I know what ext. 752 is, what my question is, is there any way for this ird to accept a HU instead of the p4? I have a hu test card I would like to use but I'm getting 752 card not compatable. I ran into this before with the h and hu and a simple change of the cam id and zkt and the ird thought it had an hu in it but really had a h? Any info or help? Please, I have been waiting on these new systems for 10 months. Thanks