requesting help with timing issues: lost data

[Norm]

Hi!

I'm logging data from an HP 5335a (using it as a time interval counter). and from a Motorola gps board ( text data).

The test setup is comparing the 1pps output from the gps board to a divided down 10 MHz from a Trimble Thunderbolt. The text data is used to post process the measurement from the 5335a reflecting the 1pps error (+/- 15E-9). The ver is LV 8

Code description:

Each instrument has it's own VI and I run them simultaneously, collecting data and storing it in text files. The individual vi's are for loops with the iterations being the number of seconds that I want to log. Inside the loop is obviously a delay. The data is time stamped with seconds enabled.

The problem is that somewhere in the 40k data points some (not all at the same time or sometimes one here and there) arent' collected.

Solutions that I've tried:

Using the 1pps to drive the parallel port so that I've got a hardware time hack. When I had both vi's in the same for loop things didn't go well. Not really sure what happened. Seperated them. Works well now (except for the four or five lost data points in 40k)

Varing the time constant. It's helped lots, but I really dont' want to lose any data.

Solution that I think would work:

A way of firmly triggering a start event. I've got a time server so windoze time (or lack of it!) is not an issue.

I'm not really a programmer. Actually play with trains for a living. Will be on vacation for the next week. Not much to do so I'll be able to play lots.

Thanks for your time,

Norm n3ykf