How to adjust the value of the digital potentiometer such that it outputs a desired value of voltage.

Hi all, I have a digital potentiometer in a circuit which needs to be adjusted to control the voltage it receives. Its a 2 channel 256 position AD5207 dig pot. I need to adjust the wiper position of the dig pot(which we need to do using labview)such that it outputs a particular desired voltage value.For example, if the input to the pot is 200mV, then we need to adjust the pot such that it sends out a value of 50mV. How can we do that?? Please help. The DAQ iam using is PCI-MIO-16E-4. Thank you......Ausuri

Hi Chaitanya,
We never know who our audience is when we answer these questions. There has ben quite a few occations when I have insulted people because my answers was too basic.
The creattion dates on the files show that "project xx SPI.vi" has the latest mod date.
Open it and take a look at the diagram.
Put the VI in execution-highlighting mode (click the light bulb) and the run the VI and watch what happens.
There are pictures included in the diagram that illustates what is happening.
If you have specific questions after watching the VI run, ask away.
This is a wonderful example!
I would have charged big bucks for this example.
Good work Wha!
Ben
Ben Rayner
I am currently active on.. MainStream Preppers
Rayner's Ridge is under construction

Similar Messages

How to adjust adhoc query when the database table changed.

DearFreinds,
I have created an adhoc Query , however after few days there was a requirement to remove some fields and change the length of some fields . Now the Adhoc query showing as to adjust , however when iam trying to adjust nothing is happening. Could any one let me know how to adjust with the table strucutre in the adhoc query.
Regards
madhu.

Hi Sumit,
Yes i have adjusted the database from se11 itself by going into utlity > adjust database . However i can still see the
adhoc query -> infoset asking me when iam trying to go in change mode saying the database table has been changed do you want to adjust .
I have adjusted by going to more functions still there is no change. Please let me know what exactly i have to do.
regards
madhu

How to detect keystroke and control a digital potentiometer?

Dear All,
I want to use PCI-1200 to control a Xicor X9C103P digital potentiometer.
The procedure is as follows: If the computer detects any keystroke from
either UP or DOWN arrow keys, it send a chain of digital signals to a
digital potentionmeter to increase or decrease its resistance accordingly.
Each keystroke control the potentiometer to change a fixed amount, say,
around 500 Ohm. How to detect these keystrokes using LabVIEW and
send to digital potentiometer through PCI-1200?

If you are refering to the ability to capture user key strokes you will need to add a listener to the class. If is a matter of is it a charater or a number then look into isDigit. Or are you trying to capture Hot-Keys? Please specify and will see if we can help - Bart

How to convert a analog signal to digital signal

Hello,
How to convert an analog signal into digital signal such that every sample of analog signal corresponding to 1.2V will be represented as '1' in digital signal and other samples of analog signal(that are not 1.2v) will be represented(converted) as '0' in digital signal.
And how to display both wavefroms or signals in graph indicators.
Thanks.
Solved!
Go to Solution.

If you have 1000 samples, and you want to convert to digital, you are going to get 1000 digital values. Attached is what I mean.
Unofficial Forum Rules and Guidelines - Hooovahh - LabVIEW Overlord
If 10 out of 10 experts in any field say something is bad, you should probably take their opinion seriously.
Attachments:
Analog_to_Digital Hooovahh Edit.vi ‏52 KB

How to save a value in a .txt n retrive back the exact value from the file?

Well I have a number. Let's say 600. I need to save this value in a .txt file so that I can retrive this value. I tried using the below source code. It can be executed but I'll get num 49 everytime I execute it even though the value in my .txt is 600.
try {
               File inputFile = new File("Lt.txt");
               File outputFile = new File("outagain.txt");
FileReader in = new FileReader("Lt.txt");
FileWriter out = new FileWriter(outputFile);
int c;
          c = in.read();
          in.close();
System.out.print("\nggggggggg"+c);
in.close();
               } catch (IOException ex) {
               System.out.println("IOException:"+ex.toString());

