Hello, I need to modify some bits that Labview read from a PLC using a kepserver, however the program uses an active-x library that I haven't seen and I cannot find it, I was wondering if any of you have seen it before and point me to where I can search for information.
I'm using Labview 2015
Thanks,
Javier
Hi:
I have a Labview 2013 program for testing audio in headsets.
This program works fine. It has many functions, devices, drivers, etc.
Some time ago, for some reason when I try to compile it shows error 8 (see picture) and compilation is not successful. It happens not all the time.
Then I close project and open again and it works. In some cases I need to reboot PC W7 64Bit to success compilation.
"Mass compile" function does not show any problem.
Do you have any idea what I need to do to permanently fix this problem?
How can I build a VI that read a signal .. using excel?
I am using a program called High Speed Data Logger2(DAQmx).vi, which was a program I did not design but inherited when I joined the lab. I am sampling 9 channels at 40kHz, using NI USB 6212 multifunction DAQ device. Parameters of interest in the program:
Max scans: 300,000,000
Buffer size: 1,000,000
Around data point 16777216, perfectly normal looking signal transforms to this on every channel:
I don't understand why.
So I am trying to follow this example to create TCP communications between a Python and LabVIEW. The difference is I am trying to do it on the cRIO as a real-time application that communicates via shared variables. The Python script runs without errors so I'm assuming the mistake is in my LabVIEW code, more specifically my RT.vi is where I think my problem is. The event structure probably has something wrong with it, I've messed around in a couple of different ways, but I couldn't get it to work with the shared variables. I attached the LabVIEW code for you all to take a look at.
My configuration:
- Using the cRIO IPv4 Ethernet Adapter eth0 (Primary) for the IP address
- Using the port number that is assigned to TCP/IP under "VI Server" in the cRIO properties
It's just meant to be a simple example of how to use TCP in RT on the cRIO, but I am having a ton of trouble so if someone could fix the code or do it in a better/simplified way I would really appreciate it!
Hi all,
I have a VI that opens a TCP connection with a server and talks to it. This is in "production" mode.
However, when I'm on a development PC, I don't have access to the actual server to establish a TCP connection and talk to it. But I need a "pseudo" server on my development PC that behaves exactly like the real server (i.e. has the same IP address, and can talk to my VI through a TCP connection).
I looked at the standard LabVIEW example of TCP server. It doesn't help me at all. The TCP Listener functions don't really make sense. Does anyone have any ideas to make a "pseudo" server?
Is there a more efficient way of working with digital waveforms?
I have a boolean array of 96 IO lines per transfer coming off of an FPGA FIFO, (no DAQMX)
I'd like to be able to display this data, however, the act of converting this data to a digital waveform is terribly inefficient. 1 kHz is more than my i7 can handle at this point, heres the code, the DVR is not blocking.
Hi everybody,
I'm trying to measure the phase difference between signals received by two microphones. I'm using two different USB measurement microphones that are plugged into separate USB ports. The problem I'm having is that I can't get the microphones to sync. If the microphones aren't synced up then it becomes nearly impossible to measure phase differences because the source frequency is on the order of KHz. Would it be possible to program this in Labview and sync them up or would I have to buy new hardware for this?
Things I tried:
1) I tried to make the two microphones show up as the two channels of the task ID for Sound Read Input VI so that one microphone would be "left" and the other microphone would be "right". Can't find a way for this to work.
2) I tried to just make two separate Sound Input Configure and Sound Read Input tasks but even then, one microphone will run its task and then after the other microphone will run its task until it eventually gives me Error 4823. Either way, they're not synced up.
This sensor supports MODBUS but i couldn't find enough information on it's datasheet to implement it.
Hello
I need your help to solve this project
I just have one hour and I don"t know how to start and what to do
I need your step to follow 
I use Labview 17.1 and usb-6003 DAQ for my design. After random amount of time from the beginning of the program changing between 2 seconds to 56 seconds, firstly Labview freezes and then it throws the following error.
A USB transfer failed due to a transaction error reported by the USB host controller. This may be due to a fault in the system's USB host controller, a USB cable, or a USB device.
I know that this error was already discussed in white pages and forums but I could not solve it. I tried suggested solutions: I tried different cables, disconnected and reconnected it, disabled and enabled the device from device manager, I tried both usb 3.0 and and 2.0 drivers (by the way if you can tell me which one is better for usb-6003 I appreciate) and I prevented Windows to close serial ports to save power but still I have this problem. I found a way on internet to reset the decive whenever device is disconnected, but I prefer a real solution rather than a walkaround. What else can I do to solve this problem?
