Abstract: A method and a highway addressable remote transducer (HART) modem for modulating and demodulating an analog signal including a HART message are provided. With low power consumption, the less computationally intensive HART modem modulates the analog signal using a coherent 8-ary phase shift keying (C8PSK) technique with a predefined gray code lookup table and a pre-generated sample lookup table having phase modulated digital signals indexed by index vectors, and transmits a HART C8PSK analog signal to sensor devices. A C8PSK demodulator in the HART modem demodulates the HART C8PSK analog signal by performing coarse estimation and fine estimation of phase errors and by estimation of a timing offset using a decision estimator. An automatic modulation classifier of the C8PSK demodulator validates presence of the analog signal in a C8PSK protocol by determining signs of in-phase and quadrature phase signals corresponding to each subsequent processed digitized sample of the analog signal.

Abstract: A method and a Highway Addressable Remote Transducer (HART) soft modem device (SMD) for transmitting a C8PSK signal and receiving and demodulating an Analog signal in either FSK or C8PSK comprising a HART message is provided. A transmitter of HART-SMD improves efficiency by reducing the computation complexity with a novel table lookup technique. A demodulator of the HART-SMD receives the Analog signal, samples and converts the Analog signal into digital data at a predetermined digital sample rate. The demodulator implements a two-step phase estimation technique followed by a single step timing estimate to achieve an optimal operating region for the receiver so that the receiver can be ready to receive state in a very short time as required in C8PSK specifications.

Abstract: A method and a highway addressable remote transducer (HART) soft modem device for modulating and demodulating analog signals with HART messages are provided. A phase coherent frequency shift keying (FSK) modulator modulates and transmits analog signals with HART messages, and a phase coherent FSK demodulator receives and demodulates the analog signals with the HART messages. The FSK modulator is a digital modulator that outputs 1 or 0 for transmission. With oversampling and low pass filtering, the digital modulation results in low jitter and good signal to noise ratio. The FSK demodulator applies a fast energy detect algorithm and dynamically reduces or increases a clock speed of a central processing unit (CPU) of the HART soft modem device for reducing power consumption of the CPU. Furthermore, the HART soft modem device uses direct memory access (DMA) to further reduce the power consumption, thereby reducing the overall power consumption by around 50%.

Abstract: A method and a highway addressable remote transducer (HART) soft modem device for modulating and demodulating one or more analog signals with HART messages are provided. A phase coherent frequency shift keying (FSK) modulator modulates and transmits the analog signals, and a phase coherent FSK demodulator receives and demodulates the analog signals. The FSK modulator outputs 1 or 0 for transmission. With oversampling and low pass filtering, digital modulation performed by the FSK modulator results in low jitter and a good signal to noise ratio. The FSK demodulator applies a fast energy detect algorithm and dynamically reduces or increases a clock speed of a central processing unit (CPU) of the HART soft modem device for reducing power consumption of the CPU. Furthermore, the HART soft modem device uses direct memory access and runs multiple instances of a HART soft modem integrated within a microcontroller to reduce an overall power consumption.

Abstract: A method and a highway addressable remote transducer (HART) soft modem device for modulating and demodulating analog signals with HART messages are provided. A phase coherent frequency shift keying (FSK) modulator modulates and transmits analog signals with HART messages, and a phase coherent FSK demodulator receives and demodulates the analog signals with the HART messages. The FSK modulator is a digital modulator that outputs 1 or 0 for transmission. With oversampling and low pass filtering, the digital modulation results in low jitter and good signal to noise ratio. The FSK demodulator applies a fast energy detect algorithm and dynamically reduces or increases a clock speed of a central processing unit (CPU) of the HART soft modem device for reducing power consumption of the CPU. Furthermore, the HART soft modem device uses direct memory access (DMA) to further reduce the power consumption, thereby reducing the overall power consumption by around 50%.

Abstract: A method and a highway addressable remote transducer (HART) soft modem device for modulating and demodulating analog signals with HART messages are provided. A phase coherent frequency shift keying (FSK) modulator modulates and transmits analog signals with HART messages, and a phase coherent FSK demodulator receives and demodulates the analog signals with the HART messages. The FSK modulator is a digital modulator that outputs 1 or 0 for transmission. With oversampling and low pass filtering, the digital modulation results in low jitter and good signal to noise ratio. The FSK demodulator applies a fast energy detect algorithm and dynamically reduces or increases a clock speed of a central processing unit (CPU) of the HART soft modem device for reducing power consumption of the CPU. Furthermore, the HART soft modem device uses direct memory access (DMA) to further reduce the power consumption, thereby reducing the overall power consumption by around 50%.