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Sending and Reading unique values of 3 Zaber T-LSR motors

February 22, 2018, 11:19 pm
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Hi

 

I have three Zaber T-LSR series motors that I want to control using LabVIEW. The three motors are connected to each other and are then connected to the computer with a single COM port. With this COM port I can select "device 0" to control all motors simultaneously or I can select device 1-3 to control them individually.

 

I want to move each motor independently, but at the same time, and while they're moving I want to read the encoder value. I have looked at all the example LabVIEW code provided by Zaber, but I cannot figure out how to do what I want to do.

 

I would really appreciate your help!

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Generate pulse greater than 50000Hz

February 23, 2018, 12:12 am
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Hello everyone, I'm new in Labview. I want to control the Delta A2 servo motor with PWM. I try many way to do, but the program broke when the frequency is over than 1000Hz. I found the counter ran fast enough. Is there any way to solve it?

 

Question：How to modify this program and let it reach 50000Hz?

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Physical channel setup while VI running.

February 23, 2018, 12:48 am
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Hi,

 

Silly question. When I choose physical channels before I start VI works fine. Once I started VI and try set up channels program doesn't read them. 

 

How can I sort it out.

It is not comfortable as I built exe file to stop running program to set channels.

 

Regards,

gregorian7

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[Robotics] DaNI Strarter Kit 2.0

February 23, 2018, 1:06 am
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Hello, I have quite big problem. I trying to use NI DaNI robot - twowheeled - I follow this manual:
http://download.ni.com/pub/devzone/epd/mobile_robotics_experiments.pdf
but when comes to  Robotics Hardwere setup in part where you should check if your sensor, servo and motors work well, it do nothind. I can change slinder on screen but nothing happend. I have connected Robot via Ethernet cable to router, set static correct IP (Don't have DHCP at school's labs), I see DaNI even in NI Max corectly. But the motors and sensor styl dont responsig in instalation. I checked voltage on every single of them and everything seems OK so I dont know, how to continue. Could you help me please? 
I using LabView 2015 have robotics module and FPGA module
And sorry if my english is bad

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Response of serial connection is messed up sometimes

February 23, 2018, 2:33 am
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Hello,

 

I have a simple serial connection (ModBus) to read out 2 kinds of data each second (see attachment "VI.jpg"). This works fine but sometimes the response Hex strings are messed up (to less bytes or to much bytes) which results in "ugly" peaks as shown in the attachment "Chart.jpg". 

 

Maybe its just a timing issue. There are a lot of LabView examples about serial connections out there and some of them has a "wait" function before R/W operations and some doesn't... Maybe you can help me to get rid of the messed responses.

 

Thanks in advance

ChriKo

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Motion controller control fails after 4 iterations

February 23, 2018, 4:11 am
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I am new to Labview and am so far strictly self taught. I am writing a program that in conjunction with another program will automatically take a user-defined set of measurements over a rectangular area.

I wrote two different codes, both of which will run fine so long as I only take 3 rows of measurement. After that, usually around the middle of the 4th or 5th row, the controller appears to not follow code.

For instance if the controller is on row 4, the first 2 measurements of that row will be taken fine. Then on measurement 3, instead of the x-axis, the y-axis might move at some increment that isn't anywhere in the program.

 

To troubleshoot, I attempted to write a third code that was as simple as possible. If I don't make the y-axis move at all, and the x-axis just moves back and forth, there is absolutely no issue, but even in the simplest code I could think of, as soon as I add in the y-axis, the code has the same failure.

 

I've attached the code for the simple version of the program, and I am using a Newport ESP-300. I'm hopeful a more experienced Labview user will have some advise.

 

Thank you,

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NI 6251 to sequentially output digital signal

February 23, 2018, 4:31 am
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I have the NI PCI-6251 card and want to sequentially produce a digital output for the two counter channels. Specifically, I want one counter to be high for 200ms, then low, wait for 10µs, then set counter two to high for 200ms, before waiting again 10µs. This cycle should repeat. Each cycle therefor takes (200+0.01+200+0.01)=400.02ms. 

