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NI-DAQ reading accelerometer - seems to choke up following addition of savitzky golay filtering

May 17, 2018, 11:11 am
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Hi all,

 

I have a program I have written to read continuously in a while loop from an accelerometer using NI-DAQ VIs.

 

The program is a bit complex but basically, after a 'no movement' baseline period, I want to see when acceleration goes over a threshold (i.e. a large enough movement occurred) this will trigger a sound, run for a few more seconds, then stop reading the accelerometer (I also log the data, and do some calculations on it after accel has stopped).

 

This was all working fine until I added a savitzky golay filter to smooth my signal. Now, everything works some of the time, but other times I can tell something is wrong as it starts going very slowly or will terminate the recording when it shouldn't (i.e. when no movement trigger has happened to stop it).

 

I presume maybe the filter is overloading some computational capacity, but I am not sure how to tell - as the error is quite erratic.

 

I am new to labview [first program] so I can't *really* understand what is wrong from looking in debugging mode, or anything else I tried. Would anyone have any ideas what is up? Big apologies in advance also - I know my code is certainly not the most efficient, or pretty. I know I should be using sub-VI's to make everything neat but while I am still writing I like to see everything in front of me.

 

Any help would be very very much appreciated! VI is attached (and the .wav file it plays)

 

Thank you!

Harriet

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how implement ease algorithm in servo motor

May 17, 2018, 11:14 am
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Resetting Values with Property Nodes

May 17, 2018, 11:47 am
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Hello all,

 

My front panel has quite a few indicators....let say about 20. While most are numeric, some are also text or Boolean. I use property nodes for each one to reset them before and after VI execution. All like indicators are set to the same value.  

 

It looks very busy on my block diagram because I have a property node for each individual indicator. Is there a way to batch all like indicators together in one property node? If there is, I haven't found it. It may not exist and the cleanest way my be by using one of the structures.

 

Thanks,

Ryan

 

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Thermocouple and SCB-68

May 17, 2018, 11:48 am
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I'm looking at a colleagues code on a teststation.  He is using a Type J thermocouple tied into a scb68 connector 0 on a PCI-6229 DAQ.  He configured the daq correctly in MAX...connector 0 has an accessory w the thermocouple box checked.  If I look at the scb 68 specs it looks like I have to use AI0/AI8 as a differential measure to measure temp.  My colleague is using AI1/AI9.  He is also using daq assistant in his code.  He has chosen the correct setting in daq assit..thermocouple/on board cjc..etc. 

 

My question is:

 

Can you use any  analog channel in on the scb68 to measure temp or does if have to be AI0/AI8...

 

Also, how do you select differential in DAQ Assistant??

 

Thxs..

 

 

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Unable to set maximum sample rate when using SAR NI 9223 module and Slow Sampled NI 9219 module in cDAQ-9174 chassis

May 17, 2018, 1:06 pm
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Hi,

 

I have a cDAQ-9174 4-slot chassis with a NI 9219 and NI 9223 connected.  The NI 9223 is a simultaneous SAR device capable of sampling at 1 MS/s.  The NI 9219 is a Slow Sampled device capable of 100 S/s.  The C-Series device listings are here:

http://zone.ni.com/reference/en-XX/help/370466AE-01/mxdevconsid/cseriesnames/

 

I am using a single task with a channel for a temperature measurement from the NI 9219 and a channel for a voltage measurement from the NI 9223.  The slow-sampled device is supposed to replicate data when configured at a higher sample rate if it is in a multi-slot chassis as described here:

http://digital.ni.com/public.nsf/allkb/A8257C9D58DA55E486257DD6005ECDC6

 

The data replication works fine when i specify a sample rate over 100 S/s up to 100 kS/s, but when i set the sample rate higher, a DAQmx error is generated:

error -200019

ADC conversion attempted before the prior conversion was complete.

Increase the period between ADC conversions. If you are using an external clock, check your signal for the presence of noise or glitches.

 

I have read a lot of information including this link below :

http://www.ni.com/tutorial/5376/en/

which states....

Two SAR/Slow Sampled Modules - When two SAR modules, SAR and Slow Sampled modules, or two Slow Sampled Modules are placed in the same hardware timed task, the DAQmx driver shares the same chassis or controller’s sample clock and start trigger between both modules. For the SAR and Slow Sampled Module configuration, the maximum rate that data is returned is not determined by the Slow Sampled Module. The driver will return duplicate samples for the Slow Sampled module to allow you to run the SAR module at the fastest allowable rate.

