Automatic Transformer Test System 3300/3302 User’s Manual
7.2 Timing
Note :
The meter requires that a non-zero value be entered for “nominal value” and the
principal parameter is matched to enable the Handler outputs.
Refer to the following figure for timing guideline. Notice the START must have a duration
of lus(minimum) in each state (high and low). If START is provided by a mechanical switch
without denounce circuitry, the instrument may make many false starts.
Measurement starts at time C, which is essentially the same as time a; measurement is
completed at f. (The START signals are expanded for clarity.) Interval a-b, during which the
DUT must remain connected for data acquisition, is considerable shorter than the total
measurement time a-f. The DUT can be changed after d (“indexing on ACQ”, to save time)
or after f (“indexing on EOM”, for a simpler measurement setup), as explained below.
After the calculation interval d-e, measurement results are available for judgment and active
lines goes low. A few usec later, EOM goes low (can be used to latch holding the result
assignment). ACQ OVER, the active result lines, and EOM the stay low until the next start
command.
Set up the handler either of two ways: index on EOM or index on ACQ, as follows the
handler muse supply a signal to initiate measurement when it has completed connection of the
DUT to the test fixture.
(1). Indexing on EOM.
Set up the handler to respond to the EOM signal from the instrument, which occurs at
the ”end of measurement”, when the judgment result is available. Set up the meter to
receive its START signal from the handler’s “start measurement” signal. This setup is
simpler than one below.
(2). Indexing on ACQ.
Set up the handler to respond to the ACQ OVER signal from the instrument, which occur
when the ”data acquisition” is complete. The handler can then remove the DUT from the
test fixture and replace it with another DUT, while the meter is calculating the result. This
setup results in higher measurement rate than indexing on EOM.
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