Patent ID: 7233745

Claim:
A field device comprising: a wireless transmitter configured to transmit data from the field device to a remote device when activated; an interface coupled to a bus, wherein the bus supplies power and control signals to the field device through the interface, the power being insufficient to sustain operation of the wireless transmitter when the wireless transmitter is activated; an energy buffer configured to store energy from the power supplied to the field device via the interface, and to supply the stored energy to the wireless transmitter while the wireless transmitter transmits data from the field device to the remote device to sustain operation of the wireless transmitter; at least one actuator and/or sensor adapted to alter and/or sense a control and/or process variable in a manufacturing field, a memory configured to store a data stream for transmission by the wireless transmitter, wherein the data stream is divided into multiple segments; and a controller configured to, for each one of the multiple segments, evaluate an amount of the stored energy available in the energy buffer prior to activating the transmitter to transmit the segment and, when the evaluation indicates that the stored energy in the energy buffer is insufficient to sustain operation of the wireless transmitter during transmission of the segment, delay activation of the wireless transmitter for transmission of the segment until the stored energy in the energy buffer is sufficient to sustain operation of the wireless transmitter during transmission of the segment.