demod's measurement extension class.
Like • Show 0 Likes0
Actions
LittleRocket Nov 9, 2011 6:31 PM
Mark Correct
Correct Answer
So here is my code segment:

% get handle to the measurement extension object for the demodulator
measExtensionType = Agilent.SA.Vsa.DigitalDemod.MeasurementExtension.ExtensionType;
genericHandle = vsaMeas.SetMeasurementExtension(measExtensionType);
measHandle = Agilent.SA.Vsa.DigitalDemod.MeasurementExtension.CastToExtensionType(genericHandle);

% MATLAB workaround
measHandle.delete;
genericHandle = vsaMeas.SetMeasurementExtension(measExtensionType);
measHandle = Agilent.SA.Vsa.DigitalDemod.MeasurementExtension.CastToExtensionType(genericHandle);

% proceed to set properties of the demod
%measHandle.FftLength = 128;
measHandle.Format = DigitalDemod.Format.OffsetQpsk;
measHandle.SymbolRate = 2500000;
measHandle.ResultLength = 2048;

Matlab complaints on the last three lines. Its error message:

Error using measdemo_new (line 88)
Message: Could not load type
'Agilent.SA.VsaComposition.ScopedExportAttribute' from
assembly 'Agilent.SA.Vsa.Interfaces, Version=14.20.164.0,
Culture=neutral, PublicKeyToken=a25294fa6a616d95'.
Source: mscorlib
HelpLink:
Like • Show 0 Likes0
Actions
Kleb Nov 10, 2011 10:48 AM
Mark Correct
Correct Answer
I talked to one of our R&D engineers and he thought perhaps it might work if you fully qualified the .NET path to the Format enum:
measHandle.Format = Agilent.SA.Vsa.DigitalDemod.Format.OffsetQpsk;

Alternatively, you could import the Vsa namespace before setting the format:
import Agilent.SA.Vsa.*
Like • Show 0 Likes0
Actions
LittleRocket Nov 10, 2011 6:37 PM
Mark Correct
Correct Answer
I've tried the fully qualification, still the same error message.(Also I've already had the import statement, along with another one for the DigitalDemod)
Like • Show 0 Likes0
Actions
Kleb Nov 11, 2011 8:14 AM
Mark Correct
Correct Answer
Hmm, what version of Matlab are you using?

I suppose a possiblity might be that your version does not fully support .NET 4.0 assemblies. Have you tried using the assemblies in the Interfaces_v3.5 folder?
Like • Show 0 Likes0
Actions
LittleRocket Nov 11, 2011 9:36 PM
Mark Correct
Correct Answer
I'm using Matlab R2011b. And yes, I'm using v3.5 interface.
Like • Show 0 Likes0
Actions

89601B dotNet C Code + MATLAB question

Outcomes

Related Content

Recommended Content