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How can TMDS write generate error 4?

February 21, 2018, 2:21 am
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Hello all,

 

The attached piece of code generated an error 4 during execution. The first 2 VIs set several properties and the "write graph" VI write a few data channels. Then the VI generating the error is called in a FOR loop an an array of data chunks.

TDMS sample code.PNG

2018-02-12 10:31:05	Section1	ERROR: Error 4 occurred at TDMS Write in AI Raw Data Chunk.lvclass:write Samples To TDMS.vi->Section.lvclass:write Measurements To TDMS.vi:4320001->Section Monitor State Data.lvclass:write Measurements To TDMS.vi->Section Monitor State - Process Train Passing.lvclass:execute.vi:6020001->Section Monitor.lvclass:run.vi:1530002->RTmain.vi Possible reason(s): LabVIEW:  End of file encountered.

I just can't understand how it could happen. Please help me understand.

 

BTW it's coded in LV 2017 (no SP1)

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how to, in NXG, implement child window (VI FrontPanel "wizard" BACK NEXT buttons)

February 20, 2018, 11:46 pm
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how to, in NXG, implement child window (VI FrontPanel "wizard" BACK NEXT buttons) ?

they did it with subPanel container in LV2017 and earlier.

thx

Koen.

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Pump Test Loop - Data acquisition and Modbus

February 21, 2018, 3:52 am
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Hello, I am working on a labview program for measurement and control of a simple pump test loop.

 

The VFD that controls the motor is connected to a pc with an rs232-usb connection and controlled via LabVIEW using the modbus library.

Sensors that measure pressure are connected to a NI-9203 module in a NI-9174 cDAQ chassis.

 

Please see attached vi for the control system. The current program lets me control the speed of the pump and will automatically shut down the pump should the pressure in the system increase or decrease, in addition to logging the data from the sensors and motor. Due to pressure pulsations I am using an averaging filter to smooth the data from the sensors.

 

My issues are that i would like pressure sensors to sample and log data faster than the execution time of the while loop (~160 ms). At the moment im using a 200 ms wait in the while loop and a sample rate of 5 for the sensors to sync them with the time stamp and data from the motor. I'm looking for a better way of doing this.

 

Another issue is that i sometimes get Error 56 - the network operation exceeded the user-specified or system time limit, which i guess is because the communication with the vfd times out. I have a suspicion that it might be the rs232-usb converter that is causing the problem. 

 

With regards to solutions, purchasing different hardware or software is an option.

 

 

 

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how to use UMI 7764 is relied to a SMD103 drive to control a stepper motor

February 21, 2018, 3:58 am
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hi

I have a PCI 7350, relied to an UMI 7764 wich is relied to an SMD 103

my stepper motor turn all the time without any control

can anyone help me please?

 

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PID in LabVIEW

February 21, 2018, 4:10 am
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Greetings. I have one question about PID coding in LabVIEW.

 

---- "Can I use 2/3 set point in one PID vi?"

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Microsoft Windows Embedded Compact 7 - Labview

February 21, 2018, 5:01 am
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Hi there,

 

Can you confirm if labview is compatible with the OS version:

"Microsoft Windows Embedded Compact 7" ?

 

Find bellow the full details of the PC and OS:

ULTRA COMPACT CONTROL CABINET PC
Intel® Atom™ E3815, 1.46 GHz, 1 core
compact motherboard for Intel® Atom™
2 GB DDR3L RAM, expandable ex factory to 4 GB
Graphic adapter integrated inside the Intel® processor, 1 DisplayPort
on-board dual Ethernet adapter with 2 x 100/1000BASE-T connector
30 GB M.2 SSD, 3D flash, extended temperature range

Microsoft Windows Embedded Compact 7, English

 

 

Thanks a lot,

Carlos Silva

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Write to Measurement File Notification Appeared Suddenly

February 21, 2018, 6:26 am
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Hai, I am doing temperature measurement with thermocouples.  While the program was running, the program worked fine and I got the temperature of the samples and automatically save to lvm file. But, then suddenly the "Write to Measurement File" error notification appeared and it makes my program stop running. The error notification said that my lvm file was already open but I didn`t do anything. Do you know what caused it? and how to solve the problem?  Thank you

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Buscar palabras en un txt y luego mostrar la linea donde ha salido

February 21, 2018, 7:21 am
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Match Regular Expression with 2 expressions

February 21, 2018, 7:58 am
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I'm trying to create an expression that will search a string for 1 of 2 patterns using the Match Regular Expression function in LabVIEW 2016. I want to pick out 12 characters from a string of some length in a line.

 

The patterns are as follows, where 'L' is a letter (A-Z) & 'N' is a number (0-9):

  1.        NNNNLNNNNNNN
  2.        LNNLLNNNNNNN

Is it possible to create an expression to do one of two things?

  1. Search for either pattern with an OR statement
  2. Search for the first four characters with an OR statement & the last eight with an AND; ie. (NNNN | LNNL) && LNNNNNNN

Examples of valid match:

  1. 0123A9876543
  2. A12AB9876543
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Plotting two plots on graph but in different way

February 21, 2018, 7:58 am
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Hi,

1. I am trying to plot graph produced from already existing file. While running the code I want a dot to read the values in already existing plot like comet in MATLAB.

 

2. I am trying to plot an already existing plot from right side while another plot is coming from left side. The plot from right side is from already existing file and the plot from left side would be the identical points but in real time.

 

I am new to labVIEW and mainly when it comes to plotting two different graphs. I am able to plot two different graphs. But not in the fashion I have written above.

