sentences:  Modern curve tracer instrument designs tend to be modular, allowing system specifiers to configure them to match the applications for which they will be used.For example, new mainframe-based curve tracer systems, can be configured by specifying the number and power level of the Source Measure Units (SMUs) to be plugged into the slots in the back panel of the chassis.This modular design also provides the flexibility to incorporate other types of instrumentation to handle a wider range of applications.