Patent ID: 7016741

Claim:
A signal conversion device for use in a process control system, comprising: a first pair of electrical connections configured to couple to a two-wire process control current loop which includes a two-wire process variable transmitter which provides an analog current level on the two-wire process control current loop related to a sensed process variable; a second pair of electrical connections configured to couple to an analog voltage input channel of a process device; and a first electrical component electrically connected to a first electrical connection of the first pair of electrical connections and a first electrical connection of the second pair of electrical connections, the first electrical component further configured to couple to a digital communicator to provide a connection for digital communication between the digital communicator and the two-wire process variable transmitter; a second electrical component connected between the first and a second electrical connection of the second pair of electrical connections to provide a connection for communication with the voltage input channel of the process device with an analog voltage related to the analog current level on the two-wire process control loop; and a switch connected in parallel with the first electrical component between the first electrical connector of the first pair of electrical connections and the first electrical connector of the second pair of electrical connectors, the switch configured to selectively allow digital communication by the digital communicator through the first electrical component with the two-wire process variable transmitter.