Digital delay generators are electronic test equipment that generates delays (pulses at precise, programmed intervals) to trigger devices under test. They are also for gating, timing, triggering, and syncing. Although basic digital delay generators are single-channel devices, more complex products use multiple channels. Digital delay generators are similar to pulse generators, but have a much finer timing resolution and a much lower time delay and width-jitter. Sophisticated devices which combine the functions of digital delay generators and pulse generators may provide independent amplitude polarity and level control for each output. In terms of applications, some digital delay generators produce edges to trigger devices. Others provide precise delays and width for grating.