The Common Interface can be used for pay-to-view TV ; a module is used to interface between the pay-to-view card and the TV or device. This allows manufacturers to install a single (common) interface into their devices rather than many. It is a similar concept to USB
Hope this helps?
Regards James
------------- In the beginning there was darkness.
Then I bought a tent.
I'm not destitute, I'm just poor.
I still have a "Top Up TV" (Media Guard) CAM module for terrestrial UK TV, although it is more of a museum piece in these days.
Of course the original plan was that the CAM module goes into the CAM slot on the TV, and a viewing card would be inserted into the CAM module.
CAM modules were more widely used in satellite set top box's, and there used to be a big market in satellite CAM modules and viewing cards.
In fact it went down in history that Sky got away with only having one Sky CAM module manufactured, that was kept in Ruperts safe, as at the time all satellite pay TV providers had to produce CAM modules for there encryption platform, so that there services could be viewed on any make brand of satellite set top box.
Of course Sky being control freaks, we're having none of it.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.