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Re: Installation of K & R type TC on same location but produce different output temperature

March 25, 2019, 7:45 am
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Granted I do not have any experience with NI-DAQ devices but I do use thermocouples and other devices for reading them. 

 

When I see someone using a DAQ for thermocouples my first question is:

 

How are you handling Cold Junction Compensation?

 

Most devices designed for reading thermocouples have an internal cold junction reference, most DAQ device do not.

 

Also remember that when reading thermocouples you are measuring millivolts/degree, that puts the DAQ in a very low voltage range and will be very sensitive to any noise. Possibly some measurement integration would help with this but most tiem noise needs to be dealt with on the hardware level. Like grounding all unused inputs of the DAQ to start with...

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Re: Serial ports not appearing in MAX - VISA installed.

March 25, 2019, 7:48 am
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My colleague checks more than 300 Arduino cards for troubleshooting if there is USB communication problem or not. At the end of the day, COM port name showed up like COM219 at device manager but at LabVIEW it did not show up as COM source. I reinstall everything but it did not help. Finally, I uninstalled the device which is showed up as COM219 and scan for hardware changes. At the end of this, COM port is changed to COM4. I tried again and it worked. It is obvious there is some limitation for selection COM port for LabVIEW, be careful if it reaches more than 200.

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Re: Reading a load cell in LabVIEW 2018 using Arduino and HX711

March 25, 2019, 7:50 am
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we are using arduino uno sir

  • Capacity : 20kg / 44 lbs
  • Recommend Excitation Voltage : 5V DC
  • Max Excitation Voltage : 10V DC
  • Rated Output : 1 ±0.15mV/V
  • Overall Precision : 0.03%F.S
  • Input Resistance : 1115 ± 20 Ohm
  • Output Resistance : 1000 ± 20 Ohm
  • Insulation Resistance : 2000 Ohm
  • Working Temperature : -20°C ~ +60°C
  • Compensated Temperature Range : -10°C ~ +65°C
  • Safety Overload : 120%
  • Total Size : 80 x 13 x 12mm (L*W*T)
  • Thead Hole : M4 Screw
  • Cable Length : 150mm/ 6''
  • Material : Aluminium Alloy
  • Weight : 32g
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Re: Reading a load cell in LabVIEW 2018 using Arduino and HX711

March 25, 2019, 7:53 am
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Hi Charshith,

 

we are using arduino uno

You already said so.

 

Capacity : 20kg / 44 lbs …

I guess these are the specs of your load sensor.

What should we do with those information?

 

How does your circuit look like?

What have you tried so far?

Where are you stuck?

What is your specific LabVIEW problem?

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Re: Reading a load cell in LabVIEW 2018 using Arduino and HX711

March 25, 2019, 7:54 am
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this is our project vi sir.we are planning to make it operate on a valid load.so trying to aquire load data sir 

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How to find the distance travel by particle using optical flow function ?

March 25, 2019, 8:05 am
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Hello All,

 

I am working on a project where I have to calculate the velocity of the moving particle and then have to move the sample stage with same velocity in a opposite direction of particle motion.

 

What I am doing?

I wrote programme in LabVIEW

whats it does?

1)Open camera and load the configuration

2)Take first image, lets assume it a previous image 

3)Take second image and assume it as a current image

4)Do image processing

5)Use both current and precious image and apply to the optical flow function to find the distance travel by             particle.

 

what is the problem?

1) Optical flow VI (LKP), calculate the particle distance only from the defined pixel location in feature in tag at optical flow VI , see image below., but I my case particle can be anywhere and I have to find the distance travel by the particle to find the velocity, so do any one know how to find the distance travel by particle from the random locations.

feature in.JPG

 

 

 

 

 

 

2) can any one explain me in which unit distance array return the travel distance of the particle?distance travel.JPG

 

 

 

 

 

 

 

 

 

3) What each parameter does in options at optical flow VI?options.JPG such as window size, iteration and level?

 

 

 

 

I have attached VI for more information.

 

Please let me if you know the answers of any above asked questions.

 

 

 

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Re: Remove Elements of Array

March 25, 2019, 8:05 am
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Please correct me If I am wrong, with your example I get a fractional number, that number is not any index ? I mean i need to get index 0 , when the time shows 00:01:00 , not before and not after , and i need to get index 1 when the time shows 00:02:00 , not before and not after, your example gives us values in increment when you are close to the point ,  Im not sure about its accuracy whats the name of the block i32 you placed on your schematic ? Furthermore your programme it work in a sequencial way but mine you didnt need to have all the index in order.

