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How can I sync my NI-PXI 5412 with an Agilent 33220A to have two same frequency signals with phase shift?

Hi everyone, 

I want to sync my 5412 Fgen by NI with another Fgen from Aglent to have two same signal (in terms of frequency ) and a phase shift, I am toatally nwe to labview, and I really need this.

I really appreciate your help.

Thanks

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Hi Riha,

 

To synchronize your NI-PXI 5412 with Agilent 33220A you will need to feed in the same start trigger signal into both devices so that they start function generation at the same time.  PFI0 and PFI1 lines on your PXI 5412 can be used for that purpose (those lines accept external start triggers). I would check with Agilent to find out if their device has a dedicated trigger line or if it can generate a start trigger that you can then feed into PXI 5412. Also to avoid signal drift I would make sure that both devices run off the same reference clock. Most of the NI PXI chassis have a 10MHz clock output at the back of the chassis which you can then use as an external clock signal in your Agilent 33220A. By the way, what PXI chassis and controller are you using? Now, when it comes to LabVIEW you can download the LabVIEW functions (VIs) for Agilent 33220A from NI Instrument Driver Network. You will also need to make sure you have NI-VISA driver installed. The latest version of NI-VISA can be downloaded from here. Finally, you can use the following LabVIEW example to generate a waveform with your PXI 5412 device, that would start off an external trigger:

 

LabVIEW >> Help >> Find Examples >> Hardware Input and Output >> Modular Instruments >> NI-FGEN >>  Arbitrary Waveform Generation >> Configuration >> Fgen Trigger.vi

 

Also, since you are new to LabVIEW and synchronization techniques here are some helpful articles that you will find useful:

 

Getting Started with NI LabVIEW Student Training

 

PXI Specification Tutorial

 

NI PXI Timing and Synchronization Design Advantages

 

 

Mikhail
RF Toolkits, Product Support Engineer
National Instruments
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Hi Mikhail,

Thank you so much for your previous response.

Actually this is what I want to do: Having two signals, with the same frequecny and controlable phase shift between them. for example two 10MHz signals, with 90 degrees shift in phase respect to eachother.

Sorry to ask multiple questions, but since I am new to this, I am a bit confused, you said, we will need to feed in the same start trigger signal into both devices so that they start function generation at the same time, but what should I use as the source of trigger here to apply to both devices? I am also confused of terms external clock, and trigger, I cant understand the differences. If I use an external trigger, why i need a clock? what is the role of the clock here?

Actually there is a sync output in Agilent, which gives a TTL output with the same frequency of the generated signal, can I use this as a trigger to apply to my 5412? Then If I can give it a desired delay in labview and then use it as a trigger I can have desired phase shift.(I dont know whether it is possible to delay the trigger befor applying it, in Labview or not?) or I can use it as a trigger without delay, to generate the same frequncy signal at the same time in my 5412 , with desired initial phase?

One of our concerns is that how much can we go high in frequncy? 10MHz?  20MHz? We really like to have synced signals up to 20MHz.

 

Our chassy is PXIe-1062Q, Our Controller is PXIe-8101 and the signal generator is PXI 5412.

Thanks Again for your time 🙂

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Hi Riha,

 

The start trigger is used to make sure both of your devices start generation at the same time. The start trigger is sent once and it triggers signal generation which runs at the clock rate. For more information on triggering, refer to the following article: Advanced Waveform Sequencing and Triggering on Arbitrary Waveform Generators. Now, you can certainly use the sync output on your Agilent device and feed it into a PFI line on 5412 to trigger signal generation on 5412. Also, you are better off using LabVIEW to adjust the start phase of your signal, then delaying your start trigger. If you are generating a standard waveform (e.g. sine, square, etc.) you can use the following LabVIEW Fgen function: "niFgen_ConfigureStandardWaveform" to adjust the start phase of your output signal. For more information on this function refer to page 2 of the NI-FGEN Instrument Driver Quick Reference. Finally, as it can be seen from NI PXI/PCI-5412 Specifications sheet the bandwidth of the PXI 5412 is 20MHz. Have a look at the following article that explains the meaning of all the specifications of your PXI 5412 card:  Signal Generator Terminology and Specifications

 

Mikhail
RF Toolkits, Product Support Engineer
National Instruments
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Hi,

Thank you so much. It seems, that it will definitely help, thanks for your precious time and help. I really appreciate it.

