Resetting Data Acquisition

I have a data acquisition vi that uses the express DAQ assistant express vi. with data in 'continuous acquistion' mode. The data looks fine. The user can then choose to average the data and plot it or save it. Once the save function is completed, the vi loops back to the 'live' mode. Now, there is a large DC component in the fft, even though there is a 5Hz highpass filter on the data.
I have seen past discussions on resets that are required to eliminate this 'step' discontinuity' but I can't seem to find it now that I need it.
Thanks in advance,
Ron

Use the Queue functions to send the data to another VI that will save the data while the DAQ VI stays in live mode.
Using VI's in parallel loops will allow the data collection VI and the data processing VI to run independently of each other.
Here is a quick link to the Queue example that is included in LabVIEW. You can also find it by using the "Find examples" under the Help Tab.
CLD | CTD
LabVIEW 2011 SP1 | TestStand 4.5
Attachments:
Queue Basics.vi ‏22 KB

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Stop and reset data acquisition

I have a vi that takes raw vibration signals and filters, integrates and then displays. The user watches the live display and then when ready clicks on the 'acquire' button. The data is averaged and saved. The user is then asked if they want to acquire more data. My problem is when the 'live' screen comes back, there is a huge curved slope. How do I reset the data acquisition?
Ron

Your problem is that your buffer han been filled up and overflowed while waiting for user to deside what to do. This problem can be solved if you do a "dummy read" with the number of samples per channel input unwired or set it to -1. If the task acquires samples continuously and you set this input to -1, this VI reads all the samples currently available in the buffer. Do the dummy read then you leave your saving routine. And you will start with a fresh buffer in the "live" screen. After all your application is a continuously reading type application
Besides which, my opinion is that Express VIs Carthage must be destroyed deleted
(Sorry no Labview "brag list" so far)

Problem in data acquisition

Regarding to my project I have implemented a LabVIEW program which is doing data acquisition. We have LabVIEW 6i Installed in PXI-8170. The DAQ Card that we use is NI6030E DAQ Card Multifunction I/O.
I have implemented a VI to acquire and plot and record multiple analog input channels. By using AI Acquire Waveforms VI to acquire waveforms from 4 channels in a single run and using Index Array function to extracts the data for each channel.
For plotting waveforms, I use waveform chart for each channel. I put all this functions in a While Loop and use a stop push button to stop the acquisition. I also put another push button named Save to disk in the loop that by pressing it we can save data to a File by using Write to Spreadsheet File. VI, located in a case structure out of the while loop. I save data as a 2D array by connecting the waveforms output connector of AI Acquire Waveforms VI to the input connector of Write to Spreadsheet File VI.
But I have some problem that I can not solve it yet which are listed below:
1- I want to record all the data that I acquire for a specific time, but I can not. I only can save the specific part of the waveforms which I think it is specified by the number of samples/ch and Scan rate controls.
For example I do the acquisition for about 1:30 minute and save it, but when I plot the data which is saved in the spreadsheet file; it is only the last 20 seconds. So I can not save all the data that I try to acquire.
2- I want to record data for a specific time automatically. I mean when I run the VI after press the Save to disk push button the VI automatically start saving data for a specified period of time and then automatically stop. (How to define a timer to control the VI?)
3- I want to start acquisition each time from zero base time. I mean when I do the acquisition for the first time and then I want to do it for second time, the pervious acquisition reset or clear and the time axes of each chart again start from zero not continue the pervious time. It means that I need to clear the chart.
Regarding to this problem I try to use the AI Clear VI, but it didn�t work. May be I don�t know how to use it.
Attachments:
test4chPPG1.vi ‏49 KB

I need your hints about these 3 problems.

Z600 workstation missing pci data acquisition and signal processing controller driver

I just installed Win7 Pro x86 on my Z600 workstation. It was an upgrade from WinXP Pro. In Device Manager I am missing the driver for the PCI Data Acquisition and Signal Processing Controller and Hardlock USB 1.02. Can someone assist me in finding these drivers. I looked on the Support/Drivers page for this model but couldn't find anything.
This question was solved.
View Solution.