I am not sure either how works with the values I got , I had one case structure to introduce the differents rows or -1 that it willl not do anything,if I have fractional values , may i ask you again how i know when i have to select each row of the the next array.

I want just ask politely if there is any way of desactivated a previous position that we have already used or  maybe a way of gettig through your proposal the value of the index in entire way. thanks . I really appreacite it your help.  

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Re: Write 2D array row-by-row in Level 5 MAT-File Format

March 25, 2019, 8:07 am
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Re: Help/advice for creating my own LabVIEW driver for LCR meter 880?

March 25, 2019, 8:09 am
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If you want to develop a LabVIEW "Plug and Play" driver, you can go to "Create Project" and select "Instrument Driver".  Then follow the prompts to create a basic template.  Be prepared to change much of the guts as you substitute your instrument's SCPI commands for the defaults.  (The instrument usually has some version of a programmer's guide.  If not, programming instructions are probably in the user manual.  If it's not there, either, then they probably don't want you programming it because they want you to purchase their software.  Smiley Wink)

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Re: Perpetual vs Subscription Renewal

March 25, 2019, 8:12 am
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I agree with @altenbach. You should contact NI Sales Department (especially if you don't know your local sales manager). You can reach our Sales department at (877) 388-1952, found on the NI Contact Us page.

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Re: Getting data from FPGA using DMA FIFO from target to host

March 25, 2019, 8:16 am
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You were right, I checked the power supply, it outputs a signal with peaks of 100Hz instead of giving a dc voltage..

 

The way I connect the scope is, instead of the inputs going into the ni9205, I put in the same wires to the scope.

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Executable won't run

March 25, 2019, 8:20 am
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I have a program that runs fine under the development system, but the executable won't run on the same computer, much less a target computer.

It appears to stop in the initialization section. The log file is not created and the Excel data does not appear to be read. I have verified that the Files folder is there and the Excel file is in it.

I enabled debugging, but that did not help. The only front panel button that works is the Stop button.

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Re: How can I properly identify a file type in LabVIEW?

March 25, 2019, 8:23 am
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In the future feel free to give thanks by giving kudos rather than replying to really old threads.  Oh and in modern LabVIEW versions there is a Get File Extensions on the File I/O palette to help with this.  Before that there is an OpenG function too.

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Re: Serial ports not appearing in MAX - VISA installed.

March 25, 2019, 8:21 am
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Re: Remove Elements of Array

March 25, 2019, 8:25 am
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Let me extend the previous file I posted to another one bigger where you can see what I meant 

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Re: LabVIEW proverbs!

March 25, 2019, 8:32 am
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After a day of chasing down why unused code was showing up in a project, it occurred to me that...

 

Using Auto-populating folders is a lot like spraying contact adhesive on the bottom of your slippers.

Sooner or later you will pick-up a crumb that will cause you pain until you decide to toss out the old and start over again.

 

Ben

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Re: Highland Technologies T560 VI

March 25, 2019, 8:33 am
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Bob,

Thanks for the reply. I am further along now than when I posted. I am successfully sending commands and reading responses over ethernet simply using TCPIP open, write, read, and close VI's. So I have the basic communication already working. I am working on my own group of VI's.

 

I tried the MAX program but could not get that to work. The button for "add new deice" does not show up. Someone here with more Labview experience than me thought I didn't need MAX and that turned out to be true. Still it bothers me that MAX does not seem to work the way the manual says it should.

 

My original post was to see if anyone else had already written a comprehensive VI for the T560 so I could leverage someone else's work.

 

The manual for the unit is linked from their website, in case you are interested.

https://www.highlandtechnology.com/dyn/files/doc/T560MANK5.pdf

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Re: Executable won't run

March 25, 2019, 8:43 am
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Put a path indicator on one of your paths and rebuild the application. You will find that the path in the executable is not what you think it is.

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Re: Convert number to string as currency!

March 25, 2019, 8:46 am
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Re: LabVIEW proverbs!

March 25, 2019, 8:51 am
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Pessimist: If it's working, there must be something wrong.

Optimist: If it ain't broke, don't fix it.

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