Problems with data aquisition and digital input

[Guandalug]

I am using matlab to record Analog input. Now we have additional digital signals that reflect external changes in the experiment. The signals are very short (1 ms) and thus easily missed.

My Application is set up to check back every 1 ms and read the digital line, but it seems the matlab code isn't fast enough (Matlab 6.1 with Data Aquisition toolbox). Now my question is: Is there anything like a 'buffer' on the NI PCI-6013 (D6F28B) where I can get the last msec of digital data or something like a trigger that informs me whenever the signal changes?

Or maybe is there another trick to get matlab to read the digital line constantly? Right now I'm using the card's timer to generate events every 1 ms to read the dig
ital input lines (even though the system's way too slow obviously).

I'm grateful for any help
Andre Meiske

[Sarah Thompson]

Guandalug,
This first thing you should do is contact The MathWorks for support. They are in the best position to give you the most up-to-date support.

That said, the Data Acquisition Toolbox is limited in its functionality. As stated in its User Manual, it can not perform buffered digital I/O. Have you tried testing your application in the Test Panels of the Measurement & Automation Explorer? If you can see your signal correctly in that utility, then it is definitely a DAQ Toolbox/MATLAB software issue. If not, then check your signal source. The data lines need a TTL signal to read data correctly.

Hope this helps.