Q: When the DS8500 HART modulator/demodulator is being used, the modulation operation is normal, yet the waveform coming from the equipment cannot be demodulated. The input waveform of FSK_IN observed by the oscilloscope is normal, yet the waveform cannot be seen at the D_OUT pin. Why is that?
A: The RTS pin needs to be set high while using the demodulator.