Patent ID: 8878685
Filing Date: 2014-11-04
Classification: F15B,F16K

Abstract:
1. A field device comprising: a calculation processing portion that operates by receiving a power supply that is sent through a first transmission path; a communication processing portion that operates by receiving a power supply that is sent through a second transmission path; an isolating circuit that is provided between the calculation processing portion and the communication processing portion, wherein a burnout signal that is produced by the calculation processing portion is outputted to the second transmission path by the communication processing portion through the isolating circuit; an inverting circuit that inverts a signal that is branch-inputted through an output line from the isolating circuit; a selecting circuit that receives a signal from the output line of the isolating circuit as a first input and the inverted signal from the inverting circuit as a second input, and that selects either the first input or the second input in accordance with a selection setting status, to output, to the communication processing portion, the selected signal; and a selection setting status transmitter that transmits the selection setting status in the selecting circuit to the calculation processing portion, wherein: the isolating circuit maintains a voltage level of the output line at a predetermined voltage level that indicates a predefined burnout signal when the power supply to the calculation processing portion is turned OFF when the power supply to the communication processing portion is tuned ON; and the calculation processing portion further comprises: