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MEMORY SCOPE OPERATION
[ 1 ] WAVEFORM OBSERVATION
Set each control to display the waveform as in the case of
an ordinary oscilloscope.
(1) Set each control as follows:
M E M O R Y P O S I T I O N
P U L L D I S P L A Y T I M E
F R E E Z E
P E N / S C O P E
(2) Set S A M P L I N G C L O C K so that it corresponds to the
input frequency. (If the S A M P L E C L O C K setting is
lower than the input frequency, an aliasing error
occurs).
(3) Set D I S P L A Y M O D E to R E F R E S H or P R E T R I G .
R E F R E S H mode:
When a signal is fed to the I N P U T connector on this unit
and exceeds the trigger level setting, the W R I T E L E D
lamps A , B will light up to indicate that the write opera-
tion is being performed.
These L E D lamps relate to S A M P L I N G C L O C K A and B ;
their lighting time varies with the setting range (the time
consumed for writing one word into memory) of the
S A M P L I N G C L O C K s .
When S A M P L I N G C L O C K is set to a C L O C K position
which is slower than 0.1ms/word while the W R I T E L E D
lights and the write operation is performed, the write and
read operations are simultaneously performed.
screen, the input signals appear sequentially from the left.
When S A M P L I N G C L O C K is set to a C L O C K position
faster than 0.1 ms/word, the signals disappear just for
moment (less than approx. 100 ms) during write operation,
but the waveform is displayed in an almost stable condi-
tion because the write operation will be instantly com-
pleted and the read operation will be immediately started.
If the input signal is a continuous waveform with shorter
period (sine wave, triangular wave, rectangular wave, etc.),
the write operation is restarted by the next trigger pulse
immediately after the write operation is completed. There-
fore, if the S A M P L I N G C L O C K is set to a C L O C K posi-
tion faster than 0.1 ms/word, the write and read opera-
tions are cyclically performed, with the result that the
trace during the write operation may appear on the screen,
producing flicker.
If to observe the waveform in such a
condition, perform the following adjustment:
By pulling the P U L L D I S P L A Y T I M E control and turning
it clockwise, the restart time can be changed by controlling
the successive trigger pulses. F u l l y clockwise rotation of
the control disables the next write operation for about 20
seconds, maintaining the read state (the adjustment is
variable between approx. 1 to 20 seconds.)
P R E T R I G mode
This mode provides the P R E T R I G ( - D E L A Y ) operation
which is preculiar to the digital memory scope.
In this mode, write operation is usually started manually
(by pressing the W R I T E S T A R T button).
: Center
: O F F
: O F F
: S C O P E
On the
Write operation can also be started repeatedly at regular
time intervals by using the P U L L D I S P L A Y T I M E control.
If the signal applied to the unit is not a continuous wave
but is sporadic, the trace develops a flickering bright spot
on its left end. T h e position of the bright spot is the
guide point that represents the trigger point after write
(i.e., the address position on the screen). T h e bright spot
is moved to the right or left by pressing the C U R S O R
switch.
When the waveform prior to the trigger point is to be dis-
played on the left hald of the screen, press the C U R S O R
switch until the bright spot is positioned to the center of
the screen. After this positioning, the push of the W R I T E
S T A R T button (manual start in this case) causes lighting
of the L E D of W R I T E A or B (depending on M O D E switch
setting), which indicates the writing operating is being
performed. The lighting of the L E D is independent of the
input signal. If the input signal comes to exceed the T R I G
L E V E L setting, as indicated by lighting of the T R I G ' D
lamp, the writing operation is terminated after writing of
the following input waveform, and the W R I T E A , B L E D s
go off. Upon this termination of writing, the trigger point
for the waveform just stored moves to the bright spot
positioned with the C U R S O R switch. T h e unit is then held
in read state, with a still waveform on the screen. T h e
result is that the waveform before the trigger point is dis-
played to the left of the bright spot on the screen, and the
waveform after the trigger point is to the right of the bright
spot.
Given below are examples of output waveform obtained in
various modes.
(1) D I S P L A Y M O D E :
R E F R E S H - N O R M
1
M O D E : C H 1 or C H 2
•2048W-
T r i g g e r p o i n t
(2) M O D E :
D U A L
-2048W
T r i g g e r p o i n t
C H 1 a n d C H 2 i n p u t s i g n a l s a r e s a m e , b u t S A M P L I N G C L O C K A
is s e t t o t w i c e t h e S A M P L I N G C L O C K B s e t t i n g .
W a v e f o r m o f C H 1 o r C H 2
i n p u t s i g n a l ( c o n t r o l l e d
b y S A M P L I N G C L O C K A
o r B )
W a v e f o r m o f C H 1 i n p u t
s i g n a l ( c o n t r o l l e d b y
S A M P L I N G C L O C K A )
W a v e f o r m o f C H 2 i n p u t
s i g n a l ( c o n t r o l l e d b y
S A M P L I N G C L O C K B )
1 9
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