5644R Synchronization RF Sweep Error

[Zarrar]

Hi Guys,

              I am trying to implement RF sweep on synchronization VI with 5644R but when I change frequnecies on Run Time Error comes which Is attached below. I have attached VI also. Please let me know I can add RUN TIME RF changing on both CWS which are synchronized. If these is solution suggested please let me know. 

[Captain_K]

Hi Zarrar,

I’m little confused at when this error is occurring. Are you trying to update the output frequency while the VI is running? With the code that’s posted, the frequency is only ever set at the beginning of the program.

For the error, can you run your code with highlight execution on and report back which property node is giving the error? I’m assuming RFSG Upconverter Center Frequency in the False case, but I’d like to be sure.

Do you know where 1.299000E+9 value is coming from? From the front panel, it’s looks like you’re setting the frequency to be 1.2G. The 5644R has a bandwidth on 80MHz, so I’m trying to determine where this value is coming from that pushing us out.

[Zarrar]

I am trying to change frequency on Run Time like with syncronization I want to change the frequencies from 1G to 6GHz. But when I change frequencies on run time error comes. Please let me knwo whatr changes should I do in order to implement run time RF change. 1.299 I have inserted this values and I.2 is initial frequency set while it started execution. I want to know how should i implement run time sweep witrhout error.

[Captain_K]

I'm still a little confused on how you're getting this error with the code that was posted. In the code, the frequency is only set at the beginning of the program and can't be updated. I also compared the Front Panel from the code to the screen shot and these look different. Can you post an updated version of your code.

For updating the frequency on the fly, are the frequencies going to be preset or user controller?

In either case, I'd recommend looking at the shipping example RFSG Frequency Sweep.vi. This example shows how to use the Ramp Pattern VI to sweep through a set number of frequencies. This VI can also be modified to take is user inputs. This example if located in the following location:

C:\Program Files (x86)\National Instruments\LabVIEW 2015\examples\instr\niRFSG

[Zarrar]

I am trying to generate two CWS with 75ps delay. After this I have to change frequencies at Run Time like 1Ghz to 6GHz with steps of 1MHZ. I have seen example which you are refering to me. But that example is for One CW. I have to implement it on two CWS with synchronization.I  am using the 5644r shipping example which you can see in post but when I change run time RF. eRROR comes.Can you please suggest how I can chage RF an run time without getting error and stop the VI.

One thing more, If i have to generate pulsed CW like for 10ms it should be off and for 10ms it should be on, how it would be imnplemented?

[shawn.t]

Zarrar, please share the code that you're using currently to sweep frequency---the code that is giving you the error. The example that you posted above does not have any way to sweep frequency so we're not sure how you're trying to do it. We need to see your code to understand where the error is coming from.

To do a pulsed CW tone, you'll want to use arbitrary waveform mode. Create a waveform that has 10 ms (number of samples = IQ rate * 10 ms) of 0.0 values for I and Q followed by 10 ms of 1.0 values for I and 0.0 values for Q. Play this waveform with infinite repeats. See the arbitrary waveform generation example.

[Zarrar]

I am using the above updated code for RF sweep. I want to modify it in order to put sweep from 1GHz to 6Ghz with 1000. steps on bothe VSTS. Caa you guide how to achieve RF Sweep on both VST which are syncronized. I aslo want to generate triggers on PFI0 output of 5644R. I am unable to access 5644R pfi0 using instrument design libraries. I want to generate pulse on 5644R

[Captain_K]

You’re going to have to make changes to the code you originally posted to be able to sweep. Have you tried implementing anything that you’ve seen from either the RF Sweep example or Arbitrary Waveform Generation example?

If yes, what have you tried and what are the results?

If no, please go ahead and try. You’re going to have to combine multiple examples to achieve what you’d like to do.

[Zarrar]

Here I have attached a VI ,which is made after doing changing in 5644R syncronization VI and RF frequency list configuration VI. Currently, one RF is getting sweep but other is not negative sweeping like it going down. One power level is fine but other is low.I have to generate CWS on Same power but differnet RF. Please see this VI and let me know where should I do changes.

[Captain_K]

I don’t currently have access to two 5644R’s, so I can’t test your code. Are you wanting one sweep to go up in frequency and one to go down in frequency? If so, you’ll have to great a different ramp pattern for each.

For the power level, what are you expecting the values to be and what are they actually? And how are you measuring these?