LV 2017 Possible bug with property node settings in edit mode

October 13, 2017, 8:29 am

≫ Next: Power spectrum VI and number of samples

≪ Previous: Error 1055 when trying to change attributes of a 3D picture

Please try to reproduce the following problem I just discovered. I did not check with other combinations, other control types and property types. First testing only this.

Open an empty VI. Drop a Tree Control into the FP. Go to BD, and via right click, create a Property node, set the first element to "KeyFocus". Right click again on this node, and set it "Change All to Write". Expand the property node to have a second element. The next element will apear from the list, which is "Label". This is in "Read mode" (not writable prop). Click on this, and change the property to "Edit Position". Here the bug comes! Somehow LabVIEW keeps this second element in "Read only" mode, there is no way you can change either both or this second entry to "Change All to Write"!
If you keep the the KeyFocus entry in "Read mode" from the beginning, there is no bug. You can expand to prop.node to have 2 entries, select EditPos for the second one, and THEN you can set each of them or both at once to "Write mode".

I think this is a bug...

EDIT: ok, maybe it is not a bug, but this is the way how it works. I realized, there is an option to change to write mode that individual entry. But still, after right click, it would be handy to change the entire propnode to Write mode using the first entry from the right click menu...

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Power spectrum VI and number of samples

October 13, 2017, 8:40 am

≫ Next: THD current

≪ Previous: LV 2017 Possible bug with property node settings in edit mode

Please look at the Help in the part where it is explained about the number of samples.

It is not clear to me what happens if the number of samples is not respecting what is said in the help.

That is I cannot understand if the results from Power Spectrum VI are reliable or not when the number of samples is not factorable as the product of small prime numbers.

Is it used zero padding or what? In the block diagram a library is called, so I cannot figure out what it is doing.

Thanks

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THD current

October 13, 2017, 8:55 am

≫ Next: MathScript RT node define and update variable without shift register?

≪ Previous: Power spectrum VI and number of samples

hello.

I have a problem, I dont know how calculate the THD of a current's signal.

The current signal is measured with an component of National instruments.

I am reading on the forum but i dont find what i search

There is somebody that know the problem and know a possible VI?

thank

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MathScript RT node define and update variable without shift register?

October 13, 2017, 9:20 am

≫ Next: Strings too long

≪ Previous: THD current

Is there a method for defining and updating a variable inside a MathScript RT node without using a shift register? Something like this except that it would actually run:

error after first iteration

I had a couple ideas but they didn't work:

Defining 'a' as global - can't use global on Real-Time system
Defining and saving 'a' outside this loop, then use load and save inside while loop - runs way too slow

The reason I don't want to use a shift register (like with variable 'i') is that the actual script will have a lot of arrays and variables. I'd like to avoid "mapping" the variables to the arrays in order to pass their values to the next iteration.

Any suggestions?

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Strings too long

October 13, 2017, 10:38 am

≫ Next: Can not find/download Tag Configuration Editor

≪ Previous: MathScript RT node define and update variable without shift register?

hi guys,

I'm having a problem with some strings, I'm sending larges pieces of code via string control, and in some point (I think near 180 characters) the code finish and only send a piece...

I dont know if there's a limit in the string or if is in the VISA Serial communication or what... but either way I want to know if this limit exists and if I can change it, or else I'll have to manipulate in some way the string to send it by lines or something.

Sorry for bad english, I hope that someone could understand me!

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Can not find/download Tag Configuration Editor

October 13, 2017, 11:16 am

≫ Next: first column of multicolumn listbox

≪ Previous: Strings too long

Hello all. I was trying to download the Tag Configuration Editor from this link http://zone.ni.com/devzone/cda/epd/p/id/5331, but this just leads to an error page.

Where can I get the editor? Also, do you need the DSC module too, or can the editor work without it?

Thanks.

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first column of multicolumn listbox

October 13, 2017, 11:56 am

≫ Next: call chain from error cluster

≪ Previous: Can not find/download Tag Configuration Editor

Is there something special about the first column of a multicolumn listbox?

When I select it the background turns a dark blue.

Also, without creating a property node how do I change the highlight color?

I have a multicolumn listbox in an inherited VI, and the highlight color is a orange-yellow.

Yet when I create a new VI and a new multicolumn listbox the highlight color is the dark blue.

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call chain from error cluster

October 13, 2017, 12:57 pm

≫ Next: Call Library works for 1st DLL, but not for 2nd DLL

≪ Previous: first column of multicolumn listbox

Hello dear readers,

I have stumbeld into a problem where I need to extract call chain from error clusters that are generated by labview VIs and native functions.

