Patent ID: 7593642

Claim:
A field device comprising: at least one actuator and/or sensor configured to alter and/or sense a control and/or process variable in a manufacturing field; a wireless transmitter and/or receiver configured for wireless data communication between the field device and a remote device when activated; an interface configured to receive operating power and to provide energy to the wireless transmitter and/or receiver during wireless data communication; an energy buffer configured to store energy from the operating power and to supply the stored energy to the wireless transmitter and/or receiver during wireless data communication concurrently with the energy provided by the interface; and a controller configured to evaluate the stored energy available in the energy buffer prior to activation of the wireless transmitter and/or receiver and delay activation of the wireless transmitter and/or receiver when the evaluation indicates that the stored energy in the energy buffer plus the energy provided by the interface is insufficient to sustain operation of the wireless transmitter and/or receiver during wireless data communication.