VideoPlus+ and PDC are ways of setting a video recorder to record automatically.
PDC operates on BBC One, BBC Two, Channel 4, Five and some (but not all) ITV regions. It uses a signal sent from the transmitter just before the beginning and just after the end of the programme. The signal starts the video recorder and stops it at the end of the programme. Even if the programme starts early, is delayed or overruns, your machine will record it all.
VideoPlus+ does not use the transmitted signals, but sets the recorder to start and stop at the time the programme is scheduled to begin and end. It uses the recorder's clock to do this, so you need to make sure the clock is showing the correct time. It is best to set the machine to record past the time the programme is scheduled to end, in case it is delayed or overruns.
If your recorder has PDC and/or VideoPlus+, please see the manual for instructions. You will need to enter the programme's code number, which you can find in listings in magazines, newspapers and online.
There are several possible reasons: