Hi,
I am using LV 8.5 and PCI 6229 card for real time control of a structure.
The VI I am attaching has controller whose transfer
function I am putting from the front panel. Control is for a SISO
system, so I am taking one AI from the PCI 6229 card and I want to get the output
from the AO of the 6229 card, which I will give to my actuator for
closed loop control of my structure. The Transfer function should take input as the AI and provide output as the AO.
The difficulty I am facing is this:
I am using a discrete
transfer function block (Firstly please tell if this is the correct
block to be used in my case). I observe that for whatever input,
the output is not as desired: The TF just functions as a gain instead
of as a 'phase change + gain' block. Eg: If I put the transfer function
as ' 2*z / (z+10) ', I get the ouput as input multiplied by 2. If I put the TF as ' z^2 / (z^2 + 20z + 6128), then I get the output same as the input for the input being at any frequency (0 Hz to 200 Hz). The
effect of phase change is not occuring.
Please tell where I might be wrong. Also give some examples which might help me in going ahead.
Thanks,
Mandar