Hi,
You might get better assistance on the HP Enterprise Business Forum since you have a professional worktsation.
HP DV9700, t9300, Nvidia 8600, 4GB, Crucial C300 128GB SSD
HP Photosmart Premium C309G, HP Photosmart 6520
HP Touchpad, HP Chromebook 11
Custom i7-4770k,Z-87, 8GB, Vertex 3 SSD, Samsung EVO SSD, Corsair HX650,GTX 760
Custom i7-4790k,Z-97, 16GB, Vertex 3 SSD, Plextor M.2 SSD, Samsung EVO SSD, Corsair HX650, GTX 660TI
Windows 7/8 UEFI/Legacy mode, MBR/GPT

Driver missing - PCIe Data Acquisition and Signal .....

Hello, i recently used Boot Camp to install Windows XP on my 2010 15" Macbook Pro.
All the drivers are working (so far) and i haven't encountered many problems.
However, there is one thing bugging me:
When i go into Device Manager in Windows, and look down the list of installed/uninstalled devices, there is a device called "PCIe Data Acquisition and Signal Processing Controller" which has no driver installed.
I'm PC savvy, but i have never seen this before. My guess is that one of the motherboard drivers is missing, and Boot Camp installer doesn't include that driver?
Has anyone seen/resolved this, and if so, how?
Thanks.
Kaj.

Okay, will do.
Thanks.
Also i wonder if you could help with another problem?
http://discussions.apple.com/thread.jspa?threadID=2758766&tstart=0

PCI Data Acquisition and Signal Processing Controller driver

I've installed win 8.1x64 on my HP Probook 450 G2 but I am missing the PCI Data Acquisition and Signal Processing Controller driver.
Can you please help?
Thanks,
Leontina
This question was solved.
View Solution.

Hi:
Please see if installing the Intel Chipset driver installs that device.
https://downloadcenter.intel.com/Detail_Desc.aspx?DwnldID=20775&lang=eng&ProdId=816

Pci data acquisition and signal processing controller -Device software not installed

My pc shows me ,the driver software for pci data acquisition and signal processing controller is not installed on my Device manager.
Please suggest me a suitable solution.

No its not working , Give me an alternate solution.

Data acquisition from SR 530 lockin

Hello,
I need to read the output of the sr530 vector lockin and store them in a file.
I was wondering if there is any driver which will let me read frequency, output amplitudes & relative phase between the input & output signal!
Any help will be much appreciated!
Thanks a lot,
Ashutosh.

Thanks a lot for the help Matt.
I can connect the device via GPIB. Let me tell you a bit more about the problem. As of now I was using a single channel lockin, EG & G 5209, to read the data(so I am kindda familiar wtih data acquisition... not much though). And the only thing I was reading was the output amplitude of the lockin.
Now I have to use the vector lockin, SR 530, and I will need to read both the output amplitudes, the phase & the frequency (all four of them)at the same time. And I am looking for a driver which can do this, i.e. which can read all four data simultaneously & store the result in a *.txt or *.dat file.
Do we have something like that?
Thanks,
Ashutosh.

Data acquisition in a state machine

I've recently learned how to implement state machines, but I have a question that I haven't been able to find an aswer to.
Question:
How do I record uninterupted data (presently i'm using the DAQ assistant to record a single channel at 10kS/s at 1kS intervals) without interfering with my state machine?
Background:
I have a time sensitive test setup (measuring pressure in a rocket chamber), and I'm using labview to both record a single pressure transducer as well as operate the valves (O2, N2, igniter, etc). I'm using a state machine Labview architecture (just learned how). Presently, the DAQ assistant sits in the "Idle" state, and timers (valves need to be turned on at specific times) and manual buttons control when the other states are activated. I have a 10ms timer controlling how often each state is run, and this is the root of my concern.
Main concerns:
I'm worried that:
1) I'm forced to change my data recording to 10ms intervals to match the 10ms timer, and
2) The 10ms timer will interrupt my data recording when it's in another state.
It's very important that the pressure data is recorded without interruption but that I have high time resolution in controlling my valves as well.
Thoughts:
1) Maybe I put the 10ms timer in the "Idle" state only, and this way the other states won't interrupt the data acqusition
2) Maybe there is a way to completely isolate the state machine for controlling the valves and the data acqusition. I'm not sure how to do this.
3) People on the forums have been talking about Queuing their data acqusition, but I'm not sure how this would benefit my situation.
Thanks to everyone for their feedback!

