The MCRF202 is a passive Radio Frequency Identification (RFID) device that provides an RF interface for reading the contents of a user memory array. This device is specially designed to detect the logic state of an external sensor, and alters its data transmissions, based on the condition of the sensor input. The device outputs a normal bit data stream if the sensor input has a logic `1' state, but outputs an inverted data stream for a logic `0' state. In this way, the reader can monitor the state (condition) of the external sensor input by detecting whether the data from the device is a normal or inverted data stream.