Data acquisition in automotive crash test

I need information about hardware and software NI tools for develop a data
acquisition system

NI has a very broad range of tools that would fit this type of application. Identifying which tools will fit your needs will require a more indepth specification of system parameters. I highly recommend that you use the on-line DAQ Designer at http://www.ni.com/daq/ddonline.htm. If you prefer you can also enter a conversation on-line by following the "Ask an Expert" link at the bottom of any on-line catalog page.

Similar Messages

Does anyone know how to display (in LabVIEW) the memory use during execution of an image and data acquisition VI to predict when it is time to cease the acquisition to prevent the program crashing?

Does anyone know how to display (in LabVIEW) the memory use during execution of an image and data acquisition VI to predict when it is time to cease the acquisition to prevent the program crashing?
I am acquiring images and data to a buffer on the edge of the while loop, and am finding that the crashing of the program is unpredictable, but almost always due to a memory saturation when the buffers gets too big.
I have attached the VI.
Thanks for the help
Attachments:
new_control_and_acquisition_program.vi ‏946 KB

Take a look at this document that discusses how to monitor IMAQ memory usage:
http://digital.ni.com/public.nsf/websearch/8C6E405861C60DE786256DB400755957
Hope this helps -
Julie

Immediate Small Project - Test Bench Data Acquisition, Processing, & Basic Automation

I am need of a Labview Programmer to assist immediately on a test bench setup. The sepcifics are as follows....
Acquire data from 16 LVDT with 4-20 mA signal simultaneously at a single time.
Convert to distance using bit resolution conversion.
Calculate best fit plane for data points, given a (x,y) location of each sensor, where the signal is the z coordinate.
Calculate properties of part with distance from best fit plane to individual LVDT points and report to LabView SPC.
Trigger 24 VDC I/O to actuate pneumatic solenoids with timing delays to provide throughput through test station.
Trigger data acquisition when part is present in test area of machine.
Requested completion time is one week. Project is located in Clover, SC outside of Charlotte, NC. Remote work is acceptable.
Please email me if interested in project. [email protected]

I am need of a Labview Programmer to assist immediately on a test bench setup. The sepcifics are as follows....
Acquire data from 16 LVDT with 4-20 mA signal simultaneously at a single time.
Convert to distance using bit resolution conversion.
Calculate best fit plane for data points, given a (x,y) location of each sensor, where the signal is the z coordinate.
Calculate properties of part with distance from best fit plane to individual LVDT points and report to LabView SPC.
Trigger 24 VDC I/O to actuate pneumatic solenoids with timing delays to provide throughput through test station.
Trigger data acquisition when part is present in test area of machine.
Requested completion time is one week. Project is located in Clover, SC outside of Charlotte, NC. Remote work is acceptable.
Please email me if interested in project. [email protected]

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 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.

Data acquisition loop with queue

What I would like to do is have a data acquisition loop that samples a load cell at 500Hz and have another loop that runs much slower to run a state machine and display some data in real time. The reason I want to sample the load cell so fast is to filter out some noise. Making producer/consumer loops with a queue kind of makes sense but I don't really care about all of the samples, I just want to be able to read a real time filtered signal at certain times. I looked at having just two parallel loops, one to acquire the data and the other to run a test and retrieve a real-time signal when I want but not sure how to pass data between the loops without using a queue. You can do it with local variables but you are at risk of a race condition. I hope this make sense. I am sure this is a simple problem I just don't know what direction to go. Thanks

