Patent ID: 7245976
Filing Date: 2007-07-17
Classification: G05B

Abstract:
1. A positioner interfaceable with a controller and a field bus setting device to control a valve to be set to a position, comprising: a 4-20 mA communication cable from the controller located outside the positioner; an analog communications means receiving an analog signal through the 4-20 mA communication cable from the controller located outside and executing a control of the position of the valve and other predetermined functions based on a control signal received from the controller in the form of the analog signal; a diagnosis unit diagnosing abnormality of the positioner or the valve; a bidirectional digital communication cable in addition to the analog communication cable; and a bidirectional digital communication means to send a digital signal through the bidirectional digital communication cable which shows a diagnosis result of the diagnosis unit to the field bus setting device outside the positioner and to receive a digital signal containing setting information from the field bus setting device through the bidirectional digital communication cable.