1. A diagnostic device for coupling to a two-wire process control loop of an industrial process control or monitoring system,
comprises:
digital communication circuitry configured to receive a digital communication signal from the two-wire process control loop,
the digital communication signal comprising a digitally modulated analog signal on the two-wire process control loop which
is modulated to a plurality of discrete analog signal levels representative of digital values; and
diagnostic circuitry configured to diagnose operation of the two-wire process control loop based upon the digitally modulated
analog signal.
|