Good Evening secr1973,
It sounds like you are on the right track. You already know about the producer/consumer architecture; this is almost always the first step to the separation that I think you are after.
The step that I think you are missing is a Case Structure around the enqueue element VI. You likely have some event or specific pattern that you are looking for in the input signal. You can have the output from this algorithm (likely a boolean) determine which case of the Case Structure to execute (Case 1: enqueue the element or Case 2: Do not enqueue the element).
This, of course, leads to processing being done in the producer loop, which is quite the opposite of what you are trying to accomplish with the producer/consumer architecture. You will have to decide if your processing is very simple or more complicated.
If it is easy/fast, you can likely get away with doing this processing in the producer loop. My guess is that your program falls under the category of do-it-all-in-the-producer loop because you are only acquiring at 500 Hz.
If the application requires faster acquisition rates or if the logic is going to require some processing, you may want to implement a double layer producer/consumer architecture. In this setup, you would pass all of the data from the DAQ producer to a second loop (using queue #1) that determines what to do with the data (to enqueue or not to enqueue...) and, if appropriate, write to a queue (queue #2) that the third loop can read. The third loop would be where your state machine executes.
If you have a quad core machine, each of these steps will execute on its own core. If not, you will have a little more thread swapping; not a huge concern in most cases. Here, we get into the art of programming more than the science.
In any event, I think you will be OK with a little processing for the enqueue or not algorithm in the producer loop.
Regards,
Charlie Piazza
Staff Product Support Engineer, RF
National Instruments

Data Acquisition Step Type

Hi, is there a step type to perform Data Acquisition and Basic comm control such as RS232 and GPIB within teststand ?
This question was raised when I was training one of our Technicians today, he asked/suggested that having a step type which performs Data Acquisition and comm control would reduce there development time down dramatically, They have just started to use Teststand on small cycle test rigs as part of an evaluation stage. They have no experience with LabVIEW or CVI, they basically want a quick and easy way to produce a test sequence with Data Acquisition and comm control.
if there is anything like this at the moment can you possibly reply. If there is not, is this a something which will be avaible in the future ?
Message Edited by ds1638 on 12-09-2008 02:44 PM

Data Acquisition usually refers to a DAQ board from NI so I think what you are looking for is a generic NI-VISA step type and a specific RS-232 step type. I have a NI-VISA step type that was originally written with LabVIEW 6.1 and for use with TestStand 2. I've atached that below. I don't have the .ini file handy and don't have time to recreate it but from the code, you should be able to see what needs to be added to the step properties. The basic step is a modified Pass/Fail Step.
It's not that difficult to create your own custom steps. I've done a lot and it only takes a little while longer than doing a code module in LabVIEW or CVI. The extra time is in creating the edit step.
I've got an RS-232 step type but part of it is product specific so it is proprietary and I can't post that. Look at the VISA example and the other examples of custom step types that are on the developer zone and see how far you get.
Attachments:
VISA IO.zip ‏188 KB

How do you cyclicly trigger data acquisition after n pulses counted

Hello all, please forgive my ignorance because I am very new
to lab view and data acquisition. I am working on a system which is going to
scan an object and produce an image. The gimble that I am scanning the object
with is an X-Y type of gimble with stepper motors on each axis. The stepper
motor controller will output pulses real time to indicate the real time
position of the gimble in each axis. What I need to be able to do is count
pulses from the stepper motor controller and then output a trigger pulse to
trigger the data acquisition in a buffered mode when N number of pulses have
passed and then generate another pulse to stop the acquisition after another N
number of pulses have passed. The controller puts out 10,000 pulses per degree
of travel. The velocity that I am traveling at is 20 degrees per second, so
timing here is really important. I need to be able to utilize the speed of the
daq card and not so much the speed of the computer to iterate through a loop. I
have tried using the count down feature in the NIDAQ MX library but it does not
appear to be useful to me. I set it up and it will count down but once it hits
zero it continues to count down. My expectation was that it would either
restart the down count or it would stop. I was expecting some sort of trigger
event to take place once the count reached the zero point but I did not observe
any sort of event taking place. Once again my knowledge and background is
really limited so I could be missing something really fundamental here. I have
tried using some of the legacy functions which would enable me to do exactly
what I want to do but they do not seem to work with my daq card. I have a NI
PCI-6122 and if anyone has any knowledge on how to get this type of card to
talk to some of the non MX functions I would be more than happy to hear how. It
seems to me though, that I am limited to the MX functions which I can not
really translate into what I have learned I can do with the legacy functions. I
thank you all once again for taking the time to read this I and I will
appreciate any and all responses that can be helpful.
~ Randy Brown

