how can I generate clock in labview 8.0 and use it for programming and for hardware?

[112233]

I have to generate clock for synchronizing hardware with my program, so I need to to use this clock inside the program and as an output from A/D. The clock frequency has to be aproximately 3kHz.  

[Norbert_B]

*Insufficient information*

First of all, i suspect that you are somehow believing that software can be timed by external signals. That is normally not the case, at least if you are using a standard Desktop PC.

So please do not mix software with "data acquisition". Data acquisition can be configured to be "buffered" which means externally clocked. You can use the onboard clock for this or (in case of most hardware) any other TTL compatible "clocksource". This will ensure a clocked acquisition of the samples. The samples are then transferred to your PC and stored there as an array. So your program has to fetch the data "in time", but not "hardwaretimed".

So please share some more information about:

-What is your task

-What is the hardware you are using

-Software versions (driver, LV)

-What is your current approach

thanks,

Norbert

[Edit] There is a difference between "softwaretimed" and "hardwaretimes" acquisition. What i described in my reply would be the hardwaretimed acquisition, which i would say make the majority of all acquisitions. Softwaretimed acquisition describes a single point acquisition where a single sample is requested by the software. So each time the software requests a new sample, it will be acquired. This method heavily depends on the performance of the systems and does most often not exceed  few kHz (maybe 2 or 3). Furthermore, if you do not have a realtime or fpga, the acquisition if not deterministic which means that the samples are not acquired in a "static timeframe"; the delta t is not constant.....

Single point acquisition is only worth for very slow signals (most often up to 1kHz) or control circuits.

Message Edited by Norbert B on 12-01-2009 04:11 AM

[112233]

I have to read samples from a/d (NI USB-6211) on each clock cycle & to use this clock also as input voltage (square wave) for a led.

labview 8.0. 

[Norbert_B]

I have to confess that i am not sure if i understand your request at all. Nevertheless, i am sure that it helps if you get used to common terminology for DAQ systems. So please read this tutorial.

This tutorial is included in there and is the most important for you. 

Maybe reading these tutorials will help you to answer your question on your own.

Norbert