Chapter Data Collection With Time Throughput; Time Throughput With The Hp 3562A; Preparing A Disc For Throughput; Setting Up The Session - HP 3562A Operating Manual

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Chapter
Data Collection with Time Throughput
Time Through put with the H P 3562A
Preparing a Disc for Th rough put
Setti ng Up the Session
M easu rements with T h rough put Data
I ntroduction
A
common testing technique is the gatheri ng of data for later analysis in a lab or
office. Typical recordi ng devices i nclude portable i nstrumentation tape recorders,
h i g h speed tape drives and large-capacity disc drives. Data is played back i nto a
spectrum analyzer or oscilloscope for detailed analysis.
With i n the realm of com puter-based Fou rier analysis systems, this technique is
referred to as data throug h put or ADC through put (where ADC stands for analog-to­
digital converter) . Analog i n put signals are sampled , digitized and then transferred to
a d isc d rive for storage on a mag n etic disc. The stored data is recal led from the disc
as discrete time records for detailed analysis i n the time or frequency domains. This
tech nique is often used i n appl ications where short test times are critical access to
the system-under-test is l imited , or destructive testing is bei ng performed .

Time Throughput with the HP 3562A

Th roug h d i rect control of external H P- I B disc d rives and the Ti me Through put
capability. data through put can be i mplemented with the HP 3562A and an HP disc
d rive. Each time through put i s called a " session " : a session i s stored i n a file (named
by the user) on a disc for later recal l . M ore than 3 2 , 000 time records ( > 1 34 M ega­
bytes) can be gathered in any session-thus, the amou nt of data wh ich can be
gathered in a session is typical ly l i mited by the capacity of the d isc. Real-time or " gap
free" data can be collected for frequency spans as wide as 10 k H z (with Command
Set-80 disc drives such as the HP 7941 ) .
Analysis can b e performed with Linear or Log Resolution and proceeds exactly a s i t
wou ld with analog i n put data. M easu rements are config u red using t h e steps outli ned
in C hapters 2 and 3, i ncluding averag i n g ; if Time Through put is active when the
START key is pressed , data will be recal led from the selected disc file and loaded i nto
the time record for processi ng.
Preparing a Disc for Through put
disc med i a i n itial ized
Before starti ng the t h rough put session,
When the d isc is con nected and a disc i nitial ized , the next step i s the creation of the
throu g h put file or files (although files are reuseable, each session or test requ i res a
new file)
Press the DISC key, then the DISC FCTN (disc functions) softkey.
1 . Disc Fu nctions
2. Create Throughput File
enter the length as a period of time, a number of points or a
number of time records. For this example 40 RECORD (40 time
records) was entered. This entry sets the total size of the
throughput file: 40 time records means up to 40 time records
from a single channel or
measurements.
Select the CREATE THRUPT softkey. The alphanumeric entry
menu will be activated and the front panel keys are redefined as
alpha keys (notice the blue letters and characters at the lower
right of every key except Help). For disc files, up to eight letters
and numbers (no characters, math symbols or punctuation
marks) can be combined to name the throughput file. In this
example the file name USER1 was used.
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Data Collection with Time Throughput
as descri bed in Chapter 1 2 . " Documentation of Results. "
Select the THRUPT SIZE (throughput size) softkey and
from each input for dual-channel
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the d i sc d rive m u st be connected and the