I have run a few more tests and obtained some data per the request of a telephone support engineer. I have some scope screen shots that might be able to shed some light on what is going on. I will provide a brief description of what I discovered before I show the resulting data. I discovered that using the number of up ticks and down ticks suggested does not yield the right timing for the clock pulses that I will need for triggering my data acquisition. When I use 55 low ticks and 2 high ticks as my settings I end up getting a pulse every 32 pulses read on the PFI line. I get the same results when I interchange the numbers, for example, when I set the program up for 2 low ticks and 55 high ticks I get the same resulting one clock pulse per 32 pulses on the PFI line. I started playing with the numbers and come to find that I was able to generate a pulse every 57 pulses in this setup. I set the high ticks to 2 and the low ticks to 71 and once I did that it generated a pulse every 57 pulses in. The results are not ideal though, a number of things happen within the first second of operation. One mode of operation the clock output pulse latches after a few pulses generated. Another mode of operation that I noticed was that it would generate n number of pulses and then just stop even though the program was still running. The results I am getting are not reproducible when it comes to the long-term operation of the clock pulse generation but the bottom line is not matter what happens the end result after 1 second is not what is expected. I will show below screen shots of my program and also scope shots for the respective modes of operation.
Front End interface
Block Diagram
55 High ticks and 2 low ticks results
55 low ticks and 2 high ticks results
77 Low ticks and 2 high ticks results
Undesired Latch after 1 second of operation
N number of pulses generated and stopped while program was still running
It appears the the long term operation (and when I say long term I mean after a second) is intermittent, it either latches high or low after a random number of pulses are generated on the clock output. I am not sure why this is happening. The one setup that I came up with that generates a pulse every 57 pulses is not going to work for the setup that I have I think I would have to reduce the 71 to 69 in order to compensate for the two pulses that happen while the output pulse of the clock is high. To be honest I have no idea what is going on and I am starting to wonder about my daq card. Being that it is not really reproducing the same results I am starting to think maybe something is wrong with it. Another possibility is that it might be the bnc 2110 that I am using. I will try another one tomarrow and see if this problem persisits. I am leaving now so I won't be able to try that as of yet but I wanted to pass this info and data along such that maybe you will notice something and be able to lead me in the right direction. Thank you again for all of your help.
~ Randy Brown

Data Acquisition VI

Hello,
I am a graduate student and new to labview program, I have spent my couple of weeks to learn about labview and data acquisition techniques in labview. So far I am able to code a program as attached (block diagram) which basically runs only at highlight execution mode. I need to run the program throuhout the test period and record all the datas. I have NI- SCXI 1001 hard ware device and 2013 labview. I need to read from multiple channel at a time though it seems to be doing with this code. The output as attached is also not clear. I want the output to be tabulated with topic like Load, Stroke, Potentiometer 1 and Potentiometer2 etc. Please all help me to solve this problem. Your suggestions are highly appreciated.
Solved!
Go to Solution.
Attachments:
block diagram.PNG ‏13 KB
front panel display.PNG ‏42 KB
out put2.txt ‏1 KB

Dear Dennis,
I have incorporated your comments and also revised from my side, now it is working little bit, I still wants to improve its functionality in the area of displaying graph, and time flexibility, please suggest me. If you have any informative links and documents regarding data acquisition please convey to me.
I have attached screenshot of block diagram for your kind information.
Attachments:
block diagram-27 march.PNG ‏20 KB

How to writing the data into the file at the same frequency of data acquisition using myRIO

