Can I install IPTV in Dreambox DM520HD ?

Yes, if you install an image that is IPTV Compliant/Compatible (Like OpenPLi 4.0 IPTV, OpenPLi 5.0 IPTV),

Admin

and what is the plugins ? or what is the list ?

Most images today are capable of having in their Channel List various inputs, such as Satellite, Cable, Terrestrial as well as IPTV Links, so it's the easiest way to have in the Channel List also the IPTV Links. But you need to include the links with some tools, and you have for example EnigmaTV IPTV Generator (on Plugin Section) that is very handy for such things.

Admin

but can install on openatv 5.3 ?

I don't think that image supports it, generally the most recent images do.

We are sure that OpenPLi are for example, and generally in at very good level, but for DM520HD as there is no Japhar Image, I would probably use the OpenATV 6.0 or 6.1 for IPTV. Other images would not work.

Admin

but how can install iptv on open pli image 4.0 ?

Use EnigmaTV IPTV Generator,

http://www.ourdreambox.com/ubbthreads.php?ubb=showflat&Number=3478#Post3478

Admin

why in first image is another ip an the last image is another ?

Because it's different boxes, one you take from the channel list and one where you upload the new channel list to use the first box DVB channels as local streams to the second box.

Admin