Discrete blocks seem don't work

Hi,

I've acquired a signal from a DAQ card by simulink (setting end time to inf) and i've saved it in .mat file.

Now when i apply a discrete filter block or memory block, output signal is the same.

I've tried to change solver (setting variable step solver) but result is the same. I don't understand this behaviour. Why doesn't it work ?

[Kaustubha Govind]

When you say result is the same - how do you verify that? Are you visually comparing plots of the input and output signal, or are you logging the output to the base workspace and using an ISEQUAL comparison? Also, note that the Memory block simply acts like a Unit Delay block with discrete sample times.

Regarding the Discrete Filter Block - have you design the parameters such that it actually filters any frequencies in your input signal?