An electrical test instrument comprising a base unit having a first communication address. A remote display unit separate from the base unit and having a second communication address is also provided. Communication circuitry is operative to provide electrical communication in a first RF mode between the base unit and the remote display unit as a bound communication pair based on the first and second communication addresses. The communication circuitry is further operative to operate selectively in a second secure communication mode. The first and second communication addresses are exchanged in the second secure communication mode to establish the bound communication pair for subsequent communication in the first RF mode. In some exemplary embodiments, the second communication mode is an optical communication mode (e.g., an IR communication mode).