Faster photon counting and data overwritten Error -200141

[Chenyh]

I am using LabView 8.0 and 6602 card for counting the number of photon from the photon counter. There are 2 of photon detectors. (But right now, I am using 1 counter for testing vi.)
Based on the example of "Meas Dig Periods-Buffered-Continuous-High Freq Ctr.vi", it works very well.
However, when I set the measurement time less than 4ns, the data will overwritten (appear the error as following.)
Is there any possible way to make the measurement time shorter? Or it is the limit.

Thanks very much.
Chen

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Error -200141 occurred at DAQmx Read (Counter 1D U32 1Chan NSamp).vi:7

Possible reason(s):

Data was overwritten before it could be read by the system.

If Data Transfer Mechanism is Interrupts, try using DMA. Otherwise, divide the input signal before taking the measurement.

Task Name: _unnamedTask<63>

[BrowningG]

Hello Chenyh,

Thanks for contacting National Instruments.

According to page 3-13 of the PCI 6602 manual, the “minimum period required for the CtrnGate signal is determined by how fast the system can transfer data from your device to computer memory.”  

As a result, the measurement time is dependent on the computer system and will vary from computer to computer.  The value of 4 ns will be the limit for measurement time unless you switch to finite acquisition or improve the computer specifications. 

Please post back if you have any questions.