Clock disciplining 1.1 on RT PXI target

[poklad]

Hi All!

I have Labview 2012SP1 and PXI-1036DC (S2 switched to "external clock") with 8101RT+6653 (Slot2) + 6682 (Slot3)+4462+6143

I try custom "Labview RT Waveform Acquisition and Logging sample project" for my tasks.

I need PXI_Clk10 disciplining and add to target disciplining software. I want to test disciplining and deploy Clock Disciplining App. And do not see nothing. The questions are:

1. My previously steps was correct?

2. May this occurs due to bad GPS antenna position? In MAX I see 2-3 satelites and self survey do not complete.

Jury

[BenRobinson]

Hi poklad,

The driver used to disciplne the PXI_Clk10 comes within a separate library that I have linked here.

NI-Sync 3.3.5 - PharLap, Windows 7/Vista/XP (SP3) 32-bit/Server 2008/Server 2003

Once you have installed that driver, you will download and unzip this package of VIs. Choose the correct slots of your chassis and run the VIs for several minutes. It is best to follow all of the instructions included in the manual on this page.

Let me know if the above driver and documentation are clear enough.

[poklad]

Hi!

I already make all procedures, as described in the manual (see fig4).

Up to this stage the documentation is clear enough.

But after that - Multi-device PXI_Clk10 Disciplining 1.1 is the "Black Box".

I run Clock Disciplining App on PXI target and... see fig3 in my first post. After 1 hour nothing occurs.

Also I want to clear the next questions this situation is real, but not described:

1. After PXI power ON 6682 self survey can not complete due to bad GPS antenna position. Will the 6653 generate PXI_CLK10 autonomously?

2. The 6682 GPS lost signal during disciplining process. Will 6653 continue drive PXI_CLK10 in accordance with its own accuracy?

Jury

[BenRobinson]

Hi Jury,

If the 6682 cannot obtain a good GPS signal it will not trigger the other timing module to discipline the PXI_Clk10. Make sure that you are placing the chassis in a location that allows it to connect to 3 satellites and maintain a good signal with them. That is why you are seeing the application not running, because the 6653 is never  triggered by the 6682 to discipline.

It is my understaning that if the 6682 were to lose connection, the 6653 would continue on disciplining the chassis clock with its onboard clock.

[poklad]

Hi!

Thank you for answer!

Because the Multi-device PXI_Clk10 Disciplining 1.1 is a "black box", what is better way to realize the next algorithm:

1. After chassis power ON the 6653 became generate PXI_CLK10 "as is", i.e. with its own accuracy. Is it possible do it in MAX?

2. If the 6682 self-survey process ended and the GPS locked, the Multi-device PXI_Clk10 Disciplining starts disciplining PXI_CLK10 clock.

Jury

[BenRobinson]

Jury,

You can export the clock on the 6653 to the backplane in the test panels of the 6653. Go to the Routing tab. Add a new route. Choose the source as the oscillator and the Destination as PXI_Clk10. Keep in mind that the Test Panel will reserve the device and not allow for other operations like trigger routing.

To avoid hanging on the GPS card, you could include code to check for a good signal. If it is not present you could go forward with using the 6653 onboard oscillator.