Patent ID: 8358140
Filing Date: 2013-01-22
Classification: F15B,F16K,G05B,Y10T

Abstract:
1. A method for testing functionality of a field device for sending a predetermined secondary power safety control signal to a final controlling device of an industrial processing plant, the final controlling device being operated by a secondary power, comprising the steps of: providing a current/secondary power converter for generating said predetermined secondary power safety control signal to bring the final controlling device into a predetermined safe position; providing an electronic safety circuit connected in front of and to the current/secondary power converter, and which, depending on an electrical control signal received by the field device, is switched from a passive state into an active state in which the electronic safety circuit causes the current/secondary power converter to output the predetermined secondary power safety control signal; automatically adopting the active state by the safety circuit if the electrical control signal falls below or exceeds at least one of a current and a voltage threshold value specific to the safety circuit; and by use of an electronic test circuit, receiving a test control signal initiated manually or automatically when a test is desired and modifying at least one of an input current and an input voltage of the electrical control signal in a manner specific to the field device such that a test signal initiated by said test control signal and specific to the safety circuit is generated by the test circuit and transmitted to the safety circuit in order to test its functionality.