Measure and Record Temperature and Pressure

Evening guys!
I really need some help for my program.
I am asked to write a program that can measure and record local temperature and air pressure. I have already set up the hardware, so I can get voltages for temperature from channel 0 of mydaq, and pressure from channel 1. However, I don't know how I am suppose to build the program. Can anyone help me on that?
I need the value and graph showing at the front panel, and record them as a txt file as well.
Thanks a lot!
Best,
Rookie R

I would recommend looking at the online LabVIEW tutorials
LabVIEW Introduction Course - Three Hours
LabVIEW Introduction Course - Six Hours

Similar Messages

Producer-consumer design for temperature and pressure acquisition

I am working on my first LabVIEW program in version 8.6. I eventually want to be able to take both temperature and pressure measurements (6 RTDs and 2 pressure sensors), write them to files, compare the temperatures, and then turn 9 heaters (2 zones) on and off depending on the temperatures and temperature differences. I will also need to have necessary alarms and emergency shut down if something overheats.
To start, I am just working with temperature. I have made a program that reads 2 RTDs with the NI9217 in the cDAQ 9172. It plots the temperatures and writes them to file. Then it compares the 2 temperatures. If the temperature difference is greater than the user defined difference, an LED alarm lights up. This loops until the user presses the stop button.
The program runs, but then I get a 200279 error. It says that increasing the buffer may do the trick; however, I read online and watched a video on the producer/consumer design, which I think might do the trick. I am hoping with the producer/consumer design that I will be able to sample the temperatures faster (especially once I have 6 RTDs and 2 pressure sensors). Right now it takes about 11 seconds for the loop to run.
I have played around with trying to do the producer/consumer design, but I am not having much luck. I am not sure how to set it up. Do I need to have one producer loop with the DAQ assistant, and then 2 consumer loops (one for each RTD)? If I have 2 consumer loops, how do I then synchronize the data to compare the temperatures that were taken at the same time?
If I only use 1 consumer loop, how do I separate the data that is coming from one RTD vs. the other RTD?
Any comments or suggestions would be greatly appreciated.
I have attached my current VI for reference.
Attachments:
RTD differential temp.vi ‏260 KB

I have attached my attempt at the producer-consumer design. It runs much faster than the VI I attached in my first posting; however, it has bugs.
When I press the stop button, I get an error 1 (occurred at Dequeue Element).
Also, how do I get the graphs to plot with a fixed axis? For example I would like to see the plot of 5mins worth of data. I have tried turning off the autoscale, but it does not keep the axis from changing.
Any suggestions on how I can clean up this program? When I get to adding more RTDs, should they all be in this same consumer loop?
What would be the best way to add in the pressure data? With another producer loop and another consumer loop?
Attachments:
RTD producer_consumer.vi ‏263 KB

Creating info records: units of measure and conversion factor

while executing the session, I get the message 'Please check units of measure and conversion factor', what does it indicate?

resolved

How to measure and log frequency with fieldpoint CTR

Hi,
I am developing a data acquistion and control system for an engine dynamometer using the fieldpoint modules and Labview. One of the most important signals is the engine speed, measured in RPM. The RPM signal is a 0-12V pulse where one pulse equals one revolution of the engine. As well as being an important piece of data for later analysis, engine RPM will also be in the input into a PID controller, so the signal must be both accurate and have a high measurement frequency.
Currently I am using the FP-CTR500 modules to measure the frequency of the signal. I am already aware of the included frequency measurement VI example, as well as the one posted before for low frequency measurements, and I have gotten both to work with my setup. I would be using the low frequency VI becuase the max frequency measurement would be in the 200Hz range.
The first problem I am having is with the structure of the VI and how the data is output. The case structure in the VI activates when the counter is read and resets the counter, then switches to the next case. I would like the RPM number to output out of the case structure into a write_to_file VI and PID controller input. The problem is that when the case switches, the counter is reset to 0, which will be recorded in the written file.
This is some example output data (RPM):
1232
0
2321
0
2400
0
2521
0
The data is being written correctly, but of course I can't have 0 readings when the case structure changes. This would be especially problematic when input into a controller VI.
The next problem I am having is with sampling rate. If I were to use the low frequency measurement VI, the sampling rate of RPM would be variable based upon the the speed of the signal. Or, the original frequency measurement VI has an adjustable sampling rate. Of course, in my system there are a number of other signals that need to be recorded at the same time. I have found that as I am collecting data, the "write to file frequency" is entirely dependent on the read frequency of the frequency measurement. Therefore, if I had set the read frequency VI to read at 1 Hz, data will be recorded only every 2Hz. Ideally I would like an overall measurement frequency of all channels (mix of analog and digital) to read between 20-50Hz, but if I am limited by the frequency measurement.
Any ideas on how to solve this problem, either through Fieldpoint or Labview?
I can post my VI if this help.
Thanks,
Huang