Thank you. I execute the program below. I can now retrive the data from the Lt.txt. But the value is limited to 3 digits. For example, the content of my file is 777888.
When I run the program, I only get 777. How can I retrive the whole exact number?
import java.io.*;
               class Test {
               public static void main(String args[]) {
               try {
               File inputFile = new File("Lt.txt");
               File outputFile = new File("outagain.txt");
               FileReader in = new FileReader("Lt.txt");
               FileWriter out = new FileWriter(outputFile);
               char[] tmp = new char[3];
               int cnt = in.read(tmp);
               System.out.print("\nRead: ");
               for (int i = 0; i < cnt; i++) {
               System.out.print(tmp);               }
               System.out.println(" ");
               in.close();          }
               catch (IOException ex) {
               System.out.println("IOException:"+ex.toString());          }     }}

How to adjust the Viewer window to less than 25% ?

Hi all experts,
At the top of the viewer window, there is a dropdown to select the % of the screen. The option given are FIT, 25% ... etc.
But how to adjust to smaller than 25% ? Or for that matter, how to type in a percentage number ?
Thanks

Thanks Tom,
So the minimum size is set at 15%.

How do I use the VIs for the Fluke Hydra Series 2620a multimeter?

This message refers to the VIs found at this link:
http://sine.ni.com/apps/we/niid_web_display.download_page?p_id_guid=E3B19B3E9468659CE034080020E74861
How do I use the VIs for the Fluke Hydra Series 2620a multimeter? I am conducting a Senior Design Project at Temple University. It is a Control System where I need to read voltages from sensors and output voltages to different system components. I am trying to set up a VI using the VIs found above to make sure that I can successfully read and send voltages. There was no documentation given with the 2620a VIs.

Unfortunately, you've got a very old driver for an old instrument. The only available help is to turn on Context Help and move your mouse over the VI icon. It doesn't appear to have any help for individual controls and indicators. The only good news is that it appears to be a simple instrument with only a few functions. There's some main ones line initialize (to set serial port), configure channel, configure instr, and read values. One main thing is whether you're using gpib or serial, Each front panel has a setting. If it's gpib, set the port to the gpib address. If it's serial, set the port to one number less than the com port you're connected to. For example, if you're using Com1, set the port to 0. For the other controls, I'm afraid that you're going to have to try and compare what's there with the controls and settings of the actual instrument. Having access to the instrument manual will be essential. I would engourage you to experiment a little. There's probably very little chance of damaging the instrument especially if nothing is hooked up to it. Send a command and see what happens or set the instrument up manually and see if you can reproduce that via remote control.

How to clear the fields of the screen ?

Hi,
I'm having two fields for selection..when i press enter after entering some values,based on that my table control will get filled up..and when i double -click on that row in table control i get all the values of that row in the respective fields in my tabstrip..all these r in same screen 100..and in tabstrip i have 5 tabs with 5 subscreens..containing the fields of table control..now that when i enter a value in the selection screen fields..my table control is getting added with a second row of values as required..but my problem is that the values of the tabstrip should get cleared..this is not happening..i wrote logic like if my tablecontrol is getting appended the values from tabstrip should get cleared..all the fields are getting cleared except the fields of tab which is active..how to do it..

Hi,
Try this out.
declare a variable in Top Include
data : appended type c.
if the appending to the internal table is success means sy-subrc = 0
make appended = 'X'.
go to the PBO of subscreen of the tab where you want to clear the data
if appended = 'X'.
clear appended.( this is must otherwise for every call of the subscreen of this tab the values get cleared)
here clear the value of the subscreen of the tab strip)
endif.
The same can be achieved using the OK_CODE also
Regards
Ramchander Rao.K

How to implement such that "Order reason" not allow the SO to generate PO?

Hi,
While Sales Order creation, if 'Order Reason' is "Poor Quality" then I do not want the Purchser order to be generated.
such that the system should not allow the Sales order to generate Purchade order until the order reason is changed.
Please tell me how can I do this?
Regards,
Chamandeep

Hi Vinod,
This is 3rd party Sales order creation situation.I am Creating the PO using the Item category TAS.
The PO is generated and then the PO generates the Sales order in another SAP system using ALE.
What I want that if a particular "order reason" is chosen in the sending SAP system while creating the Sales order, then it should not Let the PO be sent to the another system.
Do tell if any other information is required?
Regards,
Chamandeep

How do I view the DESKTOP (not the hard drive) of my TARGET computer?