Here is example of 2 completely different results:

Source by definition should mean origin of error, why sometimes I see error description added into it if it can be extracted by error code??

If other strings are added how can one separate call chain from other informations ?

I could not find documentation how this string is generated and how to format source string back to call chain that will work in all cases.

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Call Library works for 1st DLL, but not for 2nd DLL

October 13, 2017, 4:02 pm

≫ Next: Arduino UNO

≪ Previous: call chain from error cluster

TL;DR: Does LabVIEW need a setting to allow one DLL to load another DLL?

I have successfully used Call Library to load our C++ DLL (dacq.dll) into a VI to send text commands and scripts to our data acquisition system. It loads, I pass strings into it, it controls the hardware, and I can acquire and display data.

But I can't get dacq.dll to load a second DLL when run from LabVIEW. We have an optional post-processing function that we call by passing this command into dacq.dll:

POSTPROCESS C:\LABVIEW\NUC.INI

NUC.ini contains another script such as:

Function1 =TwoPtNUC|functions.dll

which instructs dacq.dll to load functions.dll and call TwoPtNUC().

I know the scripts are syntactically correct, because I can run it out of a C++ terminal-like application that we wrote, and it runs correctly. After dacq.dll does its job, it calls functions.dll, which performs the image correction.

When I run the exact same text scripts from LabVIEW, the second DLL call fails.

dacq.dll echoes inputs and errors to the Windows Debug stream, and I've logged the sequence of events when sending the scripts from the C++ app and from LabVIEW. The sequences are identical up until the very last call to functions.dll, where the sequence from our C++ app succeeds but our LabVIEW fails.

I am not loading functions.dll via a Call Library function; dacq.dll is supposed to take care of that. LabVIEW only knows about dacq.dll, and that part is working fine, as evidenced by the fact that it will set up the data acquisition system and acquire data.

Is there a setting, or permission, or allocation that I need to make (or ask LabVIEW to make) to allow dacq.dll to load functions.dll? I have put the complete path to functions.dll in my PATH environment variables, but that didn't fix the problem. I wasn't expecting it to, since functions.dll lives in a subdir of where dacq.dll lives.

Any suggestions?

Thanks!

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Arduino UNO

October 13, 2017, 7:08 pm

≫ Next: LabVIEW could not create the requested endpoint (Messenger Ack Writer)

≪ Previous: Call Library works for 1st DLL, but not for 2nd DLL

I wrote a code in Arduino, which is shown below. Now I want to enter “C f1 f2”, f1 and f2 being floating point numbers, the Arduino will calibrate the output. first value will be the calibration_zero and the second will be the calibration_factor. These values can be read into floating point variables using Serial.parseFloat() or I enter “S n1 n2” n1 and n2 being integers, the Arduino record n1 and n2 in variables no_measurements and period_measurement.

How to include this in code?

const int xPin = 0;
const int yPin = 1;
const int zPin = 2;

const float supplyVoltage = 3.0;

int xReading = 0;
int yReading = 0;
int zReading = 0;
float xVoltage, yVoltage, zVoltage;

float cal_factor = 0.3;
float cal_zero_offset = 1.55;
float xG, yG, zG;

void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
analogReference(EXTERNAL);

}

void loop() {
// put your main code here, to run repeatedly:
int incoming;
if (Serial.available()>0)
{
incoming = Serial.read();
switch (incoming)
{
case 1:
Serial.parseFloat();
case 71:
readonce();
break;

defalut:
Serial.println("Command not recognized.");
}
}
readonce();
delay(100);
}

void readonce()
{
xReading = analogRead(xPin);
yReading = analogRead(yPin);
zReading = analogRead(zPin);

xVoltage = supplyVoltage*xReading/1024.;
yVoltage = supplyVoltage*yReading/1024.;
zVoltage = supplyVoltage*zReading/1024.;

xG = (xVoltage - cal_zero_offset)/cal_factor;
yG = (yVoltage - cal_zero_offset)/cal_factor;
zG = (zVoltage - cal_zero_offset)/cal_factor;

Serial.print("x: ");
Serial.print(xReading);
Serial.print("\ty: ");
Serial.print(yReading);
Serial.print("\tz: ");
Serial.println(zReading);

}

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LabVIEW could not create the requested endpoint (Messenger Ack Writer)

October 14, 2017, 3:46 am

≫ Next: usrp x310 labview

≪ Previous: Arduino UNO

I wanted to play with Channels, and check the Channel bug shown here: https://forums.ni.com/t5/LabVIEW/Messenger-Channel-Wire-ack-read-write-behavior/m-p/3699980/highlight/true#M1040502

Then I realized I see again a strange behaviour which I discovered some time ago. As I remember, I asked about this Channel behaviour in the forum, but somehow i cannot find that post again...

