From: tsunami on
I posted this message on the MULTIFUNCTION DAQ forum this past weekend but did not get much response so I thought maybe I should try this forum as well.  I am VERY PUZZLED & would be exhuberant for anyone's insight.  I even opened a service request with NI but the AE apparently has no answer as well to date.
 

I am attempting to read in a quadrature encoder signal, process the data & resend the processed info back out of the USB-6229 DAQ board.  I keep encountering either error 201025 or error 200802 depending if I set the autostart option of the DAQ write to T or F.  As an experiment I successfully constructed a simple DAQ read & write loop that reads in a square wave from a signal generator.  The simple VI works GREAT but when I apply the same strategy to my VI reading an encoder signal I cannot avoid the 2 error messages with the dialog below.  I AM LOST.  ANY SUGGESTIONS?  I have attached a pdf that shows my VI's + I included both VI's.  The 1st VI in the PDF is the one that works well & the 2nd is the problem child. 
 



Error -200802 occurred at DAQmx Write (Analog Wfm 1Chan NSamp).vi:6

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Possible reason(s):

&nbsp;

Measurements: Write cannot be performed when the task is not started, the auto start input to DAQmx Write is false, the Sample Timing Type is something other than On Demand, and the output buffer size is zero.

&nbsp;

Call DAQmx Start before DAQmx Write, set auto start to true, modify the Sample Timing Type, or change the output buffer size.

&nbsp;

Error -201025 occurred at DAQmx Write (Analog Wfm 1Chan NSamp).vi:6

&nbsp;

Measurements: Non-buffered hardware-timed operations are not supported for this device and Channel Type.

&nbsp;

Set the Buffer Size to greater than 0, do not configure Sample Clock timing, or set Sample Timing Type to On Demand.

&nbsp;

&nbsp;


PID outputb1.vi:
http://forums.ni.com/attachments/ni/170/344958/1/PID outputb1.vi


READ WRITE tasks1.pdf:
http://forums.ni.com/attachments/ni/170/344958/2/READ WRITE tasks1.pdf


Read2write1.vi:
http://forums.ni.com/attachments/ni/170/344958/3/Read2write1.vi
From: RT4CY on
This is a duplicate post. Please refer to this <a href="http://forums.ni.com/ni/board/message?board.id=250&amp;message.id=41952" target="_blank">link</a> for further information.
In order to maintain the forums in an orderly manner and to keep problem solutions and information in a consolidated fashion easily searchable by customers, duplicate posts are often linked. Best of luck in future applications.