In MAX, I have configured the task so that ctr0 takes the role of counter one while ctr1 takes the role of counter two. 6251 only has two counters. Unfortuanetly I am not seeing a signal on the oscilloscope...
Is my understanding of what the counters are supposed to do correct? Also, In the "Configuration" tab for the task in MAX, it says that the output terminal for both counters should be PFI13...? How are two counters supposed to run of the same terminal?

I'm not sure if I'm understanding the counters correctly.

Many thanks

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LabVIEW interface with agilent B2901A source meter

February 23, 2018, 4:37 am
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Sir,

          I am a research student, to carry out IV measurements of solar cells in laboratory i need to interface agilent B2901A source meter with LabVIEW. Since i am new to labview programming and interfacing it with hardware i need complete and detailed information right from basics. Any help would be appreciable. Thank you. 

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Code converted to Sub-vi doesn't function

February 23, 2018, 5:12 am
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Please see the attached snippet(s).

This code works fine in the loop as show.  However, if I convert it to a sub-vi (with controls and indicators exterior to the sub as usual), the code doesn't work.  I am initializing as in the attached expansion.

Can't seem to figure out why?

 

Idears?

 

Thanks all,

Chris

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Vector CANcaseXL message echo on the bus

February 23, 2018, 5:51 am
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Hello everybody,

 

first of all many thanks at TroyK for offering the great working VIs.

 

I've a question depending the CANcaseXL interface, using CAN as bus type and the CANOpen protocol.

If I send e. g. a 601 SDO-Message read with the xlCanTransmit function, I receive with the xlReceive function the 601 SDO-Message and the related 581 SDO-Answer. That works fine, but I want to receive only the 581 SDO-Answer and not the original 601 Message anymore. With the xlCanSetChannelAcceptance and the xlCanAddAcceptanceRange it's only possible to fiter the SDO-Answers.

 

Is there a way to filter the Transmit messages?

Or am I wrong in using the filter functions?

 

Thanks for your help!

Best Regards,

Jonas

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Tcp reconnect

February 23, 2018, 6:27 am
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Hi guys

 

I am using TCP Listen to connect the host pc and my RT target to transmit videostream and some more data. Then, while the RT target is still running, there are times that the host pc is being disconnected to the tcp network. When I run the host pc again, it was unable to receive the videostream and the data that comes from the RT target. I discovered that I need to restart the RT target to reconnect the host pc in the tcp network. However, this takes a lot of time. Is there any way to reconnect the host pc to the RT target again without restarting the RT target? 

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On power up MXS starts up and uses abnormal amounts of CPU and Drive resources?

February 23, 2018, 6:38 am
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On power up MXS starts up and uses abnormal amounts of CPU and Drive resources? The resources used interfere with the LabVIEW application running properly after it is loaded and executed. This problem never subsides. There are two identical systems running the same applications / version 2016 Development LabVIEW and only one windows 2010 computer exhibits this problem. The second has almost zero MXS resources being used. I have tried removing all PCI and PCIE hardware with no effect. I also tried to update the computers BIOS and load the latest LV patches. Thoughts?

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Saving entered values as default in a .exe application

February 23, 2018, 6:40 am
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I have a vi that monitors temperatures graphically using thermistors as sensors. I will be compiling this as an .exe application to use on multiple computers. I want to have a "settings tab" on the front panel that will have a number of numeric controls. The number entered into these numeric controls will be parameters of each thermistor and used to calculate the temperature. I am looking for a way to to save these values as default after they have been entered. The purpose of this is so that if a thermistor is replaced, the application can be configured with new parameters to match the thermistor.

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Network Shared Variable - Variable folder on Host PC not showing up..