Thanks for your reply.
I should probably describe my current setup before I go into anymore details with the problem. As for my specific setup, I am using an FP-1000 connected with an AIO600, AI110, CTR500, and TC120 all running through the RS232 line to a desktop running labview 8. The actual counter module is reading a tachometer signal output from a separate engine controller. THe output is a 0-12V ON 50% duty cycle signal. As for data logging, i am simply using a "write to measurement file" Express VI. I have a while structure which holds all of the express VIs which access the fieldpoint IO, and these are all routed to the "write to" VI.
As for the specifics of the data logging problem, as I said, when I set the count frequency of the "Fieldpoint Frequency Measurement" VI to 1Hz, (which means the VI calls the case structure at 2Hz), the "write to measurment file" VI is called at the same rate (2Hz). Which means that the overall logging rate of the VI is only 2Hz. Is there someway to decouple this?
I was able to solve the problem of calling the frequency variable from the case structure by using a local variable which is called outside the case structure.
And now I have been having a lot of problems with reading the actual frequency from my engine controller. THe actual signal will only range from 0 to around 200Hz. I noticed, by comparing the actual signal to what was being read in my labview program, that after around 80Hz the signal increases by around 1.5times more than the actual signal. ie. Actual signal = 100hz, Read Signal = 150Hz. After trying to figure out what was the problem, I decided to change the Noise Filter settings to 200Hz. It actually worked for all the frequency ranges up to around 150Hz but after that the filter attenuates the signal to the point where the actual signal is 160Hz, but is being read at 100Hz. My question is if there is a way to change the actual filter setting outside of the 2 given setpoints (200hz and 40khz) or if you have any other suggestions on how to fix this problem? I was thinking of creating a noise filter input in MAX so that i could play with the values in Labview, but am i only limited to those two filters?
Thanks again for your help,
Huang

Measurement and Automation Explorer not installed correctly

I have a trial version of LabView 8.5. Upon trying to change the Instrument I/O Assistant, I get "Measurement and Automation Explorer not installed correctly. Please install from driver CD." Well, I don't have the CD since this was a trial download.
Basically, what I am trying to do is this: I want to pull 4 variables/tags from an Allen Bradley PLC and log them to an Excel spreadsheet. I am using RSLinx to communicate with the PLC, and LabView to compile the info.
Any help would be appreciated.

Any Ideas? I have the program running right now, and I'm kinda in a bind. I also tried RSView32 Works to log the info, but there isn't enough flexibility in logging. I need to log flow rate test results from a large automated machine. The mahcine does a number of operations, but we are most concerned with these four tags (since it conducts four tests at once). The problem is, the cycle time varies with the lot of product. Some products require more time as the process is more delicate. So, I can't use a time-interval logging method.
As for variable change, I can't do that either because it records the 4 test results in series; not all at the same time. That, and if the test is aborted (no tube), the previous test result value stays in the tag until there is a successful test.
I found a variable that changes once per cycle. I'd like to log the four tags once per cycle.
BUT I can't do anything until I get the I/O Wizard working.

Units of measure and conversion factor

while executing a session, I get the message 'Please check units of measure and conversion factor', what does it indicate? there are fields like order unit, conversion (purchasing) in creating info records transaction ME11.

in bdc when ever u r working with quantity and price fields it is better to move this fields in to string and do the concatenation kind of stuff..............
reward points if helpful................