I've successfully linked two MACS using a Firewire cable and TARGET mode. When I click on the Target computer's icon, I am linked to its Hard Drive. But what I really want is to see the DESKTOP of the Target computer, and be able to drag files/folders from the Target computer to the linked computer. Is this possible? If not, how do I locate the files/folders on the Target computer desktop? Thanks

In FW Target Disk Mode only the hard disk drive and its folders/contents are seen
by the host computer viewing the TDM-enabled second machine.
If the status of the Target Disk mode computer were such that you could gain access
to a User account's Desktop folder in that user's folder (sans permissions issues)
the contents on a User's desktop folder may be retrieved. But not likely in TDM.
When the computers are both near equal in health, a way to gain access to a
remotely attached computer's hard disk drive, desktop/Finder, etc would be
through a Remote Desktop application; one could remote Administer that one.
There may be another way to do what you want, but viewing the FW TDM
enabled computer from the healthy one used to gain access to it, as though
it were a healthy computer and see its desktop file (finder) is unlikely.
The status of this questionable computer being an unknown, other ideas
would have to be based on more information to determine other options.
{and I see by the time I typed all this & had minor distraction, here, you
did get at least two replies that direct you to the user desktop folder.}
Good luck & happy computing!
{edited}

What are the units of the DAQmx counter?

Hello,
I created this VI and several similar ones a few months ago, but, I have forgotten some of what I did back then. I believe that this VI should measure period, using the counter on the DAQ chassis. Can anyone tell me the units of the period measured? I think it is seconds, but, I am trying to figure out how to figure that out! The values of the period are generated by the DAQmx READ function in the WHILE loop. What units is that function outputting to the array? What are the units of the array elements, essentially? See the attached VI.
Also, how do you know? I opened the DETAILED HELP for the DAQmx Read (Counter 1D DBL NSamp) shown in the VI but, I can't find anything on the units of the data coming out of the terminal labeled DATA with the orange wire, which is actually an array of periods, and we take the average of the most recent 15 or so period measurements.
I had a suggestion months ago for an online NI manual containing a description of Buffered EdgeCounting measurements, but, when I went to find it, the link had been changed by NI, so, I can't find that manual, but, I think the answer is probably there, because I recall that manual being very useful when I did this before.
Thanks for the guidance.
Solved!
Go to Solution.
Attachments:
continuously measure period buffered_singlechannel_forum Nov 13.vi ‏33 KB

HI dav2010,
When you create a Virtual Channel, you should specify the units the counter task will use. There are several options which are listed in the help here:
http://zone.ni.com/reference/en-XX/help/370469AA-01/lvdaqmx/mxcreatechannel/#DAQmxCreateChannel%28CI...
I am not on a computer with LabVIEW right now, but I believe the default should be ticks, which is the number of ticks of your device's timebase. You can find that information in your hardware specifications.
Regards,
Chris E.
Applications Engineer
National Instruments
http://www.ni.com/support

Is there a limit on the size of the input for the Solve Linear Equations block?

Hello,
I'm trying to figure out why the Solve Linear Equations block will properly function with some sets of data and why it won't with others. What my program is doing is taking a signal and comparing it with a batch of sine and cosine waves to try and pick out patterns in the data. I have different sample sizes and it seems to work when I throw 3900 points at it. However, I have another set with 4550 points and it gives me incorrect amplitudes for my sinusoids. Is there some limit to the size of the matrices that I can give this block? Or is there some other workaround that still allows me to keep all of my data?
Thanks,
David Joseph

