초록 ▼

Conversion circuitry for use in a process control system is adapted for coupling to a primary process control loop. Digital receiver circuitry in the conversion circuitry receives a digital signal transmitted over the primary process control loop from a field transmitter and responsively provides a

Conversion circuitry for use in a process control system is adapted for coupling to a primary process control loop. Digital receiver circuitry in the conversion circuitry receives a digital signal transmitted over the primary process control loop from a field transmitter and responsively provides a digital output. A microprocessor receives the digital output and responsively provides a secondary loop control output. Secondary loop control circuitry for coupling to a secondary process control loop receives the secondary loop control output from the microprocessor and responsively controls current flowing through the secondary process control loop. The current flowing through the secondary process control loop is related to the digital signal transmitted by the field transmitter.

대표청구항 ▼

Conversion circuitry for coupling to a field transmitter over a primary process control loop, comprising: digital receiver circuitry coupling to the primary loop for receiving a digital process variable signal from the field transmitter sent over the primary process control loop and providing a digi

Conversion circuitry for coupling to a field transmitter over a primary process control loop, comprising: digital receiver circuitry coupling to the primary loop for receiving a digital process variable signal from the field transmitter sent over the primary process control loop and providing a digital output; control circuitry receiving the digital output and responsively providing a secondary loop control output; and secondary loop control circuitry for coupling to a secondary process control loop including a current source for controlling current flowing through the secondary loop in response to the secondary loop control output whereby an analog current in the secondary loop is related to the digital process variable signal provided by the field transmitter.