| 摘要 |
This discloses a pattern generator having a programmable product cycle timer in which a pulse train, i.e., the pattern generated, having a time raster measurable to one nanosecond can be repeated or switched from a first pulse frequency to a second pulse frequency without the usual transient switching periods between pulses. The invention accomplishes this by providing the generator with a cycle timer using a ten nanosecond clock operating in conjunction with a ten nanosecond down counter so that a pre-selected time interval, before the end of the pulse is achieved, a test is made to determine if a required condition needing a different pulse frequency exists. If such a condition does not exist the present pulse frequency is reinitiated so that at count 0 it is repeated without delay. If the required condition does exist loading of the needed pulse frequency is initiated so that upon termination of the presently existing pulse at count 0, the newly selected pulse will be introduced into the product being tested without delay. A programmable cycle timer is provided to permit the implementation of pulses which has a time raster that is other than a ten nanosecond multiple.
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