Smart transmitters can normalize gain and offset, linearize the sensor by converting its analog signal to digital, process the signals with arithmetic algorithms resident in the microcontroller, convert back to analog, and transmit the result as a standard current along the loop. They also add the capability for digital communications, which share the twisted-pair line with the 4-20 mA signal. The resulting communication channel allows for transmission control and diagnostic signals along with the sensor data. The SoC that integrates AFE, microcontroller, HART®, and 4-20 mA transmitter technology allows for the small size of the 4-20 mA smart transmitter.