Measure Power using Labview and two PXI-4071 DMMs

Hello,
I am trying to make a simple VI. I am measuring input AC voltage and Current using two PXI-4071 DMMs. I want to Calculate Power and Power Factor. I am able to read the voltage and current fine. I just dont know how to calculate the power and power factor. Im looking for real power not watt*amps. Please Help.
Scott
Attached is my VI
Attachments:
Measure AC Voltage and Current.vi ‏42 KB

Scott,
It appears that another applications engineer (Sean_N) has been assigned your initial forum post. I assure you that he is working on finding an answer to your question. We would like for our customers to limit questions to one forum so that we do not duplicate efforts on our end. I will contact Sean to remind him that you are awaiting a response. I will also point all future traffic from this post to your initial one.
Thanks,
Kareem W.
National Instruments
Web Product Manager

Similar Messages

I am trying to use Labview and RP1210 compliant hardware to connect to a truck J1939 bus and receive messages.

I am trying to use Labview and RP1210 compliant hardware to connect to a truck J1939 bus and receive messages.
Specifically I am attempting to read data frames using the RP1210_READMESSAGE . am able to configure the hardware and send a message to the J1939 bus. . I think I have not configured something correctly. I can use the RP1210_SENDMESSAGE and see the message I have sent on the bus using CANalyzer When I use the RP1210_READMESSAGE I get the timestamp from a message and the return from the function sends back the correct number of bytes (the number matches the number of bytes I sent out plus four bytes from the timestamp). What I am having trouble with is actually receiving the data. I have had the same type of behavior from two different hardware (Vector CANcase XL and Nexiq USB Link), so I don't think the issue is vendor specific.
Has anyone been able to make the RP1210_RECIEVEMESSAGE function work correctly?
Thanks for any help

Thanks
I have already tried that. The links are the NI RP1210 wraper. The problem I am having is using labview to interface with the RP1210 layer. The RecieveMessage char*fpchAPIMessage this is the output which is a pointer to a cahracter array. In this variable I can receive the timestamp of the message but not the message. The retun showns the correct amount of bytes are aviaable (18 for a 8 byte message) but I can only get the 4 byte timestamp I think I have to dereference this pointer to view the data. I am not sure how to fix this.

Please help me with my electrical engineering homework : temperature control and watering system for greenhouse using labview and arduino

temperature control and watering system for greenhouse using labview and arduino
spesification :
1. max temp : 28 celcius (when temperature is more than 28 celcius, fan ON)
2. min temp : 20 celcius (when temperature is under 20 celcius, heater ON)
3. watering system : aquaponic (grow plant and fish in separate tank but connect each other). Plant roots help filter water for fish. Fish poop for plants fertilizer. So I need a pump to distribute water.
Please help me create VI file simulation.. I'm sorry I'm not fluent in English. May God bless you all
Attachments:
YOOOSHH.vi ‏88 KB

Duplicate thread. Please keep the discussion in that thread where you already have a response. It is also the more appropriate thread for your question.
Lynn

How to recognize certain word or voice (like cry) using labview and kinect?

By using labview and kinect, how to recognize some sample world like 'ok', 'help', and voice like crying and screaming?

This is not really a LabVIEW question, but a signal processing question. Do you have a set of crying sounds in order to be able to calibrate whatever algorthm you are trying to implement?
LabVIEW Champion . Do more with less code and in less time .

Strain measurements using labview and DL750 scopecorder

Hi
I want to use labview to do strain measurements using DL750 Yokogawa Scopecorder. I have installed the DL750 drivers and I can access them from labview, but I am a bit lost as to getting to communicate with the scopecorder, setting up measurements and so on. I am all new to strain measurements and to labview, is there a link or a tutorial that anyone would recommend I refer to?
Regards, tickle

Hi Tickle
It looks like the driver you are using is supported by a third party. I took a look at the driver you are using and it has a couple of examples included with it. I would recommend taking a look at these examples as they are normally a good starting point for communicating with your device. Has anyone else used this device in LabVIEW?
Best Regards,
Adam G
National Instruments
Applications Engineer

Measuring power using NI-USRP and Spectral measurements tool kit

Hello every one
I'm just inquiring how to calculate the power in a channel using NI USRP and SMT tool kit because I have failed calculating it using direct method so I purchased SMT so could any one help me by providing me with an example that describes how to calculate the power using spectral measurements tool kit , our he could tell me the steps that I could follow .
Thanks a lot

Hi MHantera,
I don't think I'm fully understanding your most recent message. The FFT Spectrum (Mag-Phase) VI in the USRP example as well as the FFT Power Spectrum and PSD VI both output a full spectrum that already includes the f0 and df so you don't need to set those. If you're using the later you should select Power Spectrum (the default for "export mode") for the In Band measurement. Using that VI are you seeing a size limitation? What settings and sample size are you trying to use? Is it returning an error about being unable to perform the FFT or are you just not seeing the results you should? Any more information you can provide about this would be helpful.
Best Regards,
Peter W.