 

Thank you in advance.

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Find values from waveform, intersection point of two waveforms

February 21, 2018, 8:18 am
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Need to find intersection point of two waveforms attached in waveform only.vi

 if graph is zoomed up then the graph looks like below. During red line transition from 0 to maximum, need to find the value of P1,P2 and P3 of white waveform

Wave.png

Thanks,

 

Harish.

 

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EtherCAT Master does not show up in Labview after reinstall

February 21, 2018, 8:44 am
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Hello,

 

I recently had to reinstall Labview on my host notebook, because the SSD was formatted.

Although the PXI is recognized in the project tree, the EtherCAT-Modules (NI-9145 in this case) cannot be found.

Unbenannt.PNG

Furthermore, the FPGA inside the NI-9145, seems to be recognizable, because the FPGA-Module shows up when I try to find it on the PXI target.

Unbenannt2.PNG

 

There must be an issue with a driver or that a driver is not correctly installed. However, in the MAX, there is no compatibility issue between the host notebook and the RT target, since and all software modules are on the same version. Does anybody have an idea what the cause is? Following software is installed:

 

Labview

2017, 32-bit

NI-DAQmx

 

17.6.0

NI Device Drivers

 

2018.01

 

PXI Platform Services

 

17.5.1

NI-Motion

17.0

NI-Industrial Communications for EtherCAT

 

2.4

VeriStand

 

2017

SoftMotion Module

2017 f1

LabVIEW Real-Time Module

 

2017

LabVIEW FPGA Module

 

2017 SP1

 

Thanks alot

Lysandros

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XY graph display uncertain number lines.

February 21, 2018, 8:49 am
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Dear all,

 

I want to display uncertain number lines on a XY graph, and the number of lines is typed by the user. How to do this?

 

Thanks,

Mei

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Surface Pro 4 Core m3 tab for LabVIEW

February 21, 2018, 8:50 am
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I am planning to buy the Windows tablet shown below... the specs shown are adequate for a LabVIEW development environment.. just wanted to check if anyone has had experience of using these for LV ? 

 

Core m3 Tablet.PNG

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Custom FPGA personality & RT

February 21, 2018, 9:08 am
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Hi!

 

I am learning how to use Real-Time and FPGA module with myRIO. I'm trying to connect myRIO with a magnetic sensor (TLE5011) via SPI. The sensor requires an external clock for the PLL. I used the FPGA module to create a constant 4MHz clock on one of myRIO's DIOs. The clock only works when the customized FPGA VI is running. The problem is that the RT VI returns an error while the FPGA VI is running (−61202). 

Is it possible to run a custom FPGA VI and use RT functions (such as SPI)? Is there any other way to create a proper 4MHz clock signal?

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Data Acquisition and Processing

February 21, 2018, 9:36 am
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Hello Everyone, 

 

I am conducting a project that will collect a large amount of data, approx. 500,000 data points per sensor per file. I am recording the raw data to a measurement file while the experiment is being conducted. I am then wanting to write a program that will read the collected data from a measurement file and process the data. I am having a hard time starting this process but just for simplicity i am wanting the program to read acceleration data from a measurement file and then integrate the data to get velocity and position. After integration I would like the all data to be displayed in a time history format. 

 

Can anyone help me get started with writing this program? I have read several articles and have attempted to write the program myself with no such luck. 

 

Thank you!

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convert to nxg2 keeps telling OpenG and MGI not installed

February 20, 2018, 1:02 am
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I'm trying to convert a large project (application) from v2016 to nxg2.0, but the utility keeps telling me that OpenG and MGI are not installed although they are.

+ the preview indicated directory is not created.

 

I converted already a smaller project "succesfully", but that was a library.

 

regards,

Koen.

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Problem with 9481 giving no output - using 9485 instead?

February 21, 2018, 11:46 am
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Grad student in lab with a high temperature reaction vessel. I inherited a Labview code and cDAQ chassis with two modules from a previous student in my lab. I have a code which uses a NI 9219 to read a thermocouple, and then based upon that temperature, the code turns on heating tape through a 9481. There's an external thermocouple that makes sure the heating tape turns off once it gets too hot.

 

This has worked just fine for two years, but now the 9481 is not actually turning on my heating tape. The indicator light still turns on, but I've got no current going through. I've tested multiple heating tapes, so they're not the problem. I don't know if I have actually flipped a switch in the code or if the module is just physically broken. 

 

I have a spare module of a 9485 that was purchased as a backup, but when I plug that in in place of the 9481, nothing happens. I don't know if that needs a different boolean switch to turn on. I don't have too much coding experience, so I hope this is a trivial problem. Any advice would be greatly appreciated!

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using multiple channels with DAQmx and a USB-6009

February 21, 2018, 11:55 am
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I'm using LV 14 and a USB-6009

The example I have attached is originally posted by stmoritz back in 6/27/13, I've made a few simple changes but it is a perfect example for me to ask my question.  I should be able to group the AO and DO channels together yes?  So rather than 5 "parallel" tasks I would end up with 3 parallel tasks, 1 AO with 2 channels, 1 DO with 2 channels, and 1 AI but I am having some difficulty with the execution. How do I combine the like channels and then disassemble the data?

 

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Error -200587

February 21, 2018, 12:08 pm
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Hey,

 

I'm trying to set up a control panel for actuating a bunch of pneumatic valves. I had the program set up and working, but after plugging it into a new computer, it no longer works. I had to update the tasks in NI max, but now I'm getting error -200587. I'm very new to labview.

 

Thanks!

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