How to fix delay in data saving for an Encoder and 7 AI signals having same Time ?

[tajim]

Dear All!

I am using a PCI-6221 M series device with SCC-68 connector board. With this setup I am acquiring data from an encoder and seven AI channels and trying to save it in a same file having a same time column by using a Write to Measurement File VI. The read VI and Writ to Measurement file VI are placed inside a while loop. The problem that I am facing is a delay in Data Acquisition and also wrong storage of the data in different columns of this Write to Measurement File VI. What I meant is when I start saving the file, the acquisition program slows down and it does not write all the data correctly. Also, the program works fine when I am just saving AI data with time column using same Write to Measurement File VI and the saved file shows well placed data with corresponding time history of the data acquisition. The problem starts when I include Encoder data in the same file. The program gets slower and slower with missing and misplaced time and data values! What I figured out that instead of having a time history the Encoder data is just having number of samples which are set in the program (for example 1000 or 1024) in its time column. The Encoder is a Quadrature (A, B and Z channels) with 1024 pulses per revolution. Is it possible to have a same time history of the Encoder as I am getting for AI channels? I hope that some one can help me to resolve this problem! Attached is the program for your review!! Thanking you all in advance!

Regards!

Tajim