Kenwood MS-1660 User manual

MS-1660
(DIGITALMEMORY SCOPE)
INSTRUCTION MANUAL

SAFETY
Symbol in This Manual
A
This symbolindicateswhereapplicablecautionary
orotherinformationistobefound.
Power Source
This equipmentoperates from a powersourcethatdoes
notapplymorethan250V rmsbetweenthesupplycon-
ductorsorbetweeneithersupplyconductorandground.
A protectivegroundconnectionbywayofthegrounding
conductorinthepowercordisessentialfor safe operation.
Grounding theProduct
This equipmentisgrounded through thegroundingcon-
ductorofthepowercord.Toavoidelectricalshock,plug
thepowercord into a properlywiredreceptaclebefore
connectingtotheequipment input or output terminals.
Use theProperPowerCord
Use onlythepowercordandconnectorspecifiedforyour
product.
Use theProper Fuse
To avoidfirehazard,usea fuseofthecorrecttype.
DonotOperatein Explosive Atmospheres
To avoidexplosion,donotoperatethisproductinanex-
plosive atmosphere.
DonotRemoveCoverorPanel
To avoidpersonalinjury,donotremovethecoverorpanel.
Refer servicingtoqualifiedpersonnel.
VoltageConversion
Ifthepowersourceisnotappliedtoyourproduct,contact
yourdealer.Toavoidelectricalshock,donotperform
thevoltageconversion.
CONTENTS
SAFETY 2
FEATURES.... 3
SPECIFICATIONS 4
PREPARATION FORUSE6
CONTROLS ANDINDICATORS7
FRONT PANEL 7
REAR PANEL 14
OPERATION 16
OPERATION ASAN OSCILLOSCOPE 16
(1)NORMAL SWEEP DISPLAY OPERATION18
(2)MAGNIFIED SWEEP OPERATION 18
(3) X-Y OPERATION 18
MEMORY SCOPE OPERATION19
(1)WAVEFORM OBSERVATION 19
(2)READINGTOPEN RECORDER 21
(3) CONTROLBY GP-IB 21
APPLICATION 23
APPLICATION ASAN OSCILLOSCOPE 23
APPLICATION ASA DIGITALMEMORY SCOPE... 32
Power InputVoltageConfiguration34
2

FEATURES
The digital memoryscopeMS-1660consistsofaDC-20MHz
bandwidth,dual-traceoscilloscope with a built-in digital
memory.Thememoryfeaturesa capacityof8 bitsx 2048
wordsperchannelanda maximumwritespeedof1 JUS/
word.The unit providestheabilitytostoreandreproduce
sporadic, transientandrepetitiveevents,andrearthe
storedsignalsouttoa penrecorder, through simpleopera-
tion.
The contentsofthememorycanbereadoutor written
via GP-IB sothatexternaldatacanbemonitoredonthe
CRT screenbystoringthedatainthememory. Since an
independentsamplingclockisprovidedforeach
channel, separatesignalscanbestored with separate
clocks atthesametime,andthesamesignalscanbe
storedata lowspeedanda highspeedatthesametime.
A singletracecanbeusedas4Kwords.
1. Foreachtrace,a memoryspaceof2kwordsispro-
vided. The unit hastwoindependentsemiconductor
memoriesof8 bitsx 2048words each.
2. Dualchannel
Inputconsistsoftwoeventsata time,eachallotted
an independentmemory space. Maximumwritespeed
is 1 jus/word.
3. Dualclock
Two completelyindependentsamplingclocksarepro-
videdtoallowsimultaneousstorageoftwo totally
unrelatedsignals.Also,thesamesignalcanbestored
atlowspeedandhighspeed(equivalentofpartial
magnification)atthesametime.
4. Minusdelayfunction
The unit iscapableofstoringthesignalsproduced
beforea triggerpulse,whicharenotobservableon
oscilloscopes.
The dataafterthedelayset point canbeobservedon
theotherchannel,bymagnificationorcontraction.
The delayset point iscontinuouslyvariable with cursor
indication.
5. Hardcopy
The penrecorderprovidedcanbeusedtoproducethe
hardcopyofthedisplayedwaveform from memory.
Inaddition,penfreerunfunctionisprovidedforauto-
matic repetition ofsignalstorageandcorresponding
hardcopyreproduction.
6. Twostoragemodesareselectable.Therefreshmode
initiates writing with a triggersignal.Inthepretrigger
mode,theterminationof writing iscontrolled with a
triggersignal,ineithermode,thewaveform following
thecursor point canbeviewedinmagnifiedorcontract-
ed form intheotherchannel.
7. Free runfunctionforautomatic repetition ofread/write
operations
Once written,thesignalsareheldina readstateforup
to20sec,thenentera writablestateinwhichthe
signals waitfora triggersignal. This cycleisrepeated
automatically.
8. Memorybackupfunction
Signals storedremainunchangedinthememoryeven
after turning poweroff. Thus waveformsmaybe ana-
lyzed atanytimeonlater days.
9. Withthe GP-IB interface,thedata within inmemorycan
besentout,andexternaldatacanbe written inthe
memoryfordisplayonthe screen.
10. Linesynchronizationfacilitatestheobservationand
storageofthesignalsthataretriggered with theline
frequency.
11. BysettingthemodetoX-Y,the unit changestoanX-Y
oscilloscope with a one-button operation.
12. A rectangular,largesizedCRT with widerdisplay
area providesfull-screensignalobservation.
13. Thevertical axis providesa highsensitivityof1 mV/div,
plusa widebandrange from 5mV/divtoa desiredset-
ting.
14. The unit iscapableofhigh-speedsweepof20ns/div.
15. A 150mmrectangularCRT with internalgraticule
(domedmeshtype,post-acceleration with 6kVacceler-
ationvoltage)provides easy waveformobservation
without parallax.
16. The0,10,90,and100%marksonthescreenprovides
easy measurementofrisetime.
17. Theangleofhorizontaltracecanbeeasilycorrected
with trace rotation controlsonthe front panel.
18. The scale illuminationfacilitatesmeasurementina
darkplace,andalsoenablesphotographicrecording
oftheon-screenwaveform.
19. Withtheautomaticfreerunfunction,thetracecanbe
checked whilenosignalisfed.
20. CH1 OUTPUT terminalsareprovidedto monitor the
input signalsontheCH1.
3

