PDC is a system that allows your video to be made to start recording at the actual time the programme begins rather than the times they put in the TV guides, this is useful when the programme starts early or late.
Basically you program you video either using videoplus codes or manually. BUT you must use the official start time. When the programme actually starts the TV station sends out a signal to start you video recording. They send the signal at the real start time and not the time listed in the TV guide.
It works very well with VideoPlus programming.
However, it is used by BBC1,2 ITV , CH4 and CH5 in analogue via your old fashioned TV aerial. Via digital sources it seems less used. I think only CH4 and CH5 use it on Sky Digital for example. (well they did when I tried it a few months back) The situation may have changed now. My old video used to display the word PDC when a channel with the feature was tuned in, so it showed me which channels do and don't have this feature.
ITV is a bit patchy, in my area (Meridian) PDC only works on programmes that Meridian make, any sourced from other ITV networks don't seem to work using PDC. I assume the PDC signal doesn't travell from one network to another for some reason.
Sky channels don't seem to use it all. I don't get OnDigital so I can't comment on that.
It seems as though PDC has died a death really now we're going digital. Apparently Tivo doesn't work with PDC right now either.
If you do use it, make sure you use the official start time or it simply won't record at all!
