Channel count depends on how many independent timing signals your experiment or system requires. Single-channel units work for simple trigger-delay applications, while multi-channel models (BNC offers up to 24 channels in the 588B) are used to synchronize cameras, lasers, shutters, detectors, and other instruments simultaneously. In multi-channel systems, outputs can typically be set with independent delays, widths, and amplitude levels per channel. Opt for a rackmount unit if channel density and stackability are priorities.