The data acquisition and state machine timer do not have to be equal, you should however have the same data write rate as you have data read rate, otherwise over the course of long running programs you can build up a large buffer of data to be written using a lot of memory, or lose data.
Your data acquisition should be continuous, the most common way of doing this is every time you receive data write it to a queue, then when you are in other states except your data write stage you simply build up data in the queue that is to be written when you enter the write state again.
Think of it as traffic reaching a set of lights:
The traffic represents the data acquisition, there is a constant flow of it always coming through, the state of your state machine is the lights, green is the data write state clearing the queue, red is when in any other state, letting the traffic build up behind the lights.
It is just important that the light is green long enough to let the traffic not build up too much, otherwise you have a jam.
EDIT: For the basics of how queues work, look at the Queue basics example from the example finder.

Data acquisition from multiple channels.

Hello
Right now, I am able to acquire the signal from a single load cell and display it.But I would like to know of how to acquire acquire signals from two load cells simultaneously.I am using Labview 6i and I am using AI S-Scan with AI config to acquire the waveform.It would be of great help if you could suggest a simple method to acquire the signals.
PS: Please find the attached file used for acquisition from a single load cell.
Looking forward for your reply.
Manasa
Attachments:
test 4.vi ‏102 KB

Hi Manasa,
If I understand what you are trying to do, it is relatively
straightforward to configure your application to acquire data on two channels.
I was unable to run your vi as it was missing some of the subVI’s
from your application. However, your
attachment was sufficient to see what you are trying to do.
Here is how to add channels:
1.
In the I/O Channel Constant, you can add
additional channels by using a comma or a semi-colon. For example, to scan the first four channels
you would put 0:3 in the constant (see attached screenshot ChannelConfig.jpg). To scan the first and third channel you would
put 0,2.
2.
The AI Single Scan VI will now read from
multiple channels. Often it easiest to
configure the output of this VI for viewing by first putting the data into an
array using the Build Array VI. It can
then be plotted in a waveform graph. (see attached screenshot ReadtoGraph.jpg
and WaveFormGraph.jpg)
Just a few notes about “simultaneous” sampling:
Most of the NI data acquisition cards have a multiplexer
between the various input channels and the Analog to Digital (A/D) converter
creating a very small delay between each channel (usually ms range or
smaller). NI does make several data acquisition
cards that can perform true simultaneous sampling, meaning that there is an A/D
converter for each channel.
For the large majority of applications, the small delay
between channels is negligible.
Jared T.
Attachments:
ReadtoGraph.JPG ‏21 KB
ChannelConfig.JPG ‏288 KB
WaveFromChart.JPG ‏61 KB

Data acquisition from switching 500lbs load cell to 100lbs load cell

I am using 500lbs load cell, and acquiring data by inputing 2volts from 2345 signal conditioning board, and sensor output is connected to SCC-AI03 pin 3 and 4 , and configure this load cell to a channel using NI MAX, data neighborhood, traditional NI-DAQ virtual channel, the physical quantity is voltage set at range -10 to 10, and sensor also set at voltage with no scaling, but, I couldn't get any signal when 100lbs load cell is use, the difference of this 100 lbs load cell is the rated output is at 2.958mV/V, while the 500lbs rated at 1.8295mV/V , how should I do this?
Thanks.