SPECIFICATIONS
4
CRT
Model:150 FTM31: Rectangular, with
internalgraticule
Acceleration voltage:6 kV
Display area: 8 X10div(1div= 10mm)
VERTICAL AXIS(CommontoCH1andCH2)
Sensitivity: 1 mV/divto5V/div± 3%
Attenuator:5 mV/divto5V/div
1 -2-5 sequence, fineadjust-
mentbetween10ranges
Inputimpedance:1 MSI ± 2%,Approx.25pF
Frequence responce:
DC: DCto20MHz(Within- 3 dB
at5 mV/divto5V/div)
DC to10MHz(Within-3dB
atX5 GAIN)
AC: 5 Hzto20MHz(Within-3dB
at5 mV/divto5 V/div)
5 Hzto10MHz(Within-3dB
atX5 GAIN)
Rise time X1: Less than17.5ns
X5 GAIN: Less than35ns
Crosstalk: Less than-40dB(CH1& CH2
insamerange)
Operatingmodes:
CH1 CH1, singletrace
CH2 CH2,singletrace
DUAL CH1andCH2,dualtrace
ADD CH1+ CH2(added)display
ALT Dualorquadtracealternating
CHOP Dualorquadtracechopped
X-Y X-Yoscilloscope
CHOP frequency:Approx.250kHz
Polarity reversal: AvailableforCH2only
Maximum input voltage:500Vp.por250V
(dc + acpeak)
Maximumundistorted
amplitude:8 div,minimum
(DC to20MHz)
HORIZONTAL AXIS(Channel2 input,exceptX10MAG)
Modes: X-Ymodeisswitchselectable
CH1: Yaxis
CH2:Xaxis
Sensitivity: Same asvertical axis (CH2)
Inputimpedance: Same asvertical axis (CH2)
Frequency response:
DC: DCto1 MHz(Within-3dB)
AC: 5 Hzto1 MHz(Within-3dB)
X-Y phasedifference: Less than3°at100kHz
Maximumallowable input
voltage: Same asvertical axis (CH2)
SWEEP
Sweep: NORM;Triggersweep
AUTO; Automaticfreerun
functionwhilesignalsarenot
fed
Sweep time:0.2jus/div.to0.5s/div± 3%,
in1-2-5sequence with in20
ranges, fineadjustmentbe-
tween20ranges
Sweep magnification:X10± 5%
Linearity: ± 3%(0.2jus/div± 5% with
X10 magnification)
TRIGGERING
CH1: Triggered with vertical input
signal onCH1.
CH2: Triggered with vertical input
signal onCH2.
EXT: Triggered with external
synchronizing signal.
LINE: Triggered with linefrequency
External triggering:
Inputimpedance:1 Mft± 2%,Approx.25pF
^Maximum input voltage:50V (DC+ ACpeak)
Couplingmodes:AC, HFREJ , DC
Sync sensitivity
PROBE CALIBRATING VOLTAGE
0.5V ± 2%ofpositivesquare wave, approx.1 kHz
INTENSITY MODULATION
Inputvoltage:Intensity increases with TTL
level.
Inputimpedance:Approx.10kft
Frequency range:DCto5 MHz
Maximum input voltage:50V (DC+ ACpeak)
VERTICAL AXISCH1signal output
OUTPUT
Outputvoltage:Approx.50mV/div(50ftload)
Outputimpedance:Approx.5012
Frequency response:
X1: 100Hzto20MHz(within± 3
dB), at50ft load
X5 GAIN: 100Hzto10MHz(within±3
dB),at 50ftload
SYNC
SYNC. FREQ.
MIN. SYNC AMPLITUDE
(VOLTAGE)
COUPLING
RANGE
INT EXT
DC DC
~ 20MHz
1 div 0-1vp.p
AC
10Hz ~ 20MHz 1 div 0-1vp.p
DC
HFREJ
At1.5kHzorover,min.amplitude(voltage)
requiredfor sync increases.