Hi everyone,
I have a question regarding data acquisition fequency and data recording frequency of myRIO. Hope you guys can help me out.
Basically, I want to acquire voltage input at analog input 0 at the frequency of 1kHz and then write the data into a file (tdms format).
However, I always found there were only 55 or 56 data points recorded every second in the data file (see the excel sheet).
To confirm my data acquisition was performed at the correct frequency, I added a small function in the main loop to indicate the time spent between two acquisition events.
To my surprise, the period of data acquistion is correct (1ms or 1kHz) but there are only 55 or 56 data point per second recorded in the data file.
How can I record every data point acquired by the analog input?
Thank you!
P.S. I am very new to myRIO. How can I manually set the system time for myRIO? The default time of my myRIO is wrong.
Best,
Tengyang
Attachments:
test result.xlsx ‏16 KB
Main with timed loop.vi ‏122 KB
test result.xlsx ‏16 KB

Have a look at the Jakarta POI project, they have a Java API for creating Word documents.
http://jakarta.apache.org/poi/hwpf/index.html

Scheduled data acquisition

hello
every body
my task is scheduled data acquisition. which is the efficient method to do that,
for example
i want to start the acqusition in the morning 9.pm and finish at 10.30 p.m and save the data in a file and wait for next acquistion it starts at 11.p.m and end at 12.30 p.m . like that i want to do.where the start time and end time i will give in a data file ok.
by continously watching the system clock i can do but . can u give some efficent method of doing that.
Indrajit
| [email protected] | [email protected] .

First, a couple of questions.
Are you running on a windows platform
Are you building an EXE?
I am sorry I am late to respond, but I needed to test this before I recommended it. If the answer to 1 is yes, you can use the windows task scheduler to launch your app and make your acquistion. If the answer to 2 is NO, then your cmd line switches will need to be a -- instead of whatever you like. You can read a file, if need be, to determine the length of the acquistion. The biggest benefit to this approach, is that you can have the system run this task, even if you are not logged in! Usually IT hates it when you leave domain computers logged in! And best of all, NO system resources are spent, no background app is running, and consuming whatever resources are required. Granted, there are not much given the suggested approach, but yet another app (one with a front panel open somewhere) running. I do not know about you, but I try to minimize the number of processes running at any given time. I have tested this, and even brought my computer out of hybernation and sleep modes to run the app! That is fantastic. I hope this helps.
Paul <--Always Learning!!!
sense and simplicity.
Browse my sample VIs?

How to use peak detection in labview to detect peaks from data acquisition information

Hi
I am a university engineering student who is working in a team to develop a coin detector, its purpose is to recognize different coinage and detect fakes.
For this we are using LabVIEW 8.5.1. I am relatively new to labview and have had no experience of using to before. We are trying to integrate four voltage signals produced by an electromagnet, straingauge, optical sensor and a proximity sensor. We have already developed signal conditioning for these tests and now wish to put them into labview.
Our plan is to use peak detection on each of the tests so that labview can detect peaks which correspond to different coin types, provided they meet set criteria for each coin. Then to combine these either using logic or mathscript to produce a Boolean output for each coin.
One of our advisors helped us develop a peak detection program for a simple simulated sine wave however we are struggling to adapt this for data acquisition information and itegrate it with mathscript and to be honest it does not make much sense. I have attached the program below. Thanks in advance for your assistance.
Attachments:
Strain 2.vi ‏25 KB

Chris,
Here are several ways to help you get started with peak detection:
1. On your functions palette, you can search for "peak detect" and you'll find several different variations of VIs that will do peak detection.
2. You may also want to take a look at this tutorial: Peak Detection Using LabVIEW and Measurement Studio
3. There's an example in the example finder called "Peak detection and display" that will probably be useful.
Hope this helps,
Misha

Can I develop a data acquisition app without the DAQ card installed?

