topic Re: Using Simulate Arbitrary Signal in LabVIEW

Re: Using Simulate Arbitrary Signal

duyngoc_0820 — Thu, 18 Jul 2019 04:30:57 GMT

Hello

I am a graduate student from Korea

I tried to import the below .lvm file by using the block "simulate arbitrary signal" but it could not load, and it seems Labview program is stopped working. Any body can check it for me?

Re: simulate arbitrary signal VI

duyngoc_0820 — Thu, 18 Jul 2019 02:38:40 GMT

Hello every one

I try to replace the existing signal in the block " simulate arbitrary signal" by the signal on the right hand side. However, I could not load it. It seems Labview is stopped working. Did I do something wrong?

Re: Using Simulate Arbitrary Signal

duyngoc_0820 — Thu, 18 Jul 2019 04:33:34 GMT

the lvm file

Re: Using Simulate Arbitrary Signal

GerdW — Thu, 18 Jul 2019 06:32:54 GMT

Hi duyngoc,

I don't know what you have tried in your VI but simply picking that ReadMeasurementData ExpressVI with its default settings results in this graph:

Note: Please keep your related questions in just one thread. It doesn't help to spread your messages in several (partly unrelated) threads.

Re: Using Simulate Arbitrary Signal

duyngoc_0820 — Thu, 18 Jul 2019 06:48:30 GMT

Dear Sir

Thank you for your kind comment

I have already tried using Read Measurement Data Express VI but as you can see I dont know why the X axis is 5000. I know that it relates to 5000 point data but how can I change 5000 to 5 as displayed with Simulate Arb. signal block. This is reason I decied to used the Simulate Arb. signal block even though it is not work well. Plus, I dont understand why there is a white line when I use the Read Measurement Data Express VI block. Does it affect anything if I use this signal as an excitation signal?

Re: Using Simulate Arbitrary Signal

GerdW — Thu, 18 Jul 2019 07:16:38 GMT

Hi duyngoc,

I dont know why the X axis is 5000. I know that it relates to 5000 point data

I used the default settings, which reads the first column as additional signal. YOu may try to change the ExpressVI settings to use it as time column…

but how can I change 5000 to 5 as displayed with Simulate Arb. signal block.

You may simply divide the data by 1000 to scale from 5000 to 5…

Plus, I dont understand why there is a white line when I use the Read Measurement Data Express VI block. Does it affect anything if I use this signal as an excitation signal?

Again: default settings of that ExpressVI.

You can always use SplitSignal to use only the 2nd signal in the DDT wire…

Generic suggestion: I would try to stay away from ExpressVIs as much as possible. It will improve your code in the end…

Re: Using Simulate Arbitrary Signal

duyngoc_0820 — Thu, 18 Jul 2019 07:37:52 GMT

As you can see in the attached file, I set the option for the Read Measurement Data Express VI block like that and get nice result. I realized that in the original .lvm file, there is text that is wrrited from the Write Measurement Data Express VI block which is only recognized when use with the "simulate Arb. signal" block. So, if I delete all text in the lvm file that I uploaded here, I get the result as shown the figure.

Re: Using Simulate Arbitrary Signal

duyngoc_0820 — Thu, 18 Jul 2019 07:49:20 GMT

I wonder that when I use the Arbitrary Signal Express VI block, I can use option "X value repeat" and " Entire signal each iteration". I wonder can I get a continous excitation signal from data which has only 5 seconds? It means that I want to repeatly get the excitation signal after each 5 seconds

Re: Using Simulate Arbitrary Signal

GerdW — Thu, 18 Jul 2019 07:59:04 GMT

Hi duyngoc,

you can get anything you want - that process is called "programming"!

When you want to repeat the signalafter 5s then you should use a loop…

Did you know you can "open the frontpanel" of ExpressVIs to get a peek behind their curtain?

Re: Using Simulate Arbitrary Signal

duyngoc_0820 — Thu, 18 Jul 2019 08:13:52 GMT

Thank you very much for your comment. Of course, I tried to use the for loop but it happen error. And I am new person in this field, so I dont know much about Labview. If you have time, please help me

Re: Using Simulate Arbitrary Signal

GerdW — Thu, 18 Jul 2019 08:21:00 GMT

Hi duyngoc,

please help me

Until now you didn't attach any VI.

How should we help to improve your code when you hesitate to attach that code?

(I prefer LV2017…)

Re: Using Simulate Arbitrary Signal

duyngoc_0820 — Thu, 18 Jul 2019 08:48:06 GMT

Dear Sir

I am sorry for that. As I attached the figure, I just think that it is very simple so I did not attach the VI program here

Below is the VI program and the .lvm data as my excitation signal. Please help me or give me suggestion

Thank you very much

Re: Using Simulate Arbitrary Signal

GerdW — Thu, 18 Jul 2019 09:17:52 GMT

Hi duyngoc,

your VI already outputs the very same signal each 50ms to the graph.

What else do you need?

When you want to see it on your frontpanel you could try this:

Note: I replaced the graph by a chart…

Re: Using Simulate Arbitrary Signal

duyngoc_0820 — Fri, 19 Jul 2019 01:17:03 GMT

Thank you very much

But which option did you choose in the "Configure Convert from Dynamic Data" block? I chose "1D array of scalars-automatic" but I did not get the result I need. Could u kindly attach the code here? I use LV2014 version now

Re: Using Simulate Arbitrary Signal

duyngoc_0820 — Fri, 19 Jul 2019 03:06:58 GMT

After adding "Configure Convert from Dynamic Data" block and Write Measurement Data Express VI, I checked the data obtain for each iteration. I realized that the data I got is from 0 second to 5 second for each iteration. But the one I want is time is continuously go as 0 second to infinity and only Y value can be repeatedly obtained from the original data. Is there any method to do this?

Re: Using Simulate Arbitrary Signal

GerdW — Fri, 19 Jul 2019 05:24:23 GMT

Hi duyngoc,

I realized that the data I got is from 0 second to 5 second for each iteration.

Yes, the data in your file lasts for 5s.

But the one I want is time is continuously go as 0 second to infinity and only Y value can be repeatedly obtained from the original data.

This is what my last snippet does: repeat those Y data obtained from original data…

Re: Using Simulate Arbitrary Signal

duyngoc_0820 — Fri, 19 Jul 2019 07:33:38 GMT

How can I repeat only Y column data obtained from my original data?

Re: Using Simulate Arbitrary Signal

GerdW — Fri, 19 Jul 2019 07:35:48 GMT

Hi duyngoc,

use a loop as shown above…

Re: Using Simulate Arbitrary Signal

duyngoc_0820 — Fri, 19 Jul 2019 07:48:17 GMT

I used the loop as shown in the above but I dont know how to set the condition in the Read Measurement Data block and Configure Convert from Dynamic data block. Could you let me know how to choose the option in there?

Re: Using Simulate Arbitrary Signal

GerdW — Fri, 19 Jul 2019 07:51:33 GMT

Hi duyngoc,

how to set the condition in the Read Measurement Data block

The same as you used before to read just that signal…

and Configure Convert from Dynamic data block.

Convert DDT to 1D array of scalars.