esaProbeSecondaryState is a read-only SecondaryState value giving additional detail beyond the primary operational state of the ESA Probe. An administrator reads it to get the specific reason behind a probe's current operational condition, such as a dependency or resource issue, rather than just a bare up/down indication. For example, a probe reporting an operational state of disabled alongside a secondary state pointing at a dependency failure tells the technician to fix the underlying interface or reflector dependency, not the probe configuration itself.