Access of free running counter (from Timer Card) by Analogue Input Card

[Kai42]

Hello,

(how) is it possible, to directly have a analogue input card access the timer card, when both are installed in the same PXI rack?

I am using a PXI 1033 Data acquisition rack with

-a PXI 6602 ( 6608) Timer / Counter card (for precise recording of the time of signal edges)

-PXI 4472 Analogue Input cards for measuring analogue voltages.

The devices are accessed directly by script (C, C++), not by some NI GUI software.

Currently, the measured data from the analogue inputs is transfered to a computer; also, the value of the counter when the timer card registers an edge in the signal line.  Hence, I have no precise timing information about the measured data from the analogue inputs. The goal is to have the same time base for the analogue inputs AND the signal edges, so the counter value when each integration time slot starts (or ends) is needed.

Therefore, I would like to know, how the analogue input card can be programmed to directly read the counter value (of the PXI660x timer card) and that this value is then also transfered to the computer along with the measured analogue values. This would be the preferred method, since this method allows continuous data recording.

A possible alternative would be to have the timer card send a trigger at certain, predefined time intervals and the analogue input card start a single measurement upon receiving this trigger pulse.

Thank you for any advice,

Kai42

[bavci]

Hi Kai42,

If you not using LabVIEW, which is actually the best option, then you can have a look at the text based NI-DAQmx examples. You can search for "counter" examples on the following link:

Text Based NI-DAQmx Data Acquisition Examples

http://www.ni.com/example/6999/en/

Once you gain some traction with your text-based program, you can share your code here on Discussion Forum so that people can help you solve specific issues along the project.

Good luck,

Bart