| 摘要 |
A multiple condition sensing and multiple alarm generating monitor for an automated machine tool which is repetitively stepped through a predetermined sequence of operations comprises a sensor for sensing each of a plurality of tool operated conditions; a memory for storing, for each sensed condition and for each tool operation or predetermined block of tool operations, alarm limit data defining a set of first alarm limits; a memory addresser for sequentially accessing the memory in response to predetermined control signals used to control operation of the machine tool such that the alarm limit data accessed is changed in synchronization with operation of the machine tool; and a comparator for comparing the output of each sensor with the currently accessed corresponding alarm limit data. Further, the output of each sensor is tared by deriving, prior to taring, a reference tare value from the electrical output signal produced by the sensor; taring in an analog fashion the output signal using an analog biasing signal derived from a low resolution approximation of the reference tare value; sampling the tared signal; converting each sample to a high resolution equivalent digital signal; and subtracting from each equivalent digital signal a high resolution digital tare signal corresponding to the difference between the reference tare value and the low-resolution approximation thereof, thereby producing fully tared digital sensor output signals.
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