Ali

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@MikhailK wrote:

Hi Riha,

 I would check with Agilent to find out if their device has a dedicated trigger line or if it can generate a start trigger that you can then feed into PXI 5412. Also to avoid signal drift I would make sure that both devices run off the same reference clock. Most of the NI PXI chassis have a 10MHz clock output at the back of the chassis which you can then use as an external clock signal in your Agilent 33220A.


Hi Again,

and thanks for your help, Actually as we discussed earlier, Our 33220A has a trigger output, so I used it simply as the trigger input to PF0 in my 5412. And since I was not familiar with labview programming I just simply used  FGen Soft Front Panel. But unfortunately we have signal drift, I mean one signal is moving relative to the other signal, It seems that their frequencies are little bit different. On the other hand FGen Soft Front Panel just accepts continues trigger, with which I can't overcome this relative signal movement or drift.Is there any solution?

By the way, if I use the clock out from our chassis, and apply it to our agilent system, will this help? And since this clock is 10MHz, it means we can not go further in frequency?

Thanks Again

 

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You should sync the reference oscillators .  The 33220A has a 10MHz in  and the PXI chassis has a 10MHz out... 

Just link them with a 50Ohm cable. After that the internal frequency references are linked ..

And you should tell the NI generator to use the 10MHz backplane clock as a ref.

 

 

 

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'


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@Henrik Volkers wrote:

You should sync the reference oscillators .  The 33220A has a 10MHz in  and the PXI chassis has a 10MHz out... 

Just link them with a 50Ohm cable. After that the internal frequency references are linked ..

And you should tell the NI generator to use the 10MHz backplane clock as a ref.

 

 

 


Hi

Thanks for your comment, Actually I did this, but I have a simple problem, I have a problem that my signals are not in phase at all, for example when I am working on 1MHz, they have 90 degrees of phase shift, although I set the initial phase as zero. When I go to 5MHz this initial phase shift is 112 degrees, and this is the case for lower frequencies as well, i,e. 100KHz with 50 degrees initial phase shift, so when I want to work in each frequency I should check first for the amount of phase shift before adjusting the desired phase shift, because I don't know how much phase shift I have in each frequency. They are not in same phase at all, unless in low frequencies.

I am using sync output of Agilent, to trigger PF0 of NI-FGen, in continues trigger mode (only available option in the FGen Soft Front Panel)

and its output clock as a reference for my NI Chassis.

Thanks again (vielen dank)

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@Riha wrote:

@Henrik Volkers wrote:

You should sync the reference oscillators .  The 33220A has a 10MHz in  and the PXI chassis has a 10MHz out... 

Just link them with a 50Ohm cable. After that the internal frequency references are linked ..

And you should tell the NI generator to use the 10MHz backplane clock as a ref.

 

 

 


Hi

Thanks for your comment, Actually I did this, but I have a simple problem, I have a problem that my signals are not in phase at all, for example when I am working on 1MHz, they have 90 degrees of phase shift, although I set the initial phase as zero. When I go to 5MHz this initial phase shift is 112 degrees, and this is the case for lower frequencies as well, i,e. 100KHz with 50 degrees initial phase shift, so when I want to work in each frequency I should check first for the amount of phase shift before adjusting the desired phase shift, because I don't know how much phase shift I have in each frequency. They are not in same phase at all, unless in low frequencies.

I am using sync output of Agilent, to trigger PF0 of NI-FGen, in continues trigger mode (only available option in the FGen Soft Front Panel)

and its output clock as a reference for my NI Chassis.

Thanks again (vielen dank)


Check if it is a constant group delay (1.389µs??) (unwrap phase) 

if yes, you can compensate that ....

 

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'


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