 

Thus I am trying to understand why the error is being generated.  I would like to measure my voltage input at 1 MS/s and also perform a temperature measure with the NI 9219 and simply have extra samples that are replicated for the temperature measurement.

 

Do i need to tell the NI 9219 to operate in high-speed mode?  Is there anything I can do to fix this issue?  Or is there a limitation that I am not understanding?

 

Thanks,

Gary

 

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How to automatically pad ethernet UDP packets

May 17, 2018, 2:03 pm
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I'm using LabVIEW's UDP Palette to send and receive messages over Ethernet. I noticed that when I send packets with a UDP payload of less than 18 bytes, the Ethernet packet becomes less than 60 bytes. I am using a monitor on the network (Vector's CANoe), which reports those packets as error frames because they're too short. I can easily pad the payload I'm sending, but that increases the length counter in the IPv4 header, which makes the device receiving my packets think that the padding is part of my message. Is there a way I can edit the IPv4 header length to not include the padding, or to get the LabVIEW UDP VI's to include them for me?

 

If it matters, I'm using 64bit LabVIEW 2016. Thank you for your help.

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How to increase the rate at which data is displayed on the front panel

May 17, 2018, 2:35 pm
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Good afternoon,

I am somewhat of a LabVIEW novice and I am working on a VI that my company uses to measure temperatures, pressures, and flow rates on a test stand we have in our lab. The code is attached.

 

Currently, I have the sample rate set to 100 Hz, but I would like to decrease this in order to make the data files easier to work with. However, when I do so, the rate at which the front panel refreshes also decreases. I cannot allow the front panel refresh rate to drop below 1Hz. Can anyone help me figure out what is causing the slowdown?

 

Also, it seems like the methodology I'm using to split my data and display it could be done better. I find it very difficult to navigate the rats-nest of wires on the right-hand side of the code, but it's the only way I know. Can anyone point me towards some resources to a more efficient method of displaying data?

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problem interfacing multiple usb devices with activeX and .net

May 17, 2018, 2:43 pm
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Hello,

 

I am having some difficulty interfacing multiple usb devices. 4 usb devices use activeX and 1 usb camera uses .net.

 

If I run/initialize all 5 usb devices, the camera (that uses .net) does not run properly. The camera runs properly when running by itself. I was wondering if there is some limitation with interfacing multiple usb devices with different protocols. Any help would be appreciated. Thanks!

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DAQ

May 17, 2018, 2:59 pm
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I am currently applying an Analog 1D DBL type signal to six different pressure regulators with six different AO channels using DAQ assistant. My input signal is an array of 6 DBL values. Now, I want to apply a single pulse signal to two of those channels, and be able to control that via an ON/OFF on the Front panel. The 'low' part of the pulse should be the base DBL value I was originally applying, and the 'high value' should be a value I can specify. Any suggestions on how this can be done would be appreciated. 

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Bonus (?) row in waveform chart legend

May 17, 2018, 3:18 pm
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LV2015, Win7 SP1

 

Greetings All,

 

I'm testing different instruments, and each one produces a unique set of parameters that I need to monitor.  So, the number of plots in my waveform chart & legend vary each test.  I assign custom plot names using the Plot.Name property.  I have the LegHt and LegScrollVis properties set to only display 10 rows, and the user can scroll through the entire list of plots using the scroll bar.  When I run the VI, the chart is properly displaying the data, and the legend is getting created correctly... however... when I scroll to the bottom of the legend, there is a greyed-out "bonus" row that I can't seem to get rid of.  If I click on the box identified by the arrow in the picture, that row becomes "live" and it inherits the next available label (in this case it would display Plot 22).  In addition, that "new" row is remembered the next time I run the VI.

 

In the attached pic, the instrument I am testing generates 20 parameters, and the last parameter is "Photo Valves = 000".  Plots 20 and 21 were added by clicking on the bonus row during previous runs.

 

Is this normal behavior for a custom-sized/scrolling legend, or am I somehow creating an additional blank row?  Sorry, I can't attach the code for you to review.

 

Thanks!

-H

 

 

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unattended installation systemlink client.

May 17, 2018, 4:09 pm
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Hello, 

 

I want to install systemlink client on few computers. I want to know is systemlink client unattended installation is available, so I can install it remotely on those.

 

Thanks,

Armita

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DAQmx Custom Scale Inverted Map Range?

