Patent ID: 8595519

Claim:
A bus instrument ( 10 ) configured to predictively limit power consumption and adapted for use with a two-wire instrumentation bus, the bus instrument ( 10 ) comprising; a sensor ( 13 ); a shunt regulator ( 14 ) configured for shunting excess electrical current; and a controller ( 20 ) coupled to the shunt regulator ( 14 ) and the sensor ( 13 ), with the controller ( 20 ) being configured to generate a predicted available power P predicted that will be available to the bus instrument ( 10 ) after a change in the loop current I L , compare the predicted available power P predicted to a present time power P t0 comprising a controller power P controller plus a sensor power P sensor , and reduce the sensor power P sensor if the predicted available power P predicted is less than the controller power P controller plus the sensor power P sensor .