Measure power/current being delivered by PXI-4110 on a specific channel?

I have a PXI-1033 chassi and inside it there's a PXI-4110. How do I use LabVIEW 8.2.1 to determine the power/current consumption on a specific output channel?

I have a PXI-1033 chassi and inside it there's a PXI-4110. How do I use LabVIEW 8.2.1 to determine the power/current consumption on a specific output channel?

How to detect a lost TCPIP SOCKET using LabVIEW and NI VISA

I am using VISA functions in LabVIEW to remotely communicate with instruments over TCPIP SOCKET visa resources. In general this all works well by simply creating a resource name, passing it to VISA Open and then setting a couple of session attributes. Occasionally an instrument will be reset or power cycled and what I have noticed is that I need to call a VISA Close and then reopen the resource in order to get it to communicate again or close LabVIEW and run again. If you just use VISA Open without calling a VISA Close first you cannot communicate with the target. The problem is that I have no way of detecting this condition. I have tried always calling a VISA Close before VISA Open and this seems to work for this condition but it seems odd to always close a session before opening it. Why does VISA OPEN not work under this condition and is there any way to detect this situation?
Solved!
Go to Solution.

It works that way because that is how TCP works. A TCP connection is a dedicated connection between two endpoints. Unfortunately other than getting an error from a read or write operation there is no way to determine if the othe rside of teh connection is still there. You need to close the connection because otherwise VISA will continue to use th eold connection which is no longer valid. Closing it allows the system to cleanup the dead connection.
If you are communicating fairly infrequently you could simply open the connection, do you stuff and close it. The overhead for establishing the new connection is not that much. If you are using steady streams of data then you will need to watch for the errors and then reestablish the connection by closing the old one and opening a new connection as you have observed.
Mark Yedinak
"Does anyone know where the love of God goes when the waves turn the minutes to hours?"
Wreck of the Edmund Fitzgerald - Gordon Lightfoot

Real Time ADC/DAC for SMPS using Labview and USB

Hello all,
I have asked the sales department this same question, so here's a two-pronged approach:
I am reserching a control algorithm for a switch-mode power supply, and so far, the simulations for its performance look good. Now, the goal is to implement the circuit for experimental data.
I've seen several NI USB DAQ boxes that appear to have the performance I'm looking for (for example, the USB-6211 would have the resolution and sampling rate that I need).
The control algorithm uses the following math functions: add/sub/mult/div/exponent, and derivative/integral.
My question is this: is Labview "strong" enough to take in four channels of 250Ksps data, crunch the numbers in an equation, and spit out the answer to an analog out channel, all in REAL time? I'm looking for an analog output rate of ~100kHz.
Thank you for any suggestions that you have!
-Rick
Solved!
Go to Solution.

Hey,
So if you were just trying to perform an input or output then the USB-6211 would certainly be able to handle it because the hardware clock would be handling the input/output, not software. However, what you're wanting to do, basically a feedback system, will require software timing (at least for a USB device) because you'll have to be able to actively specify what the output is. So, for that reason alone, and the fact that you want 100kHz output, this device and USB devices in general won't be an option no matter what software you use, LabVIEW or otherwise. On another note, what you're looking to do sounds more like live updating, not Real-Time, which is more about jitter. Bottom line, for these kinds of requirements, you're going to need to move to an FPGA board, something like the NI PCIe-7841R would work. It's more expensive, but for your requirements, FPGA is going to be the only option and it comes down to bus latency as well as software response time. With FPGA, as is shown in the first diagram of the following document, you're basically closing your software loop through hardware.
FPGA Fundamentals
http://www.ni.com/white-paper/6983/en
--Ryan S.

How do I establish serial communication using LabView to two stepper motors using a motor controller?

I currently use an off the shelf motor controller to run my two stepper motors. It already has integrated a firmware software that sends commands to operate each motor. I would like to create an interface where I can send these commands using LabView. If someone can point me in the right direction I would appreciate it.

