The PM5654 VITS Generator and Inserter from Philips inserts digitally-generated test signals to guarantee high accuracy and stability. The PM 5654 generates VITS (Vertical Interval Test Signals) as well as full-field test signals and inserts signals for TV transmitters, satellite links, and terrestrial microwave links. PM 5654 also inserts teletext and data. In transmitters, as well as other applications, the instrument provides automatic program signal substitution.