a submersible well pump has a system for monitoring the pressure and temperature in the vicinity of the motor . the system includes a downhole assembly in the well that has a transmitter for generating a signal and superimposing the signal onto the power cable . transducers in the downhole assembly sense physical parameters such as pressure and temperature and provide electrical responses corresponding to the physical parameters . the transducers are connected to a modulator which modulates the signal provided by the transmitter according to the electrical response of the transducers . the modulated carrier signal is converted at the surface into a readout signal proportional to the physical parameters .