RF adapter for field device with variable voltage drop
First Claim
1. A wireless adapter for use in a two-wire process control loop configured to couple to a process field device in an industrial process control system coupled to the two-wire process control loop and provide wireless communication to the process field device, comprising:
- wireless communication circuitry;
first and second loop terminals configured to couple in series with the two-wire process control loop and a process variable transmitter the first and second loop terminals carrying a loop current therebetween, the loop current powering the wireless adapter and carrying information;
a switching regulator having a switching regulator input coupled to the first loop terminal and an output;
a shunt regulator coupled to the output of the regulator configured to provide power to the wireless communication circuitry; and
a feedback circuit configured to control current flowing from the switching regulator to the shunt regulator as a function of a loop current flowing through the two-wire process control loop as measured through at least one of the first and second terminals wherein the feedback circuit is configured to control a voltage drop across the first and second terminals.
1 Assignment
0 Petitions
Accused Products
Abstract
A wireless adapter for use in a two-wire process control loop includes wireless communication circuitry and first and second terminals configured to couple in series with the two-wire process control loop. A regulator having a regulated input is coupled to the first terminal and an output. A shunt is coupled to the output of the regulator and is configured to provide power to the wireless communication circuitry. A feedback circuit is configured to control current flowing from the regulator to the shunt as a function of a loop current flowing through the two-wire process control loop.
398 Citations
21 Claims
-
1. A wireless adapter for use in a two-wire process control loop configured to couple to a process field device in an industrial process control system coupled to the two-wire process control loop and provide wireless communication to the process field device, comprising:
-
wireless communication circuitry; first and second loop terminals configured to couple in series with the two-wire process control loop and a process variable transmitter the first and second loop terminals carrying a loop current therebetween, the loop current powering the wireless adapter and carrying information; a switching regulator having a switching regulator input coupled to the first loop terminal and an output; a shunt regulator coupled to the output of the regulator configured to provide power to the wireless communication circuitry; and a feedback circuit configured to control current flowing from the switching regulator to the shunt regulator as a function of a loop current flowing through the two-wire process control loop as measured through at least one of the first and second terminals wherein the feedback circuit is configured to control a voltage drop across the first and second terminals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
-
-
15. A method of providing wireless communication to a process field device coupled to a two-wire process control loop using a wireless adapter, comprising:
-
coupling first and second loop terminals of the wireless adapter to the two-wire process control loop and in series with a process variable transmitter, the first and second loop terminals carrying a loop current therebetween, the loop current powering the wireless adapter and carrying information; generating a regulated output with a regulator in the wireless adapter coupled to the first loop terminal; providing power to wireless communication circuitry in the adapter using shunt regulator which is coupled to the regulated output of the regulator and thereby providing power to the wireless communication circuitry; communicating wirelessly using the wireless communication circuitry; and adjusting the current flowing from the regulator to the shunt regulator as a function of a loop current flowing through the two-wire process control loop as measured through at least one of the first and second terminals and thereby controlling a voltage drop across the first and second loop terminals. - View Dependent Claims (16, 17, 18, 19, 20, 21)
-
Specification