Data Translation DT9800 Series, User Manual

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Chapter 2
54
Figure 7 shows an example of an event counting operation using a
logic-high gate type.
Figure 7: Example of Event Counting
Frequency Measurement
Use frequency measurement mode to measure the frequency of the
signal from counter’s associated clock input source over a specified
duration. In this mode, use an external C/T clock source; refer to
page 47 for more information on the external C/T clock source.
One way to perform a frequency measurement is to use the same
wiring as an event counting application that does not use an external
gate signal. Refer to the
DT9800 Series Getting Started Manual for
wiring examples.
Gate Input
Signal
high level
enables operation
low level
disables operation
External C/T
Clock
Input Signal
event counting
operation starts
event counting
operation stops
3 events are counted while
the operation is enabled