Configuring a filter and plotting two inputs against each other with a twist

[flipphil]

Thanks in advance for your help.

My first question has to to with configuring a software filter for an input voltage from a position sensor. I've attached a screenshot of the unfiltered output and the VI I was trying to configure. I got rid of a lot of things in the VI to simply focus on the filter part. I'm not quite sure what I need to do since other instructions didnt seem to be working out.

Also, I'm plotting two inputs against each other (Force vs Position) on an XY graph. I would like it to update in real time but also show continue showing the previous points of (Displacement, Force). Currently, there is only a blinking point of the current position that moves around in real time. I essentially want the graph to remember the points previously plotted on it while adding them in real time. Is this possible?

Thanks again,

Phil

[Luke_W]

Hey Phil,

            You can use the filter express vi you have there or you can use the equi-ripple low pass filter and indicate the pass and stop frequencies.

            As far as the XY graph goes, to have it plotting continuously and maintain your previous values, you will need to initialize an array large enough to contain the data points you are going to be collecting. It can be in excess, but having it initialized will save significantly more time then the other option of building an array. after you have initialized an array for X and Y (two 1D arrays of equal size) you will write the data you are collecting into the array, you can use the iteration count to be the index of write location. Then feed the two arrays into the X and Y values for the XY graph

Hope this helps,

Luke W