Look at the examples for the serial VISA vi. Something like Basic serial write and read.vi is a good starting point.
Have you searched for a LabVIEW driver at the NI LV driver network? Asked the vendor?
If you write your own driver with the serial VISA vis remember to open and configure the port only once at the beginning and close it at the end of your program.
Message Edited by Henrik Volkers on 07-13-2009 04:21 PM
Greetings from Germany
Henrik
LV since v3.1
“ground” is a convenient fantasy
'˙˙˙˙uıɐƃɐ lɐıp puɐ °06 ǝuoɥd ɹnoʎ uɹnʇ ǝsɐǝld 'ʎɹɐuıƃɐɯı sı pǝlɐıp ǝʌɐɥ noʎ ɹǝqɯnu ǝɥʇ'

Using LabView and Modbus to Communicate with AKD Servo Drive

I’m working on a project to control a Kollmorgen AKD servo application using Modbus directly from LabVIEW. I’m new to both LabVIEW and servo drives so forgive me if this seems simple. I have established communications to the drive through Modbus and have been successful at some rudimentary control of the servo. I know the drive only supports "Write Multiple Registers” and “Read Holding Registers” functions and there are scaling factors that need to be applied. What I need is some help with taking the Modbus information supplied by Kollmorgen for each command and formatting it for communication to the servo and vice versa. I need to understand how to take the supplied 8, 16, 32, and 64 bit information for commands, scale it, and format it into the two or four registers required for the drive to read the parameters. In turn, I also need to understand how to take the same information and read it and scale it from the drive. I’ve attached a spreadsheet with the particular commands I’m interested in and a sample VI that seems to work for speed control but to be honest, I'm not sure how/why.
Attachments:
KM Modbus Cross Reference.xlsx ‏57 KB
VEL.CMDU.vi ‏10 KB

OK, I've got the ability to read values from the AKD drive pretty well sorted out. I'm now having trouble with the ability to write. I want to use Labview to program Motion Tasks in the AKD drive. To do this I need to perform three commands: MT.NUM (specify the motion number), MT.P (specify the angular position), and MT.SET to set the parameters for the task. MT.P requires sending a 64 bit signed float or a 32 bit signed float (requiring four or two registers respectively). I used ModPoll to see what values the drive held in the MT.P registers after entering the desired angular position using the AKD Workbench software. For example: using Workbench I entered 234.567 for the angular position and read 208 and -32506 from registers 2060 & 2061 (the 32 bit registers for MT.P). After scouring the forum I put together the attached VI to try to write to the same registers but I can not seem to get the translation of the input (angular position) to the register values correct (entering 234.567 does not produce 208 and -32506 in registers 2060 & 2061). Anyone have any ideas?
Attachments:
Motion Task Definition Rev H.vi ‏21 KB

Looking for full time position using Labview and/or PLC's in Long Island NY area

I have 13 years experience using Labview for user interface/daq applications. I also have 20 years experience with Programmable Logic Controllers (PLC) programming for industrial machine controls. My resume follows:
Adam Wechsler
111 Holbrook Rd.,Holbrook,NY 11741,(631) 981-1013 [email protected]
Objective
Labview programming, virtual instrumentation, industrial machine controls,
automation, PLC, HMI, GUI, data acquisition
Education:
B.S. Mechanical Engineering 5/89
Polytechnic University, Brooklyn, NY
A.S. Engineering Science 5/86
Suffolk Community College, Selden, NY
(GPA 4.0 Dean's List Spring 1986)
Experience:
Controls Engineer 5/1994-3/2009
Vacuum Instrument Corp., Ronkonkoma, NY
*Program, troubleshoot, and upgrade automated Vacuum Chamber Industrial Leak Detection systems controlled by Allen Bradley PLCs in an OEM environment.
*Debug equipment functions and programs prior to shipping, at customer's site, and by phone.
*Integrate and install various types of peripheral equipment, barcode scanners and printers,
*Design and develop Labview graphical user interfaces and HMI applications including recipe management and data collection for industrial machinery.
*Write and review user manuals and installation instructions.
Production Engineer 10/1989-5/1994
Izumi Corporation, Yaphank, NY
*Program, maintain, troubleshoot, and repair PLC controlled hydraulic, pneumatic, and control systems for automation in a hands-on environment.
*Improve design for manufacturability of new products and prototypes to be urethane/injection molded.
*Program, maintain, troubleshoot, and repair six axis hydraulic paint spraying robots.
*Create interface between multiple PLC’s and central computer system.
*Improved design and productivity of high volume, computer controlled, robotic molding machine by 150%.
Consulting Projects:
*Created Labview user interface components, and recipe management system for the testing of motion control servos.
*Programmed Allen Bradley PLC machine logic for packaging machine for a food service supplier.
*Created Labview to Allen Bradley PLC setpoint and monitoring interface for electric motor-starter test stand.
*Programmed Allen Bradley PLC and PanelView operator interface terminal for cosmetic packaging assembly machine.
*Developed Labview application for Fourier and statistical analysis of myogram biomedical data for researching the efficacy of acupuncture treatment.
Other:
*Attended National Instruments Labview training courses, and regularly attend local Labview Users Group meetings as a long standing member.
*Member IEEE
*13 years experience with Labview
*15 years experience with vacuum chamber, mass spectrometer, and related technologies
*20 years experience with PLC's and automated systems
*Attended Autocad training course.
*Willing to travel

Will also consider contract, part time, or consultant work.

