Abstract: An electronic postal meter, adapted to be driven by a meter base has a shutter for controlling the application of drive input to the meter, and a solenoid driven interposer for blocking operation of the shutter until conditions for printing postage are met. The solenoid is energized by way of a pair of serially connected transistors, which are in turn controlled by separate micro-processing systems. The separate micro-processing systems continually exchange messages concerning the operational status of the postal meter, whereby each of the controlling systems is responsive to conditions under which the postal meter should not be operative, to thereby control its respective transistor.