LabView

[nonmm]

hi,

let say i got this equation.

Kc=1;
Ti=1;
Td=1;
L=1;
w=0.01:0.01:1.01;
PID = Kc*(1+ 1./(j*w*Ti) + j*w*Td/((j*w*Td/10)+ 1));
block1 = angle(exp(-j*w*L).*(j*w+1).^(-6) .* PID) + pi;
plot(w,block1);

how do i plot in labview as i got no problem in matlab?

Thanks in advance.

[smercurio_fc]

Don't hijack someone else's thread.

Create a new thread with your quesion.

[stanthetiger]

Hi sine help,

When you convert from dynamic data to an array of scalar, you will lose all the timestamps in the data. You would need to calculate your dt based on the sampling rate (1/Sampling Rate) you set in Simulate Singal VI and build a waveform with the proper timestamps added to it.  I've modified your VI to illustrate what I have said.

Regards,
Stanley Hu
National Instruments
Applications Engineering
http://www.ni.com/support

[sine_help]

Thanks for your Help in hilbert. Can you please tell how i can recover symbol timing of qpsk signal using lab view what type of tools i need in Labview. or Plaese send a toturial, papers through which i can understand the process. please Dont send any thing which uses alot of math to explain. i am B.E student and need help in final year project. I want Practical implementation in Labview.

[stanthetiger]

Hi sine help,

If you're acquiring the signal as a waveform than it should contain a timestamp. Please refer to Wavefrom VIs and Functions in LabVIEW 8.5 help for more information on how to manipulate waveforms in LabVIEW.

Regards,
Stanley Hu
National Instruments
Applications Engineering
http://www.ni.com/support

[sine_help]

I have Labview 8.5 . problem is i want to open and run VIs built in Labview 5.0.1.. how can i run . i have checked that they run perfectly on labview 6. what type of files i need

[Dennis_Knutson]

LabVIEW 8.5 cannot open VIs older than version 6 so all you have to do is open your 5.0.1 VIs with your version 6 and save them.

[sine_help]

I am using NI 5661 spectrum analyzer.and RFSA .i want  to record  FM radio channel eg 100MHz.. in example i found some VIs which requires following parameter for I & Q data

center frequency

I&Q rate ( S/s)

samples per record

Q1.

i want to know that  can we configure digitizer sampling rate ie 100MS/s to 20,10,50MS/s etc. and secondly is   I & Q data rate  are data coming out of on board signal process by digital down conversion. please correct my concept ie. Digitizer is always sampling at 100MS/s . but through spec given to I&Q data rate ie. eg 1MS/s  it digital down convert 100MS/s data rate to our spceified data rate ie 1MS/s. and it contain same information as 100MS/s data contains.

 Q2.

once i have record  I&Q data to disk using write measurment file VI. i want to play back .should i use arbitray wave generator to regenerate data because file size is 900MB and it contain data at different time i want to listen songs again. how can i do that after recordind file name

fm100.LVM format.

Q3

in eample VI  it requires central frequeny. please also correct my concept here again.

let suppose i give central frequeny 100MHz. downconveter  tunes it self at 100MHZ and downconverts 100MHz signal to IF 15MHz and feed it to digitizer input where digitizer samples it at 100MS/s and and output data rate from digitizer in form of I&Q we specify eg 1MS/s. so we get FM 100 transmision at rate of 1MS/s which we can record for play back.

can i record whole spectrum ie 88MHz to 108MHz after that i can select my desire station to play back if possible please tell me how  or i must have to give a particular frequeny .

PLEASE CLEAR MY CONCEPT SO THAT I CAN BETTER USE THIS DEVICE. AND ALSO HELP ME HOW CAN SOLVE THIS PROBLEM.

[sine_help]

is there any vi or algo through wich i can find center frequency of a signal in labview. 

[GovBob]

Are you still referring to data collected from the PXI 5661? If you are you could try to use the Configure Acquistion Type.vi set to spectrum. Wire that to the Configure center span.vi , the Configure resolution bandwidth.vi. Wire that into the Read Power Spectrum (cluster). vi and output that into the SMT Spectrum Peak Search.vi. You will also need to use the Get Spectral Info for SMT. vi as this will set up the input parameters for the Peak Search.vi.

Note: You might want to post questions about the 5661 on the RF Measurment Devices forum as it is more focused towards using/programming these devices.

Hope this helps.