03-29-2010 09:32 PM
Hello Experts,
I am trying to read a .txt file and plot the 2 columns in the text file on 2 wavefrom charts. I am not using waveform charts because I am trying to modify an existing VI only by replacing the DAQ Assistant with ReadfromTextFile.
At present, I am able to read both channels of data from the text file and plot it. The X axis shows the sample number of the data. Instead of sample number I need the time (0-6 seconds) on the x axis. The data in the file are sampled at 800 Hz.
I have attached my present VI and sample txt file. Let me know if I need to clairfy my question.
Thank you
Solved! Go to Solution.
03-29-2010 10:13 PM - edited 03-29-2010 10:15 PM
Edit the properties of the chart so that the dT of the charts is 1/800.
You read in a 2-D waveform which has no timing information associated. Charts default to a dT of 1. By way of the chart's property dialog box, it is the setting for the X-scale called multiplier.
You'd be better off not doing all the conversion to the dynamic data type and just wire in the arrays after you've indexed them.
03-29-2010 10:34 PM
Thank you for your reply.
The multiplier solution worked.
The split signal automatically converted to dynamic data type. I used split because I wanted 2 waveform graphs, so that I can independently control the property of each graph if required.
03-29-2010 10:39 PM
Use Index Array instead. Stretch the bottom border down to get two outputs.
I'm not sure if your data is in rows or columns, so you'd need to wire a zero to either the first output's row index, or its column index. No blue express VI's needed then or split signal function.
03-29-2010 10:57 PM