Digital delay generator outputs are typically logic level, but some offer higher voltages to cope with electromagnetic interference environments.
Historically, digital delay generators were single channel devices with delay-only (see DOT reference below).
A third channel can then be used to trigger and gate a data acquisition or imaging system a distinct time after the laser fires.
(see reference on high-speed photography below) Digital delay generators are usually the heart of the timing for larger systems and experiments.
Digital delay generator manufacturers have added remote programming schemes that facilitate the creation of such GUIs.
The field of PIV, particle image velocimetry, encompasses several subsets which would use digital delay generators as the main component of its timing where multiple lasers may be triggered.
Another useful setup is to have one channel drive flash lamps a preset number of times, followed by a single Q-switch, followed by a delay and gate for the data acquisition or imaging system.
[1] A new development is digital delay generators that have gating and external triggering, dual or multi-trigger capabilities.
The multi-trigger versions have programmable logic controller-type functionality for incorporating interlocks, latches, dynamic delay adjustment, and trigger noise suppression.
Gating allows regions of interest to be processed and stored while ignoring the bulk of unwanted data.
A vital issue in the design of DDGs is to generate triggered delays having crystal-oscillator precision but that are not quantized to the edges of the reference oscillator.