Which configuration setting is NOT essential when programming an optical time domain reflectometer (OTDR)?

In the context of programming an optical time domain reflectometer (OTDR), the correct choice that is not essential is the connector type. The key settings for operating an OTDR include parameters that directly impact measurements and the OTDR's performance.

Wavelength is crucial because it determines the light signal's travel characteristics in a fiber and influences the reflectance and attenuation of the signal. Pulse width is also important, as it affects the spatial resolution of the measurements. A narrower pulse width provides higher resolution, enabling the OTDR to distinguish closely spaced events in the fiber. The noise floor is a critical setting as well; it defines the minimum level of signal that can be detected. Understanding the noise floor helps in identifying the limits of measurement accuracy and sensitivity during testing.

The connector type is not directly related to the performance characteristics of the OTDR itself. While using the right connector is necessary for ensuring a proper physical connection to the fiber under test, it does not affect the calculations or settings that define how the OTDR operates. Thus, while it’s important to have compatible connectors for practical use, it does not influence the measurements taken by the OTDR in the same fundamental way as the other settings do.