Process for the serial transmission of digital measurement values

A method of transmitting measurement values from a measuring unit to a receiver unit

• said measuring unit comprising a sensor supplying an analog measurement signal, an analog/digital converter encoding said analog measurement signal into distinct digital measurement values with a sampling rate having a selectable value, and a transmitter sending digital signals representing said digital measurement values to said receiver unit, and
• said receiver unit comprising a decoder synthesising in a real time mode recovered measurement values from said transmitted digital signals so that said recovered measurement values correspond to the digital measurement values generated by said encoder in said measuring unit,
• wherein said method comprises the following steps:
• selecting said value of said sampling rate such that the absolute value of the difference between two immediately successive digital measurement values cannot exceed a selected incremental amount,
• representing said difference and its sign by a two bit incremental alteration value as +1, -1 or 0,
• transmitting within a predeterminable period of time during which many digital measurement values are generated only one of these digital measurement values completely while of all the others only the respective incremental alteration value is transmitted, and
• within each of said predeterminable periods of time generating a first recovered measurement value by adding correctly with respect to sign to the completely transmitted measurement value the incremental alteration value representing the difference to the immediately successive digital measurement value and, thereafter, generating in said predetermined period of time all subsequent recovered measurement values by adding correctly with respect to sign the respective incremental alteration value to the immediately preceding recovered measurement value.