This read-only integer, ranging from -250 to 250, reports the ComPort's frequency shift in kHz from the nominal downstream frequency. A drift value creeping toward either end of that +/-250 kHz range signals aging tuner hardware or a plant problem that could eventually cause the unit to lose lock on the downstream signal entirely. For example, an engineer noticing stuRecvFreqDrift steadily approaching 250 on one STU would schedule a tuner replacement before it drifts out of range and drops offline.