May 17, 2018, 4:46 pm
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I am programatically configuring about 50 DAQmx voltage channels.  I am setting them all up with custom scales using the map range type.  Most of my channels have scaled units that increase with increasing pre-scaled units.  Two channels are inverted.  Is there a setting for Map Ranges custom scale to handle inverted scaling?  I could implement a table custom scale.  Just wanting to confirm I'm not missing a setting with Map Ranges before I make that change.

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Visa write skippy commands and Visa Read the return

May 17, 2018, 6:31 pm
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 Hello All,

I'm using an omega PX319-1kgi pressure transducer and Omega dp-8-pt display.

I have the display connected via the USB connection.  And the goal is to create a loop for logging the pressure data.  But for now I made test .vi to see what I'm outputting. 

 

The command is *G110 the carriage return is /r 

As far as I can tell this should read off what is on the display.

 

The Visa is opening and closing properly.  I think the problem is somewhere in the in the visa write, read, or property node between.   

 

If anyone could point me in the correct direction it would be appreciated.   I very new to labview, everything I've put together so far has been based on the reading comments and watching basic tutorials.

2018-05-17 18-21-57.jpg

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LabVIEW 2017 susiindexer.exe triggered as malware

May 17, 2018, 6:39 pm
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I was installing "LabVIEW 2017" 2 days ago in my company's laptop, halfway during installation, susiindexer.exe kept triggered and detected as malware. Is it a true valid malware or it's part of the installer package from NI?

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General Info Application Builder

May 17, 2018, 9:45 pm
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Hi All,

 

I am working through this tutorial Distributing Applications from this NI Tutorial

 http://www.ni.com/tutorial/3303/en/

My uncertainty at the moment is I am using LV2014 and when I look for the LV Run time engine which I believe should be installed on the target  Computer, there pops up a number of Run time engines ,What is the correct Run time engine and does it need to be installed on the target computer.

I appreciate your help and directions I do not need an installer I just need an executable for my test team on the vehicle  

 

Regards 

QMESAR

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NI 9207 Delta Sigma configuration, FPGA. CompactRIO Waveform Library

May 17, 2018, 9:57 pm
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Sorry to bother, but stuck in a new problem, I am using compact Rio waveform library for data acquisition using Ni 9381 (SAR module), but as I move forward I came to know I also need an NI9207 (delta sigma module) to get data from the sensor. I followed the instruction to configure my NI 9207 module for Delta-sigma FPGA file, but my module doesn't have the option to select the "data rate and to start and stop" option for data acquisition. can anybody see and help me to go through. 

The Attached zip file contains my edited project file, for (FPGA SAR acq main.vi) i have done it and it is working fiine. but for (FPGA deltaSig main.vi) i cant figure it out how to do it for my NI9207 module. any help will be appriciated. the png file contains what my probelm.

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save data to excel file

May 17, 2018, 11:58 pm
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i am trying to save data to excel file attached file shown bellow.

However I couldn't do that.

please tell me the solution.

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Adding .apk Android file to LabVIEW program

May 18, 2018, 12:42 am
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 I have an Android .apk file that I want to add to my LabVIEW program. It needs to be added exactly after the speech synthesizer is done with delivering the speech that I have inputted. I'm not quite sure how this can be done through bluetooth. Can anyone please help me on this. It would be really helpful. I'm using myRIO for this entire task. 

The name of the file in the zip folder is Face Recognition with Point Following.lvproj

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RS232 Voltage read Error 74

May 18, 2018, 12:57 am
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Helllo!

I got a problem with my code.

It works fine. But sometimes if i change the voltage i get the error 74 in String derserialize... (Memory or Data Structure is corrupted).

So i get 3 Bytes. The first byte is the start byte and the second + third are the data bytes.

 

Kind Regards,

Sascha

 

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Does OPC UA support Methods?

May 18, 2018, 1:24 am
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I learnt that OPC UA has methods, like procedure calls ("Method service set"). In a OPC UA client demo from Siemens in Visual studio (109737901_OPC_UA_Client_S7-1500_CODE_V12) I can do "Method Calling", see picture.

 

Can I call OPC UA methods also from a labview client?

 

Can a labview OPC UA server have such methods for others to call?

 

In labview 2015 I find no such vi's, but maybe it has arrived later?

 

2018-05-18 10_20_11-Start.pngOPC UA client demo in Visual studio

 

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