Patent ID: 6272445
Filing Date: 2001-08-07
Classification: G01V

Abstract:
Apparatus for logging to a storage medium input signal values as a sequence of logged values and respective time periods for which said logged values subsist, said apparatus comprising:(i) a trigger-band comparitor for comparing an input signal value with a trigger-band of signal values to determine whether said input signal value is within said trigger-band following a preceding logged value; and(ii) signal processing logic coupled to said trigger-band comparitor and responsive to said input signal value being outside of said trigger-band to trigger logging of a new logged value with a new time period and setting of a new value for said trigger-band, said signal processing logic including an inner-band comparitor for comparing said input signal value with an inner-band of signal value to determine whether said signal value is within said inner band, wherein:(iii) said signal processing logic detects from said input signal value between said preceding logged value and said new logged value one or more intermediate points having predetermined characteristics and detects that most recent point at which said input signal value was within said inner-band preceding said new logged value and logs said point as one of said intermediate points; and(iv) said signal processing logic additionally logs said intermediate points.