Abstract: Apparatus and methods for determining a linear position of a moveable member having a code disposed thereupon. The code includes a succession of data fields having at least n characters and including a frame-synch symbol at predetermined intervals in the code. A sensor reads the code on a predetermined portion of the moveable member. The predetermined portion of the member includes code having at least one frame-synch symbol and n characters. The sensor transmits a data signal as a function of the read code. A processing device is coupled with the sensor to receive the data signal. The processing device transmits a position signal as a function of the data signal, with the position signal being indicative of the linear position of the moveable member.