Patent ID: 8217782
Filing Date: 2012-07-10
Classification: G05B

Abstract:
1. A field device for use in monitoring or controlling an industrial process, comprising: an internal power source; wireless communication circuitry configured to communicate wirelessly with other equipment in the industrial process and powered by the internal power source; two wire process control loop electrical connections configured to couple to a two wire process control loop; field device loop communication circuitry having a power-on input configured to communicate on the two wire process control loop when powered in response to the power-on input; and digital communications monitoring circuitry coupled to the electrical connections and configured to provide a signal to the power-on input of the field device loop communication circuitry in response to a digital signal on the two wire process control loop, whereby the field device loop communication circuitry is powered off when no digital signal on the two wire process control loop is detected and powered on with power from the internal power source when a digital signal on the two wire process control loop is detected wherein power on of the loop communication circuitry is independent of the power on of the wireless communication circuitry.