Emphasizing the above, if you are feeding a ferrite protected signal to a regular input you may, very well, make matters worse by using the ferrite. As a rounded signal is in the noise margin critical zone much longer than a square pulse noise can get by so much easier, if no schmitt trigger is used.

Hi Erik Thanks for that great advice I was about to step into troubles. I have already purchased 6 ferrite beads for 21 wire flat ribbon cables from RS. I am not using any schimit triggers on those boards But 74HC541 buffers are the receptors and transmitters of inter board singnals. I was planning to use these ferrites on the cables connecting boards. But from your reply it looks like the things will be better without ferrite than putting the ferrites.

Thanks & Regards,
Prahlad Purohit