| 摘要 |
An apparatus for calibrating a timer of the type having a first and a second input channel in which an initial signal arriving over one input channel initiates a timing cycle, while a subsequent signal arriving over the other input channel terminates the timing cycle, the initial and subsequent signals being transported to remote ends of the first and second input channels from remote sources by means of first and second signal conductors. The apparatus comprises a commoning conductor, a test signal source, and first and second signal routing networks, the first signal routing network being capable of selectively coupling the first signal cable, the test signal source, one end of the commoning cable, and the first timer input channel, while the second signal routing network is capable of selectively coupling the second signal cable, the test signal source, or another end of the commoning cable and the second timer input channel. The differences in delay times associated with different signal paths are determined by a series of tests using the test signal source to generate signals to start and stop the timer, while the signal routing network configure the apparatus in selected testing arrangements.
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