I'm new to LabView.
I would like to build a simple data acquisition app (graphical display and logging). I would prefer to build this on my desktop, and then install/run it on a laptop.
I'm not sure how to work this as the DAQ card and driver are not installed on my desktop. Is there a (hopefully) simple way to configure a data source in labview so that the app will automatically (or at least easily) connect to the existing driver?
At the end of the day I don't want to install the complete dev system on my cheap little laptop just for this one application.
TIA,
Michael

yes you can develop an application without having a daq card installed. You still will use the same functions in labVIEW. If you are using labVIEW 6.1 they are under the data acquisition palette in the block diagram. If you are using LV7 there are now two types of data acquisition functions. Traditional NI Daq (before lv 7) and new Daq MX. The daq functions are under the NI Measurements palette in LV7. If you are new to LV I suggest you use the daq assistant on the bottom of the palette. This will allow you to easily configure what you want, the drawback is that you will need to use this on the computer that has the card. So try the traditionaly nidaq functions. They will allow you to develop without the card. hope this helps.
BJD1613
Lead Test Tools Development Engineer
Philips Respironics
Certified LV Architect / Instructor

Problem with Real Time Data Acquisition

Hello,
I tried to built a RDA data flow according to the SAP-Help and this blog (/people/kamaljeet.kharbanda/blog/2006/11/13/real-time-data-acquisition-bi2004s), but I ran into a problem. Everything seems to be fine, but even though the daemon is running no new data is added to the DSO. I'll explain in detail what steps I took and hope someone can pinpoint my error(s).
System is BW4 on SPS 17. My datasource as well as my DSObject are in the same system
1.) Created a transparent table with a timestamp-field for generic delta as a local object.
2.) Created a generic datasource from view/table (used the above table), marked it as realtime-enabled and used timestamp as delta-specific field.
3.) Replicated the metadata for my datasource and activated it.
4.) Created a Data Storage Object with infoobjects corresponding to the table fields
5.) Created a transformation between DataSource and DSO
6.) Created a DTP from Data Source to DSO. The type is realtime-DTP.
7.) Created an InfoPackage for Delta-Initial Load. Update mode: Initialize Delta Process -> Initialization with Data Transfer.
8.) Then I changed my DTP (step 6) to "normal DTP" and executed it. Then activated the data in the DSO. The datasets from the table (which i filled with an ABAP-program) were successfully loaded and activated. So now my DSO contains 5 datasets.
9.) Changed the DTP back to "realtime DTP"
10.) Created an InfoPackage for RDA. Adapter is set to "Realtime extraction from SAP System"
11.) Created a daemon, assigned the IP for RDA and the DTP to the daemon and started it up.
12.) Executed my ABAP program to added 3 datasets to the table which is used as a datasource.
So now in my source table there are 8 datasets, but the daemon won't load them. In my RDA-Monitor (trx rsrda) it shows my daemon, the assigned IP and the assigned DTP (status green). Under the IP there's one yellow request (that should be right according to the help), but unlike the picture in the blog (link see above) there's no request under the DTP.
Job overview (sm37) shows an active batch job and some jobs that are ready (every 10minutes a new batch starts and the old one is closed). the job log shows, that the daemon runs, but loads no data...
i think it might be a problem with the delta extraction somewhere, because the intial load works fine and there are no errors anywhere.
Edit: perhaps my settings in the data source unter tab: extraction are wrong?
Delta process: AIE After Images By Extractor (can't change that)
Direct Access: Allowd
real Time: Real-Time DA Supported
Adapter: realtime data extraction (also tried Access to SAP Data through Service API which seems senseless)
Data Format: Fixed Lenght
Anyone can explain what those fileds mean and which one i should use?
Edited by: Christoph Jender on Apr 10, 2008 2:48 PM
Edited by: Christoph Jender on Apr 10, 2008 3:33 PM

Hi again, another thing i'd like to try is to just active a business content datasource which is realtime-enabled and has the ability to dynamically add some values so that i can test if it works. but i have no idea what business content would be applicable here, any ideas on that perhaps?

Data acquisition in automotive crash test

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