APPARATUS FOR THE INTRINSICALLY SAFE SUPPLYING, TRIGGERING, AND/OR EVALUATION OF FIELD DEVICES IN THE EXPLOSION-PROOF REALM

摘要

The invention relates to an apparatus for the intrinsically safe supplying, triggering, and/or evaluation of field devices in the explosion-proof realm, comprising terminals at the controller end which are to be connected to a bus and to a voltage supply, terminals at the field device end which are to be connected to the field devices, and a plurality of intrinsically safe voltage supplies, each of which has different characteristic values. The apparatus of the invention is characterized in that signal defining means are provided to define different functionalities for at least one intrinsically safe pair of the terminals at the field device end.