The HFS 9000 family of high-speed logic signal source instruments have a modular architecture with factory-configurable cards. The channels are digitally synthesized from a common clock resulting in highly accurate independent placement of rising and falling edges. The instruments are optimized for digital device characterization with unique triggering capabilities and a variety of pulse outputs. The product family also features low RMS jitter, the ability to compensate for external cable skews, and an easy-to-use graphical human interface.