Hi,
At this point, it is difficult to determine exactly what is happening to your acquisition. Could you please provide some additional information by answering the following questions:
What voltage are you reading with the 500 lb load cell?
Would it be possible to connect your load cells to a DMM and see what voltage reading you receive? If so, what do you see?
What is specifically happening when you connect the 100 lb load cell?
I also noticed that you are using the Traditional NI-DAQ (Legacy) driver. I recommend upgrading to the NI-DAQmx driver. Here are a couple of links with more information about DAQmx:
Advantages of NI-DAQmx:
Transition from Traditional NI-DAQ to NI-DAQmx:
Learn 10 Functions in NI-DAQmx and Solve 80% of Data Acquisition Applications:
Regards,
Hal L.

Data acquisition driven by encoder

Hi everyone,
I need to sample a capacitive sensor that measures the radial run-out (radial small displacement) of a rotating spindle. LabView v. 7.1 is employed to acquire the data by means of PCI-6036E card commercialized by National Instruments (NI). The spindle rotates at 100 rpm and a rotary incremental encoder is fixed at rear of spindle. The encoder gives two types of digital pulses as follows: a) A-quad-B pulses (it will be used only “A” pulses in this experiment); b) index pulse (one pulse per revolution). This encoder provides 1024 pulses type “A” per revolution. The measurements made by the sensor are driven by “A” pulses which are used as “external clock”. Therefore, every “A“ pulse, the card acquires one sample from sensor. Thus, 1024 data/rev are acquired. I want to sample 5 consecutive revolutions of the spindle. To start the data acquisition, the index pulse of the encoder is used as “start digital trigger”. Also, the index pulse should be used to count the number of revolutions of the spindle. In this way, when the number of revolutions is equal to 5, the data acquisition finishes. By contrast, the programmer also can set the number of samples equal to 5x1024 in the VI. The data acquisition is finished when the number of samples reaches this value. Similarly, the sampling process is started by the index pulse which is the “start trigger”. Note: 1) the sampled data should be put in a buffer. After the sampling process is finished, this data should be saved in a file of LabView; 2) In fact, the data acquired by the sensor are voltage analog input. Questions:1) Could you make a VI for this problem, please? Note: You can use the DAQ ASSISTANT EXPRESS VI or DAQmx TASK NAME CONTROL method.2) How to program the LabView in order to sample data triggered by the rotary encoder (pulse “A”)?3) What should I do to stop the data acquisition at the end of 5 revolutions?4) Could you send examples (VIs) similar to my problem above?5) How can I know if the program (VI) looses an “A” pulse? Is there any kind of error in VI that indicates a miss pulse? In anticipation, thank you very much for any help. My e-mail: [email protected] Bruce

Hello Bruce,
I have a complete solution for this but I cannot give you the VIs because my customer has paied for it and all rights are transfered to him.
What you need are two tasks. One task is the analog in task. You must use the DAQmx Timing.vi and the DAQmx Trigger.vi to set it up as needed. Or you create a task in MAX with this setup. The other task is a counter task just counting the pulses from the z-Index.
Next you need a small state machine with the states:
init, start, wait and stop.
init will initialize and start the tasks
start will read out the z pulse counter and wait for a change from 0 to 1
wait will read out the z pulse counter or the available samples property, when the desired number of z pulses or samples are available read the buffer with DAQmx Read.vi
stop will stop both tasks and clear them.
You will need two additonal counters which you don't have to check for lost A pulses and a external flip-flop electronic. The flip-flop will change it's state with each z pulse and the output will be used for gated counting. With each change of the z pulse counter you need to read out one of the additional counters to check if he had seen the correct number of pulses.
Waldemar
Using 7.1.1, 8.5.1, 8.6.1, 2009 on XP and RT
Don't forget to give Kudos to good answers and/or questions

Data acquisition on the basis of time

Hi everyone,
I want to acquire the radial run-out (radial small displacement) of a rotating spindle using a capacitive sensor. To do so I will use the LabView v. 7.1. The PCI-6036E card from National Instruments (NI) will be utilized for data acquisition. The spindle turns at 100 rpm and a rotational incremental encoder is fixed at rear of spindle. This encoder provides an index digital pulse per revolution. This pulse should be used to start and finish the sampling process. I want to sample on the basis of time, by means of sampling rate of the card (Ksamples/s). So, let us suppose that I want to acquire 500 data/rev. The spindle takes 0.6 sec to complete one revolution. Thus, the required sampling rate is Fs = 500 samples/0.6 s = 833 samples/s. So, I should set the VI in LabView so that it samples only 833 data/s. Therefore, I will have to reduce the sampling rate of the analog-input channels in use. For example, let us suppose that the card provides 100 Ks/s when operating in multiple channels. Let us admit that there are 4 analog-input channels in use. So, the scan rate per channel is 25 Ks/s. This is too much for this application. I only need 833 samples/s. So, I should program the VI so that the card provides that required sample rate. As said earlier, I need to start and end the sampling process at the same point. Thus, to do that the index pulse of the encoder will be used. Also, I want to sample during 5 consecutive revolutions of the spindle. So, by means of a loop in VI, I should count the index pulse of encoder until the number of pulses be equal to 5 (= number of revolutions). At this instant, the sampling process should be stopped. Note: 1) the sampled data should be put in a buffer. After the sampling process is finished, this data should be saved in a file of LabView; 2) In fact, the data acquired by the sensor are voltage analog input. Questions:1) Could you make a VI for this problem, please? Note: you can use the DAQ ASSISTANT EXPRESS VI or DAQmx TASK NAME CONTROL method2) What should I do to stop the data acquisition at the end of 5 revolutions using the index pulse of encoder?3) Could you send examples (VIs) similar to my problem above? In anticipation, thank you very much for any help. My e-mail: [email protected]
Bruce

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Message Edited by smercurio_fc on 11-14-2008 09:10 AM

Data Acquisition for Position Transducer

I just purchased an Analog Position Transducer from SpaceAge Control, and was wondering if anyone had any code to gather the data. I must admit i'm lost when it comes to this, I thought the transducer would come like an instron where you just plug it into the computer. I have a six pronged plug that exits the device. I have a couple TI data acquisition boards at my disposal. I am hoping someone has used a similar product or has some advice. Thank You
Keith

We have lots of code to gather data in all sorts of ways. Building measurement applications is what we do. Since you are lost when it comes to this, you would do well to hire a guide in the form of an Alliance Member company. We do this stuff every day.
Your TI DAQ boards may do the trick, but you would have to show someone the specs for them. Also, you need to think about what kind of speed you require and where you want the position data to go. Table? Plot? Database? A good LabVIEW developer can set you up with some code that does exactly what you want.
Daniel L. Press
PrimeTest Corp.
www.primetest.com

Data acquisition from NI PXI 5152 using LabVIEW

Hi,
This might be really stupid question, I am new to LabVIEW and the Digitizer equipment. I was wondering if there are already any labVIEW based application available to read the data from PXI5152. I would be using both channels available and may be trigger. If there is no such application available, what would be port numbers I would be using for data acquisition. But, If I am to develop an acquisition software, I would be looking at every single specification of the equipment. I am assuming the output will be a digitized signal varying with the clock input, since It is used as oscilloscope. When working with labview how would I specify the port to read from and how would my PC recognize the port. I working on a pre-configured system and they won't let me unplug anything to check the configuration. Does NI provides a software to read into the signal fed into the channel and trigger inputs. I have tried looking into the different forum discussion but didn't find any that address my issue. May be it's too simple and stupid. But, it would be a great help if you could point out my misunderstanding.
Thanks in advance.
BP

There are numerous examples. Help>Find Examples> Modular Instruments>Ni-Scope. There is a test panel available in MAX. On the Measurement I/O>NI-Scope palette, are all of the driver functions includeing the NI-Scope Express.
I'm not quite sure I understand your references to 'port's. Once installed into the chassis, it should be listed in MAX. In the functions you will be using, there will be a dropdown menu that you will be able to select the scope resource name.

Resetting Data Acquisition

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