Fig. 2-18 Selecting timebase reference source.
Here you can decide if the counter is to use an Internal or an External timebase. A third alternative is Auto. Then the
external timebase will be selected if a valid signal is present at the reference input. The EXT REF indicator at the upper
right corner of the display shows that the instrument is using an external timebase reference.
Miscellaneous
Fig. 2-19 CNT-90: The ‘Misc’ submenu.
Fig. 2-20 CNT-90XL: The ‘Misc’ submenu.
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