The instrumentation at the FCRAO is under the control of the ModComp Computer and various microprocessors distributed throughout the facility. A user can modify and configure remote instrumentation by issuing commands to the tracking programs. In this chapter, we summarize the tracking program commands that are used to control the various instruments at the observatory, including the antenna, subreflector, receivers, spectrometers, and the radome environment. It is important to note that the commands discussed in this chapter only include control of those aspects of the instrumentation that are under software control and do not consider the full operation of the instruments. For more complete descriptions of the latter, observers are referred to the observer's guides that are generally available for each instrument.