So I just tried to create that example in the above post. I started with that "id ack write" Num control. However, when I simply try to create a "Write ack" node for this U32 control, I get an error. I can only create ACK (Read/write) nodes, if first I create a "normal" Messenger Write node, from this I can create a ACK Read, and finally I can create the ACK Write node.

I accept if this is the expected behaviour (why would someone use ACK without Messenger Write/Read nodes?), but then LabVIEW should tell me some meaningful warning, like "Do not do this, because bla bla bla...". And not this error msg, which does not make any sense to me...

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usrp x310 labview

October 14, 2017, 6:26 am

≫ Next: LV 2015, Remote Debugging and Separate Compiled From Source Issue

≪ Previous: LabVIEW could not create the requested endpoint (Messenger Ack Writer)

I have programmed a project and used in usrp N210，the program can work sucessfully.But when I changed the device x310, it didn't work and have a problem in Fig1. When i transmitted data,the receiver part can not receive continuously but only once.Looking forward your reply. 咨询.jpg

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LV 2015, Remote Debugging and Separate Compiled From Source Issue

October 14, 2017, 9:05 am

≫ Next: Fuzzy Logic Parallel Car Parking

≪ Previous: usrp x310 labview

Has anyone ever experienced an issue where the remote debug fails with the error "failed to connect to the application"? I am working on an existing project which is a few years old. Up until now it included the compiled code with source. This project is now being managed under source code control so I went through the project and marked all project VIs to separate compiled code from source. I had no issue doing this. The application ran fine in the development environment and was built as an exe without any issues. The executable ran just fine but when we went to investigate a bug we could not connect with the remote debugger. Going into the project and unmarking "separate compiled from source" and rebuilding allows us to connect the remote debugger.

I tried the usual with cleaning the compile cache and doing a clean before the build. None of this seemed to make a difference. I have many other projects which have the compiled code separated which we can use the remote debugger to debug the executable.

Any thoughts on what the issue might be?

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Fuzzy Logic Parallel Car Parking

October 14, 2017, 10:19 am

≫ Next: tilt angles for 3 axis accelerometer(ADXL335)

≪ Previous: LV 2015, Remote Debugging and Separate Compiled From Source Issue

Hi All,

I'm trying to change the the existing FuzzyEx Car Backward Parking example VI to a parallel parking. I have made a car to stop at y = 1 with a initial car angle 90 degrees (as can be seen when you run the VI). Next step is to make a car turn towards the garage. How would I approach this step? Should I add another fuzzy logic to make a car turn?

I would really appreciate if someone could help me out to figure this out. Maybe there is an easier way to approach this parallel parking.

Thanks in advance.

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tilt angles for 3 axis accelerometer(ADXL335)

October 14, 2017, 12:07 pm

≫ Next: Labview Blowfish encrypt works but decrypting doesn't work

≪ Previous: Fuzzy Logic Parallel Car Parking

Can anyone please give me some clues in how to find tilt angles. I have developed a code to read the data. But now interested in finding the tilt angles.

Thank you.

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Labview Blowfish encrypt works but decrypting doesn't work

October 15, 2017, 12:25 am

≫ Next: PV data acquisition over LAN and server

≪ Previous: tilt angles for 3 axis accelerometer(ADXL335)

I downloaded the Labview Blowfish VI and have been looking at it. I noticed that when I'm trying to decrypt the text after encrypting it, it doesn't seem to output the original text.

Can someone tell me how I can fix this or where to look at?

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PV data acquisition over LAN and server

October 15, 2017, 3:02 am

≫ Next: Using a Network card with Multiple IP Addresses

≪ Previous: Labview Blowfish encrypt works but decrypting doesn't work

Hello, well i have an Ethernet chassis NI 9184 with sensors connected to its sub-modules. I have to acquire data from a solar cell through LAN and server, i.e. i need to connect to a server (from a PC) with Lab View installed and and then acquire my data, I want to know how to connect my chassis in order to acquire these data. What are the procedures for the server to recognize the chassis so that i can successfully acquire the data?

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