February 23, 2018, 7:09 am
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Created a simple Shared variable project on two WIN10 pcs . One is a Host and the other is a client. 

 

Have followed the full instructions on this topic but surprisingly when i BROWSE for the variable from the client machine, i just get to see the Host PC but the shared variable folder is not seen. 

- RRN_HomePC is the Host PC. 

- Even tried via the NI Distributed Systems Manager

- Both PCs on same WLAN 

-Firewalls disabled on both PC  for Local Network packets

- Both PC s registered on each other ( do i have to do this once or every time i run ?) 

Have attached some snap shots to make the problem clear...can share both projects if required. 

RRN_PC.PNGBrowseSharVar.PNG

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LabVIEW random crashing after reading ACCESS database

February 23, 2018, 7:54 am
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Hello all,

 

I'm currently reading an ACCESS database (.mdb) and using database connectivity toolkit. At the moment

when I run the VI, randomly LabVIEW crashes. I have the error handler, but it doesn't give time to send error.

LabVIEW just closes up a dialog appears, mentioning that LabVIEW just crashed and if I wish to restart LabVIEW.

When I open up the VI again, the RECOVERY dialog menu appears.

 

I'm going to attach the VI, maybe my code is wrong. As I said this error comes up randomly. Sometimes it runs very

well.

 

Please some advice?!

 

Many thanks to all!,

 

José Luna.

 

 

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Scanned variable read function

February 23, 2018, 8:08 am
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My project has one cRIO 9035 and two expand 9149 chassis consists of 9235,9237,9205 and 9214 totally 192 sensors. Can anyone explain the difference between scanned variable read function and share variable node? I prefer using scanned variable read function to read all the data. What is the influence on the performance of the program? Thank you.  

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Get all text from front panel programmatically

February 23, 2018, 8:09 am
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Hey guys. I am looking for a way to programmatically get all of the visible text from the front panel of a vi. Currently I'm getting all control references and for each control getting the type and using property nodes to extract the text that is visible depending on which control type it is. It works fine, but I'm wondering if anyone has a tool out there that does this or can think of a more efficient way of doing it?

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FPGA Type Def not remembering path to bitfile

February 23, 2018, 9:46 am
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Hello all,

 

I am having an issue with a typedef for an FPGA reference.  It seems that every time I shutdown LabVIEW, the reference reverts the path to the bitfile to a previous path.  This is not a game stopper as I just point the reference to the correct path, but does anyone have any thoughts as to what is happening?  I am currently running LV 2016 on Windows 7.

 

Thanks

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variable in DCT and SQLserver

February 23, 2018, 10:30 am
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hi

 

One of my programs is checking in a SQLServer database, a recordset containing a lot of double lines to remove.

 

in order to avoid to do the parsing in my LabView code,  I began to try to remove them directly by SQLserver request. this request contains table variables. unfortunately, the recordset is returning zero values (wherehas it works in SQLserver directly OR from labview without variables)

 

I realized by creating the little code I send you joined (LV2015) that the SQL variable are simply not recognized when using the DCT.

 

is there a solution to make them useable? did I lose my time by working with something not compatible? Smiley SadSmiley Sad

 

thanks in advance for your help

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Missing data between iterations

February 23, 2018, 10:38 am
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Hello everyone,

 

I have a question for which I am not able to find a proper answer. I am using a USB-6211 through which I bring a sinusoidal signal and work with it in my computer. My code so far looks like the picture below

cap1.JPG

 

The DAG assistant has a voltage channel set to RSE terminal configuration, with 1k Samples to Read and 10k Rate (Hz). The while loop performs a number of iterations. For each iteration I get a sinusoidal waveform of 1000 samples as expected. My problem is that between two iterations the waveforms do not align properly. Below I plotted that part of the waveform which shows what happens at the transition between the 2nd and 3rd iterations.

pic2.png

 

Is there any way to fix this? I would appreciate any help.

 

KR,

Michail

 

 

 

 

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