Communication means with transducer physically spaced from interior wall of secure housing

摘要

An improved input/output channel for linking a computer control unit for an electronic postal meter to input/output units. The invention includes a converter for converting unit-output electrical signals to non-conductive carrier signals and for converting the non-conductive carrier unit-input signals back to electrical signals. Non-conducting means are used to transmit the signals between the meter and the input/output units so that any attempts to interfere with meter operation will, of necessity, involve physical evidence of tampering, observable to an inspector.