How to use "GPS -- Timestamp N Hardware Events"

[cmiranda]

Hi,

I'm using the 6608 Timing Card and don't understand much about it.  I'm trying to IRIG-B timestamp a signal that I have coming from an arb waveform gen.  But I don't know why I need to setup so many parameters in the example "GPS -- Timestamp N Hardware Events".  If someone could explain how the specifications are used and what they are used for.

I have

IRIG-B line pin 67 (PFI 30), grd = pin 33

Arb wavefm pin 2 (PFI 39), grd = pin 36 

Thanks.

--cj

[Tom_W_[DE]]

Hi CJ-

The documentation for that example viewable by enabling Context Help (ctrl+H) and hovering over the icon in the upper-right corner of the VI states that signals must be connected as follows:

---

I/O Connections:
Connect the trigger to the Gate of the selected real time clock on the PXI-6608. The default is PFI 7. Connect the GPS IRIG-B timing signal to synchronization line of the real-time clock being used. The default value is PFI 6.

---

If you use these connections then the various counter settings on the left side of the front panel should be fine at their default values.  This tutorial has a really great explanation of all of the counter parameters specified in the example in the "How to Program the PXI-6608 with GPS in LabVIEW" section.  Please take a look at this and let us know if you have any additional questions.

Other caveats of GPS use with the PXI-6608 can be found here and here.

Hopefully this helps-

[cmiranda]

Found out what the problem was.  My setup was correct, but hidden from view and made invisible is "Initial Clock Time Specification".  Turns out that the default value of "Use System Time" is incorrect and it should be set to "Use Previous Clock Time".  Once I changed that setting, presto! I got GPS time.