Hello I am having a frustrating problem with my code that involves the use of DAQmx_Start and DAQmx_Read vi's. My problem seems to involve the way I input the "timout" and "number of samples" for DAQmx_Read. In my code I have a while loop and a True/False Case structure that actives when I press "Scan". The while loops is always activated until I stop it. There is a Stacked Squence within this Case Structure. One of the first sequences has the DAQmx_Start vi which should begin the data acquisition of my scans (I am recording 4 analogue voltage values from 4 physical channels). The rest of the sequences carry out the scanning procedure that involves motorized stages and other changes but nothing with DAQmx vi's. Outside of this Stacked Sequence but still within the True/Falce Case structure is the DAQmx_Read vi. Here is my problem because even though the motorized stages are moving and the other commands are being executed once the True/False Case Structure is activated, the DAQmx vi's don't seem to record the voltage values. DAQmx_Read is set up as Analog 1D Wfm NChan NSamp. Sometimes by playing with the timeout and number of samples per ch for this vi, I actually do get some data recorded. However, I have not found a consistent techquine for always recording data because the number of samples per ch that I need are constantly changing per scan. Please see attached a picture of DAQmx_Read vi and also my code itself. From what I understand I either am almost always calculating the timout/number of samples per ch improperly or the DAQmx_Read vi should be placed elsewhere... perhaps outside the True/False Case Structure? I have not tried this. Someone please advise. Also, how should the "number of samples per ch" for DAQmx_Timing vi that I use at the very beginning of the DAQmx set up differ from DAQmx Read vi? I understand that my code is very involved and might benefit from Event Structures but, believe me, I have tried and failed. Thank you!Alfredo Message Edited by AlfredoT on 02-20-2010 06:33 PM

LabVIEW

What do you need our team of experts to assist you with?

How can we help?

Please enter your information below and we'll be intouch soon.

This field is required

Preferred communication method

Email Phone call

What do you need our team of experts to assist you with?