How to detect baby crying using labview and webcam?

Hi, I am new to labVIEW. I have a project that it requires me to develope a application to detect various types of baby crying using labVIEW.The hardware we use will be webcam or kinect xbox 360. The system for my computer is windows 7. I used to try to create a threshold frequency to detect baby crying,but it not work well. So I want to ask what else method should I use to develop this application that can differentiate baby crying with other kind of sound( like normal talk, music...) correctly? As I just start learning labVIEW, hope the method to be easy to understand. Thanks.

This is not really a LabVIEW question, but a signal processing question. Do you have a set of crying sounds in order to be able to calibrate whatever algorthm you are trying to implement?
LabVIEW Champion . Do more with less code and in less time .

Plot different data set depending of some conditions using labview and veristand

Hi Community,
i have a couple of points saved as XY data points on my desktop. The files are save as csv. the idea is to read the file utilizing the Read From Spreadsheet File vi when some conditions are met and then plot the XY data wiht XY Graph Addon of the veristand workspace.
for instance:
if case 1 is true read the corresponding file and then plot the first set of data
if case 2 is true read the corresponding file and then plot the second set of data
if case n is true read the corresponding file and then plot the n set of data.
Could you give some advices how to implement it (Labview and Veristand)?
I'm using LV and NIVS 2012
Thx
Mich
Attachments:
vide.vi ‏35 KB

Hi Michel,
I believe the easiest method will be to use the VeriStand .NET API to call into VeriStand and utilize LabVIEW for creating the decision making cases that you have. I have attached some examples of using the VeriStand API in LabVIEW.
Using the NI VeriStand .NET API in LabVIEW to Control a VeriStand System
https://decibel.ni.com/content/docs/DOC-32268
Where Can I Find LabVIEW Examples Using the NI VeriStand API?
http://digital.ni.com/public.nsf/allkb/E1066949FA67B6CE862578A7005988D5?OpenDocument
Please let me know if this helps.
Matt S.
Industrial Communications Product Support Engineer
National Instruments

How do you track a moving object using Labview and Vision Assistant

I am using Vision and Labview to create a program that tracks and follow a moving object using a high end camera. Basically what it does is it detects a foreign object and locks on to it and follows it where ever it goes in a control sized room.
I have no idea how to do this. Please help. Or is there an available example.
Thanks.

Hello,
It sounds like you want to look into a Vision technique called Pattern Matching. Using our Vision tools, you can look for a image, called a template, within another image. Vision will scan over the entire image of interest trying to see if there are any matches with the template. It will return the number of matches and their coordinates within the image of interest. You would take a picture of the object and use it as the template to search for. Then, take a picture of the entire room and use pattern matching to determine at what coordinates that template is found in the picture. Doing this multiple times, you can track the movement of the object as it moves throughout the room. If you have a motion system that will have to move the camera for you, it will complicate matters very much, but would still be possible to do. You would have to have a feedback loop that, depending on where the object is located, adjusts the angle of the camera appropriately.
There are a number of different examples a that perform pattern matching. There are three available in the example finder. In LabVIEW, navigate to "Help » Find Examples". On the "Browse" tab, browse according to "Directory Structure". Navigate to "Vision » 2. Functions". There are examples for "Pattern Matching", "Color Pattern Matching", and "Geometric Matching". There are also dozens of pattern matching documents and example programs on our website. From the homepage at www.ni.com, you can search in the top-right corner the entire site for the keywords, "pattern matching".
If you have Vision Assistant, you can use this to set up the pattern matching sequence. When it is complete and customized to your liking, you can convert that into LabVIEW code by navigating to "Tools » Create LabVIEW VI..." This is probably the easiest way to customize any type of vision application in general.
I hope this helps you get started. Take care and good luck!
Regards,Aaron B.
Applications Engineering
National Instruments

Measure Power using Labview and two PXI-4071 DMMs

Similar Messages

Maybe you are looking for