5
GATE OUTPUT
Outputwaveform:Positivepulsetriggeredto
sweep
Outputvoltage:TTLlevel
Series resistance:Approx.22012
DATA CONVERTER
Convertingmethod: Successive comparison,
A/D converter
Conversion speed:1 jus/word
Resolution: 8 bits (0.4%)
Frequency response:DCto250kHz(within-3dB)
MEMORY
Memorycapacity:8 bitsX 2048words/CHX2
(Full memorycapacityof4096
words)
Memorydevices:C-MOSstaticRAMs
Writespeed:1 Ms to100ms/word, with
1-2-5stepsin16ranges(with
independentchannelsetting)
Read speed
INT: MEMORYOUT:1 jus/word
(fixed)
SCOPE: 1 /is/word(fixed)
FOR PEN: 10,20,50ms/word
(3 ranges)
EXT: TTLlevel,repetitivesquare
wave of less than1 MHz
High-levelpulsewidth;
Morethan500ns
Low-level pulsewidth;
Morethan500ns
Rise time; Less than500ns
FREEZE function:Rewrite-protectableforeach
channel
Memorybackup:Fullmemoryholding.
Holdingtimeofmorethan200h.
OPERATING FUNCTIONS
REFRESH : Writeisstarted with thetrigger
(TRIG START) signal(ormanually).
Write prohibition variabletime
between1 to20sec (DISPLAY
TIME)
PRE TRIG: A writeisstartedmanually.
(MANUAL START) Performspretriggeroperation
(negativedelay)accordingto
cursor setting.Automatic,re-
peatedwrite/readoperations
are available(readtimecanbe
DELAY: set from approx.1 to20 sec).
address issimultaneouslydis-
playedinotherchannel.
Cursor settingCursoriscontinuouslymovable
within addressesbetween2 and
2000 words.
Shiftingresolution1 word
(speed variablein2 steps)
DATA OUTPUT
D/Aconverter: 8-bit resolution
Outputlevel:MEMORYOUT:1.6Vp-p± 3%
relativeto input full scale
FOR PEN:2.0Vp-p± 3%
relativeto input full scale
(Over 1 k!2load)
Outputimpedance:MEMORYOUT:Approx.2212
CONTROL OUTPUT
READ GATE OUT
Outputwaveform:Positivepulseequivalentto1
wordoflastaddress
Outputvoltage:TTLlevel(Commonto both
channels)
Series resistance:Approx.22012
READ GATE OUTFORPEN
ControlsignalforPEN
Outputsignal:Negativelogic(activatedabout
2 secafterpenstartON)
Outputvoltage:TTLlevel
Series resistance:Approx.22012
EXTERNAL CONTROL
The datainmemoryiscontrollablevia GP-IB.
Governingstandard: IEEE STD488-1978
Subsets tobe used: SH1, AH1, TE0, LEO, T6,L4,
SR1, RL1, PP0, DC1,andDT0
POWER SOURCE
Line voltage 100/120/220/240Vac ± 10%,
50/60Hz
Power consumptionApprox.70W
DIMENSIONS
Width 426mm(433mm)
Height177mm(190mm)
Depth411mm(475mm)
Figures in( ) includesproject-
ingparts.
WEIGHT Approx.13kg
ENVIRONMENT
Operatingtemperatureand
humidity forguaranteed
specifications: 10to35°C,85%RHmax.
Full operatingtemperature
and humidity range:0 to45°C,85%RHmax.
ACCESSORIES
Probe (PC-20) 2
Attenuation:1/10,1/1
Inputimpedance1/10:10M12,below18pF
1/1: 1 M12,below100pF
Instructionmanual:1
AC powercord:1
Replacement fuse:1
OPTION GP-IB cable (CB-2420P)

