WIRELESS DISCRETE INPUT/OUTPUT WITH EXTERNAL POWER OPTION

A wireless field device for use in an industrial process includes input/output terminals to couple to a process interface element and a discrete input/output channel configured to receive a discrete input signal from the process interface element through the input/output terminals when configured as a discrete input channel, the discrete input/output channel further configured to provide a discrete output to the process interface element through the input/output terminals when configured as discrete output channel. Wireless communication circuitry transmits and receives information. A controller transmits information through the communication circuitry based upon a sensed process variable, provides a discrete output signal when the discrete input/output channel is configured as a discrete output channel and receives a discrete input signal when configured as a discrete input channel. An external power supply input is couples to an external power supply and a battery power supply input couples a battery. Power supply circuitry powers the controller from at most one of the external power supply or the battery.