US Patent 7665219 Signal transmission apparatus for a measurement probe

A measurement probe (12, 110, 250), such as a touch trigger or analogue probe, is described that comprises a deflectable stylus portion (14) and a wireless communications unit (18) for transmitting stylus deflection data to a remote probe interface (20, 104, 254). The wireless communications unit (18) is arranged to transmit digital data packets comprising stylus deflection data and a probe identity code. The wireless communications unit (18) allows said probe identity code to be set by a user. The measurement probe (12, 110, 250) may communicate with an associated probe interface (20, 104, 254) over a radio frequency (RF) spread spectrum link (106).