Monitoring terms-DC line lock

DC line locking is an ancient technology that uses DC 50/60 Hz power line current to synchronize the camera. Because the DC 24V power supply is widely used in most building fire alarm systems, it is very easy to obtain. Since the old models of switchers and split systems do not have a digital memory function, to maintain a stable image, synchronization between cameras is very necessary. DC line lock means that the cameras are synchronized to AC 50/60 Hz, and the time correlation and level between color channels / The vertical signal is not constrained and will result in poor color conversion (color phase design), so all users who use the AC line lock will inevitably lose good color conversion. Fortunately, current splitters and 16-channel composite processors and hard disk video recorders have internal memory to overcome this problem. Synchronization signals are no longer needed, so the AC line lock may be eliminated in a few years.