Continuously measure and write waveform using tdms

Hello everyone,
I am doing my thesis using Labview 2010(since it is only version avaliable in University currently ). I need to read and record data from microphone(currently using simulate signal since i need to make program work first) then save and analise it(didn't reach that point yet). I tried to use event structure so i can record and then read tdms file. But unfortunatly it records only small piece, then i inserted while loop so it will record continuosly but program doesnt respond after i push record and i can only close it manualy from toolbar. Please could anyone help me or suggest something since i am not very good at Labview and any feedback is welcome. Here is what i have done till now. I tried to search forums for some similar solution but could not find anything usefull(some had much newer version so i could not open). Thank you.
Solved!
Go to Solution.
Attachments:
test2.vi ‏45 KB

Hi and welcome to the forums,
The reason you cannot stop the recording of the waveform or exit the application is because you have the event case configured to "lock panel until the case for this event completes" (in edit events). This means that LabVIEW will not respond to user interaction until that event structure completes but because you rely on being able to press the while loop stop button to finish the event structure means you have a deadlock and have to abort the VI.
The architecture of your application is not ideal - I would strong advise against having anything that takes a long time to execute inside your event structure for the very reason above (obviously you can untick lock panel as a quick solution). I would suggest having a look at the producer/consumer design pattern (events) (new... > from template > frameworks) as this would be more appropriate for your application. You can handle your button presses in the top event structure and have a state machine in the bottom loop for starting, running and stopping your data acquisition.
The idea is that you only do very little inside the event structure so it frees up the front panel but the messages (e.g. start/stop acquiring data, exit application) are handled by another loop.
I don't know if it ships in LabVIEW 2010, but in 2012/2013 there are sample projects that include a "continuous measurement and logging" project which might be suited to your application. There are also examples for state machines and queued message handlers.
Certified LabVIEW Architect, Certified TestStand Developer
NI Days (and A&DF): 2010, 2011, 2013, 2014
NI Week: 2012, 2014
Knowledgeable in all things Giant Tetris and WebSockets

Is it possible to change the resolution of indivdual channels in measurement and automation explorer using a VI

Hi
I'm acquiring data on 8 analog input channels using a PCI-6052 E card. The data on channels 5 thru 8 is going to be between +1V and -1V. So for greater resolution I'm manually changing the range of these channels to +1V to -1V in the measurement and automation explorer. Is there a way by which I can make these changes directly using a VI ?
Thanks,
Shiv

Hi
Yes you can, but only if you use the "AI Config" VI. AI config allows different gains for different channels. The "channels" and "input limits" inputs of the VI accepts arrays. The first element of the input limits array corresponds to the first element of the channel array. Check the "cont acq&chart (buffered).vi" in the LV examples. There you see what I mean!
Regards,
Luca

Deployment error when modifying measures and my heirarchy

I am working on Lesson 3 on analysis services tutorial where i am modifying measures and my heirarchy
and this is my error message.
Warning 1 Dimension [Date] : Avoid visible attribute hierarchies for attributes used as levels in user-defined hierarchies. 0 0
Warning 2 Dimension [Customer] : Avoid visible attribute hierarchies for attributes used as levels in user-defined hierarchies. 0 0
Warning 3 Dimension [Product] : Avoid visible attribute hierarchies for attributes used as levels in user-defined hierarchies. 0 0
Warning 4 Dimension [Product] : Define attribute relationships as 'Rigid' where appropriate. 0 0
Warning 5 Errors in the OLAP storage engine: A duplicate attribute key has been found when processing: Table: 'dbo_DimDate', Column: 'CalendarQuarter', Value: '4'. The attribute is 'Calendar Quarter'. 0 0
Error 6 Internal error: The operation terminated unsuccessfully. 0 0
Error 7 Server: The current operation was cancelled because another operation in the transaction failed. 0 0
What can i do to fix this?

Hi Cook959,
In your scenario, it seems that the issue was related to the error message.
Errors in the OLAP storage engine: A duplicate attribute key has been found when processing: Table: 'dbo_DimDate', Column: 'CalendarQuarter', Value: '4'. The attribute is 'Calendar Quarter'. 0 0
There are many reasons that can cause this issue, here are some blogs which list the reasons and explanation, please refer to the links below to see the details.
http://ms-olap.blogspot.com/2009/11/duplicate-attribute-key-has-been-found.html
http://blog.oraylis.de/2013/08/a-duplicate-attribute-key-has-been-found-during-processing-revisited/
Hope this helps.
Regards,
Charlie Liao
TechNet Community Support

How do I increase the field of view in Measurement and Automation Explorer (MAX) Version 3.1.1.3003

I am using Measurement and Automation Explorer Version 3.1.1.3003 to view pictures on a pc that are being sent from a video camera looking through a microscope. The image I see in the viewfinder of the microscope is MUCH smaller than the image that is displayed on the pc screen. Looking through the viewfinder of the microscope, I can see ~20 mm across the object, but the display from the camera in NI-MAX shows ~4.5 mm across the object. How can I change how much of an object is displayed on the screen in NI-MAX?
The camera is attached to the microscope with a camera adapter on the top of the microscope. The lenses the camera "looks" through and the lenses used when one looks through the viewfinder are the same, so theoretically, there should be no difference in what is displayed on the pc and what is seen through the viewfinder. We have ruled out the microscope and camera as the cause of the problem, which narrows it down to the NI-MAX software itself.
I saw in the forums that you can zoom out on an image; however, this does not change the distance across an image that is seen, just makes the picture of the same ~4.5 mm across the object smaller in size.
Any ideas or suggestions?

I have attached a picture of the object's image being displayed on the pc monitor. Where the field of view (FOV) in the microscope is almost 30 mm, the FOV displayed onscreen is about 7 mm. After contacting companies various times I discovered there was a reducing lens that goes in the C-mount adaptor, but it is over $300.
I thought maybe that the FOV could be changed in in NI Measurement and Automation Exploer (NI-MAX). Any ideas?
Attachments:
field of view.png ‏2437 KB

Pie chart with two measures and date dimension navigation not working

Hi Experts,
Pie chart with two measures and date dimension navigation not working. Any help is appreciated.
Thanks
V

Hi Deepak,
I had time dimension in the RPD.
I have stacked bar chart with same time dim like year & month in the report. when I go to legand and set navigation it is working fine. But not with pie chart.
I am not not sure what is the problem. When I click on Pie chart it is not navigating to the target report. Can it be any other issues..???

How to get the Multiplied value between measure and a dimension base on user selection using dynamically

Hi Experts,
We had developed a cube with the Measures and Dimensions.
I had a requirment as the measures should be muliplied by the currency value of different countries and get me the results.
For Example.
In SSRS report, the user will select "EUR" then the measures should multiply with the EUR based value for the particular month and get the result in the SSRS report. If the user select any other currency value, that should multiply with the measure
value and get the result in SSRS report.
How to do that in SSAS Cube.
Thanks
Shashi

Hi ,
If I understand your requirement correctly , then you need currency Conversion.
you can refer this links.
http://consultingblogs.emc.com/christianwade/archive/2006/08/24/Currency-Conversion-in-Analysis-Services-2005.aspx
http://www.ssas-info.com/analysis-services-faq/27-mdx/244-how-change-currency-symbol-based-on-selected-currency-dimension-member
http://social.technet.microsoft.com/wiki/contents/articles/18672.currency-conversion-in-ssas-2012-multidimensional-tabular.aspx
May I know , You Require all this using MDX and SSRS Parameter ?
Thanks

Measurement and Automation explorer or the Instrument I/O Assistant is not installed correctly.

