Atec Agilent-8753E - Manual (Page 15)

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HP 8753E supplemental characteristics, cont’d
Offset value
Set the offset frequency value.
Service menu
Select the desired service test, service diagnostic,
service or verification mode.
Test sequences
Description
Create, edit, save or recall a series of front-panel key-
strokes to automate a measurement. Each of the six
sequence registers can hold approximately 200 instruc-
tions. Create or edit a sequence by selecting the sequence
menu and then simply performing the front-panel key-
strokes that would normally be used to make a manual
measurement. Test sequences may contain basic stimulus
and measurement functions (frequency, power, parameter,
format, scale) advanced operations (time domain, limit
testing, display marker values) and basic logical branching
(IF limit test fails DO sequence 5). Completed sequences
are then saved and can be executed when you are ready
to repeat the test.
Storage
Test sequences can be stored internally to a disk drive and
can be loaded from a computer over the HP-IB interface.
Sequence 6 is saved in nonvolatile storage and can be used
as an autostart routine when titled AUTO.
Branching
Branch to another sequence on limit test pass/fail, or the
loop counter value. Subroutines are also possible via
GOSUB.
Other HP-IB instruments
Send simple commands to HP-IB instruments via the title
string.
Test sequence BNC output
Set TTL high or low on the rear panel output.
General purpose input/output
Read or write bits to the output port to control external
devices such as part handlers. Eight output and five input
TTL lines are available on the parallel port of
the HP 8753E.
Other functions
PAUSE/continue, wait, title sequence, print sequence,
duplicate sequence, pause and select. Time Domain
(Option 010)
Time domain (Option 010)
Description
With the time domain option, data from transmission
or reflection measurements in the frequency domain is
converted to the time domain using a Fourier transforma-
tion technique (Chirp Z) and presented on the display.
The time domain response shows the measured parameter
value versus time. Markers may also be displayed in elec-
trical length (or physical length if the relative propagation
velocity is entered).
Time stimulus modes
• Standard stimulus
Two types of time excitation stimulus waveforms can
be simulated during the transformation — a step and
an impulse.
• External stimulus
The definition of other time excitation stimulus wave-
forms can be accomplished using an external controller.
• Low pass step
This stimulus, similar to a traditional time domain reflec-
tometer (TDR) stimulus waveform, is used to measure low
pass devices. The frequency domain data should extend
from DC (extrapolated value) to a higher value, the upper
limit being defined by the test set used. The time domain
response shows the parameter value versus time (multiply
by the speed of light, c, to obtain electrical length or by c
and Vrel to obtain physical length). The step response is
typically used for reflection measurements only.
• Low pass impulse
This stimulus is also used to measure low pass devices.
The frequency domain data should extend from DC
(extrapolated value) to a higher value, the maximum
frequency determined by the test set. The time domain
response shows changes in the parameter value versus
time. The impulse response can be used for reflection
or transmission measurements.
• Bandpass impulse
The bandpass impulse stimulates a pulsed RF signal (with
an impulse envelope) and is used to measure the time
domain response of band-limited devices. The start and
stop frequencies are selectable by the user to any values
within the limits of the test set used. The bandpass time
domain response also shows changes in the parameter
values versus time. Bandpass time domain responses are
useful for both reflection and transmission measurements.