Sarah, thanks for your answer. Before the color problem, the main one is drawing two different signals on one graph. I don't use 3D surface.vi because of z matrix problem, I have 3 columns in txt file, x, y and z. In the example you offered me, they use only z matrix as input for 3d surface.vi. I use invoke mode for plot 3D mesh because I easily input x,y and z directly (in 3D surface.vi it reads z as 2D and do not draw exactly what I want, but invoke mode for plot 3d mesh makes it correctly.). In my multi_plot-3d_try.vi file (just for 2 signals), it draws what I want but each signal in one run. I attached my txt file and vi again, all suggestions are wellcome. Thanks again...
Orkun ERSOY
Hacettepe University