How Do I accurately measure digital Polses using a compact field point

Hi All,
My Goal Is to measure the speed of an item by measuring the difference between operation of 2 switches.
Pulse can be between 100 msec and hours.
I require > 100 uSec Accuracy @ 100 msec, 1msec @ 1 Sec etc...
This architecture is fixed, What I am looking for is a method.
I am used to using M-Series NI-DAq's with their synchronus digital sampling or counter acquisition,
I have looked at a cFP-DI-304 but it looks like it is an asynchronus sample, dependent on CPU Loading.
The cFP-50x is promising but I can't find many code examples and there are a few "sorry for the missed pulse events" notes.
Does anyone have any suggestions or helpful hints for me?
Thanks in advance.
iTm - Senior Systems Engineer
uses: LABVIEW 2012 SP1 x86 on Windows 7 x64. cFP, cRIO, PXI-RT

As I said in my post, the architecture is fixed, I understand that there are many alternatives, most of them are an "Up-Sell",
Very few have extended temperature range, LV R/T, small form factor, fair price and industrial 24V operation.
We have an existing solution that uses custom hardware and I am looking to improve the accuracy, reduce size, improve reliability and reduce overall system cost,
Compact Rio is too expensive to achieve these goals.
I experimented with a cFP-DI-304 (on change method) yesterday an got reasonable results around the 1mSec mark.
I don't have a sig-gen capable of the 12V required to stimulate the inputs at a a precise rate, so I wasn't able to confirm it's accuracy.
What I want to find out is how accurate the on-change timestamps are? Do they go beyond the quoted 1kHz sampling mode? are they prone to event loss like other NI devices?, Does CPU load effect function.
How about cFP-500/502?
I would like to be able to help myself but I haven't been able to find much useful information on the inner architcture of the cFP backplane, or associated modules.
The most I could find was that the data is transferred a bit like a shared variable.and is subject to losing samples if cpu loading is too high.
In the case of event based acquisition, I am hoping that it capures the edges from a high accuracy timebase and places it in a shared variable /buffer for collection by the software.
Thanks
iTm - Senior Systems Engineer
uses: LABVIEW 2012 SP1 x86 on Windows 7 x64. cFP, cRIO, PXI-RT

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Attachments:
pulsecount.vi ‏22 KB

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