I am having difficulties getting Labview to work with my NI card. I have a PCI_6225 card running on a Win 7 64-bit install. I had to download all of the drivers and installers from the NI site and during the Labview install, I recieve a prompt asking for my hardware drivers. Since I only have the compressed hardware installer, Labview doesn't like what it sees and continues the installation of LABVIEW. I then attempt to open an analog input channel through the Instrument I/O Assistant which displays the error seen in the image attached.
I know the hardware works because in the Measurement and Automation client, I am able to observe the analog input I hope to collect in LABVIEW.
Is there a fix to get LABVIEW working? I have tried multple installs of LABVIEW and am on a administered computer through my University's IT people. I have 'full admin' rights. Thanks.
Attachments:
error.jpg ‏254 KB

Hello jbaxter,
When you download the Drivers from NI's website, make sure you unzip them (extract them) to a folder on your computer before you install them. If you use the NI Downloader it should prompt you to unzip and run the files after the download is complete. You need to either repair, or reinstall DAQmx and NI VISA. Make sure you download the latest versions of these first:
http://search.ni.com/nisearch/app/main/p/bot/no/ap/global/lang/en/pg/1/sn/catnav:du,ssnav:sup/1//en/...
Then go to Control Panel»Programs and Features»National Instruments Software and click Uninstall/Change then go to DAQmx and NI-VISA and click Repair. You can then point to folder that you downloaded from NI's website (make sure this is not a zip folder, but the folder that has been extracted). Or you could choose Remove, and then reinstall them both again. Also if you are using GPIB, reinstall or repair the NI-488.2 driver.
Here are some relevant links:
http://digital.ni.com/public.nsf/allkb/DC808866AF7D5C0986256FCE006E9BAB
http://forums.ni.com/t5/LabVIEW/Again-I-O-Assistant-not-installed-correctly/td-p/1024807
http://forums.ni.com/t5/Instrument-Control-GPIB-Serial/quot-MAX-or-Instrument-I-O-Assistant-not-inst...
http://forums.ni.com/t5/LabVIEW/Install-Instrument-I-O-Assistant/td-p/1471516
Software Developer
National Instruments

How to measure and plot RMS value of real time data?

hi
i need to measure and plot real time RMS value of EMG voltage. I made a VI. But I dont know why it didn't work. Can anyone please help me out? My VI is attached in 2013 and 2011 both version. One sample data is also attached. Thanks at advance.
Solved!
Go to Solution.
Attachments:
RMS.vi ‏47 KB
RMS_2011.vi ‏41 KB
Sample Data.docx ‏20 KB

You seem to select EMG voltage vs Angle(Z-axis). Is that really what you want? More resasonable would seem e.g. EMG voltage vs. time.
If you want to process the 3D (xyz data), you probably need to add some more math). Why are you taking the absolute value? RMS does not care about the sign anyway, right?
They you are trying an XY graph with a single point, because your Y value is only a single number. You need an equal number of points for Y.
Here's a quick modification that graph EMG(mV) vs. time(ms) and takes the RMS of the EMG data. See if this gives you some ideas.
Please provide more information what you want to do with the angles.
LabVIEW Champion . Do more with less code and in less time .
Attachments:
RMS_MOD.vi ‏18 KB

Scale in Measurement and Automation

Hello,
I have 50 load cells. When loaded, they give Voltage values. But I want the results directly in load values( i.e., in kilo Newtons). I have 50 different conversion factors (one for each load cell) written in a text file. How do I use the "Scale" option in Measurement and Automation Explorer to convert voltages to loads so I get load values directly ? Below is the step-by-step description of my problem.
My problem:   I am getting 50 voltage values ( V1, V2, V3...........V50)
                       But I want them in terms of kilo Newtons (kN1, kN2, kN3......kN50)
                       I have 50 multipliers that can do this conversion (m1, m2, m3.....m50). They are in a text file.
                       All I need is kN1 = V1 * m1, kN2 = V2 * m2 and so on.
How do I this scaling operation ?
Thank you very much in advance for your kind help.

Thanks very much for the reply.
Attached is my code. It measures votages (upper left side of the code) and it also reads the multiplying constants from a text file (lower left side of the code). Then using the 'for loop' at the center, it converts the voltages to loads and finally it writes the load values in a file (middle left of the code, path labled as SC1).
Is my code efficient ?
Someone told me such code will slow down the entire process because of the loop. He suggested that I use "DAQmx create scale" and "scale node" to write a more efficient code. I don't know how to do that.
Can someone help me on this, please?
Attachments:
Learning-2.vi ‏42 KB

Measure and Record Temperature and Pressure

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