The Model 2601B SourceMeter® SMU instrument, part of 2600B series SourceMeter SMU Instruments family, is a new and improved one channel SMU instrument with a tightly integrated four-quadrant design that allows it to simultaneously source and measure both voltage and current to boost productivity in applications ranging from R&D to automated production test. In addition to retaining all the features of the Model 2601A, the Model 2601B has 6½-digit resolution, USB 2.0 connectivity, and software command emulation of the Model 2400 SourceMeter SMU Instrument that enables easy migration of legacy test code. The Model 2601B model is equipped with Keithley's high speed TSP® technology (over 190% faster than traditional PC-to-instrument communication techniques,) which dramatically improves the system-level speed to lower the cost of test. The TSP-Link interface enables multi-channel parallel test and expands the test system without the cost of a mainframe. The wide range of 3A DC, 10A pulse, 40 V output makes the Model 2601B suitable to test a wide range of higher current devices, materials, components, and sub-assemblies.