Well, the best way to show what I expect is to see the entire program. It's pretty evident that when looking at the graphs, something isn't right. What is supposed to happen is that the runout amplitudes are found, and then those sinusoids are subtracted from the initial data, leaving tooth to tooth data and noise. When I use the larger arrays, it seems as though not all of the data gets through (count the peaks on the product gear runout graph vs. initial) and the amplitudes are much to small, such that nothing is really taken out and the tooth to tooth data looks like the initial data.
Also, we will also be using an FFT, but it will be limited to only determining the frequencies we should check. I've fought with the fft blocks quite a bit and I just prefer to not use them. Plus, the guy I'm writing this for wants exact answers and does not want to pad or resample the data or use windows.
The exact number of data points isn't important (ie. 4550 vs 4551) since I use the array size block to index the for loop.
As for typical values, they can change a lot based on materials. But, the original 3900 data point sets and the 4550 data point sets used practically identical gears. So, use the original 3900 sets I've included as references (check the RO array block numbers to compare).
I've included 3 3900 samples, 3 4550 samples, and 3 4550 samples that have been truncated to 3900 or so as constants on the block diagram.
Also, the check for additional runouts (like 3 per rev, 4 per rev, etc..) is optional, but if you choose to use it, use positive integers only.
I don't know how much of this program will make sense and I have wires running everywhere.. so good luck. Keep in mind I'm only a student and I hadn't touched Labview until about 2 or 3 months ago.
Thanks,
David Joseph
Attachments:
Full example.vi ‏139 KB

PS CC - I have a B/W background which I flattened - Then, change to RGB and add an RGB color graphic - print out makes background a greenish color - Can't figure out how to adjust.

PS CC - I have a B/W background which I flattened - Then, change to RGB and add an RGB color graphic - print out makes background a greenish color - Can't figure out how to adjust.
Thanks,
Dave

If the grayscale looks ok on screen, you are probably not setting up your print correctly. What OS? What printer?

Export Project and Change the Duration Cause the Finish date error

I use VB.NET to create a MS Project Instance and use this Instance to add task, and set task's Name, Start and Finish, the Project file is created successfully, and the Duration value will be automatically generated by Project, but if I change the Duration
value in Project, the Finish date isn't correct, for example, if I set the the Start is "10/21/2014" and Finish is "10/31/2014", the generated Project file has a Duration value is "9 days", and if I change the Duration value to
"2 days", the Finish date will be changed to "10/21/2014", why this problem happen? I have no idea about this problem.

when you set Start is "10/21/2014" and Finish is "10/31/2014", the generated Project file has a Duration value is "9
days" because it is taking Saturday and sunday as non working days.
By default in Project server calendar both Saturday
and Sunday are non workng days. If you want to make these day as working day you have to configure the calendar once you will do it then it will display duration value as 11.
When you change the value then after changing value click on Calculate button so that project server can calculate value correctly it is not required to click on Calculate
all the time but some time project server takes time to reflect the chnages but if you will publish the project it will calculate correctly and display proper finish date ( I
change the Duration value to "2 days", the Finish date will be changed to "10/21/2014 as 10/23/2014)
kirtesh

I want to output an arbitrary waveform using LabView onto the oscilliscope through the DAQ2005 card. Can anyone help please?

Hey guys,
I am new to LabView and my final year project depends on it! Please help as much as you can!
I am trying to output an arbitrary waveform on an oscilliscope. The shape of the waveform depends on user input parameters like no. of samples, amplitude of each sample and the frequency of desired waveform. Please refer to attached Arbitrary_Wave_Display.vi. In the attached vi, the desired waveform is displayed on the front panel. My project requires that I output this waveform through the analogue output channels of the 2 DAQ2005 cards that I have. When I connect the output of th Arbitrary_Wave.vi to the input of the AO write express vi, there is no output of the oscilliscope. I believe it should be connection problems with regards to while loops and loop conditions. I have also attached my attempted vi.
Please feel free to give some advice. It is greatly appreciated,
Best regards,
TheApprentice of LabView

You didn't attach any VI and what is the DAQ 2005? I don't know of any NI board with that model number. The analog output functions on the LabVIEW DAQ palette only work with NI boards.

How to adjust the value of the digital potentiometer such that it outputs a desired value of voltage.

Similar Messages

Maybe you are looking for