I have function written in dll (c++) as:
unsigned long myFunction( myStruct data );
struct myStruct
{
uint32_t parameter1
uint32_t parameter2
};
My quiestion is: Is it ok to call myFunction like this in Labview:
uint32_t myFunction( uint64_t data);
Hi again,
I deleted the visa aliases for the cmodules in MAX and they die not come back after complete new Labview install. But I need them to access all the ports on my cmodules.
Rearranging them on the cRIO does not bring them back, delete and update view in MAX does not work. Edit visaconf.ini does not work.
Any other ideas?
cRIO 9074, NI 9870 and 9871
Hi all,
I am LabWindows/CVI developer from past 2-3 years. Now i need to work on Labview to create test automation tools.
To make it Labview programming easy, can i compare or relate LabWindows i.e. Functions and variables etc. available in LabWindows. with LabView programming. It helps me to learn LabView quickly as i am already know LabWindows.
Only thing i can easily compare is Labview is graphical programming language.
Regards,
Anand
Hello.
I am working on a project for my degree with LabView and LabView FPGA. I have a problem with a timer and how to count when there are pulses coming. I am measuring steps from a stepper motor which are generated as very short rising and falling edges or in other words pulses. I now need to make a timer when the steps are moving (motor runs), signal should be true, the timer counts up and when the steps are in hibernation (motor stands), signal should be false, the timer stops and if i run the motor again it continues the timer and so on. I have made a simple code and it works with a toggle switch but when i try to implement those steps onto the trigger, it doesnt work. Am i even doing the step trigger correctly?
Thank you
Hi'
I am running LabVIEW 2017 and Multisim 14.1
I have followed two different tutorials regarding how LabVIEW and Multisim can work together. However, I cannot find the Multisim functions in my LabVIEW block diagram.
The Multisim icon is missing from “Control & Simulation” > “Simulation” > “External Models”. It is also missing from “Connectivity”. However, I have been able to prepare a file (.ms14) with LabVIEW-terminals, so Multisim seems to work just fine.
I assume that I am missing some LabVIEW plugin, but I do not know which one. Anyone?
Thanks in advance
Mathias
Hello,
The documentation page http://zone.ni.com/reference/en-XX/help/371361P-01/lvconcepts/how_labview_stores_data_in_memory/ write to variant only: LabVIEW stores variants as handles to a LabVIEW internal data structure. Variant data is made up of 4 bytes.
I have binary data from an array of waveform, flattend as string and have to read it outside of Labview (C#, C++) . With the refered documentation I can read: ArrayDimension, t0, dt, data array.
But than come the attributes as variant.
Where can I find the documentation of the variant memory layout?
Peter
Hello everyone,
I am learning a Labview and have a question. I am reading a data from the file, then compare it with a random number that I generate. And if two numbers are equal, I would like to increment my variable.
I was able to do it with a shift register, but I have to wait until my for loop finishes then I can see my value.
Is there any other ways to increment a variable ? Because, in later, I would like to terminate the for loop if my variable exceeds certain value for example 3.
Here is my VI screenshot.
Hi,
I have BK9117 power supply.
I am trying to communicate with the power supply using RS485.
I can able to control the power supply using GPIB.
When I use RS485 , using NI MAX on the VISA test panel When i send the command *IDN?\n and read it back I get following error
Read Operation
Error
VISA: (Hex 0xBFFF003E) Could not perform operation because of I/O error.
I am using the USB-RS485-WE from FTDI.
I connected the Yellow (DATA-) to pin 1 of the BK9117 RS485 which is B-
I connected the Orange(DATA+) to pin 5 of the BK9117 RS485 which is A+
The configuration setting of the serial port in the BK9117 power supply and NI VISA Test Panel is same and I have verified it. The settings are as follows
Baud rate - 9600
Data Bit - 8
Stop Bit - 1
Parity - none
Looking at the view attribute section of the NI VISA Test Panel I found Is Port Connected is invalid property value.
Searing for VI_ATTR_ASRL_CONNECTED in google I found the following
https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z0000019L7PSAU
So if i need to communicate with my device is that I need to use the USB-485 developed by NI and not any third party devices ?