PREPARATION FORUSE
SAFETY
Before connectingtheinstrumenttoa powersource,
carefully readthe following information,thenverifythat
theproperpowercordisusedandtheproperlinefuseisin-
stalled forpowersource.Thespecifiedvoltageisshownat
the right sideofthepowerconnectorontherearpanel.If
thepower-cordisnotappliedforspecifiedvoltage,thereis
always a certainamountofdanger from electricshock.
Line voltage
This instrumentoperatesusingac-power input voltages
that100/120/220/240V atfrequencies from 50Hzto
60 Hz.
Power cord
The groundwireofthe3-wireacpowerplug places the
chassis andhousingofthememoryscopeatearthground.
Do notattempttodefeatthegroundwireconnectionor
floatthememoryscopetodosomayposea greatsafety
hazard. Theappropriatepowercordissuppliedbyan
option thatisspecifiedwhentheinstrumentisordered.
The optionalpowercordsareshownasfollowsin Fig. 40.
Line fuse
The fuseholderislocatedontherearpanelandcontains
theline fuse. Verifythattheproperfuseisinstalledby
replacing theline fuse.
EQUIPMENT PROTECTION
1. Before putting thisinstrumentinuse,makesurethat
thepowersourceselectorswitchissettotheproper
positionthatcorrespondstothelinevoltage.Ifthe
selector switchisnotproperlyset,this causes damage
totheinstrument.Connectthepowercordtothe
powerreceptacleonlyafterthisconfirmationismade.
2. TheMS-1660shouldbeinstalledata placemeetingthe
following conditions:
oTheMS-1660isnotexposedtodirectsunlight.
oTemperatureand humidity arenotveryhigh.Theair
does notcontainmanydustparticles,
oThesurroundingfacilitiesandequipmentdonot
produceintensemechanicalvibration,magneticforce,
orimpulsevoltage.
3. Neverapplymorethanthemaximumratedvoltageto
theoscilloscope input jacks.
CH1, CH2 input jacks:
500Vp-p or250V(DC+ ACpeak)
AEXT TRIG, Z AXIS input jacks:
50V (DC+ ACpeak)
Never applyexternalvoltagetotheoscilloscope output
terminals.
4. Whendesiringtoretainthestoredwaveformwhilethe
instrumentispoweredoff,pushthe FREEZE switch
before turning offthepower. Keep the FREEZE switch
pressed whilethepoweristurnedoff.Itisdesirable
tokeepthe FREEZE switchpressedwhentheinstru-
mentispoweredonagaintoreproducethestored wave-
form.Notethat,if input signalsourceisinconnection
with theinstrumentwhenthepoweristurnedon,the
storedwaveformwillbe erased bythewriteoperation
started with an input signal.
The upper3 bitsofthe address switchesfor GP-IB must
be settothelowerpositions.
5. Donot increase theintensitymorethanrequired.
6. Neverallowa smallspotofhighbrilliancetoremainon
the screen forextendedperiodsoftime.
7. WhenusingthisinstrumentinX-Ymode,setthe PULL-
X10MAG switchtothe PUSH position.Ifthisswitchis
set tothe PULL position,thewaveformmaybedisturb-
ed bynoise.
8. Nevercovertheventilatingholesinthetopofthe scope,
as thiswill increase theoperatingtemperatureinsidethe
case.
9. Whenremovingthe case, observethemaintenancein-
structioncontainedinthismanualtopreventa safety
hazard because thisinstrumentcontainshighvoltage
circuits.
10. Always groundtheinstrumentusingthe FRAME sideof
theGNDterminalsontherearpaneltopreventa safety
hazard.
11. When turning onandoffthe POWER switchrepeatedly,
keep anintervalofabout5 seconds. Faster onandoff
operationmay cause malfunctiontotheinstrument.
6

CONTROLS ANDINDICATORS
Fig. 1
FRONT PANEL
©POWER, SCALE ILLUMControl
Turns power on/off andvariesgraticulebrightness.
©POWERLEDPilotLamp
Indicates thatthepowersupplyhasbeenturnedon.
®J=
Groundterminal.
©CAL
Provides a positive0.5Vpeak-to-peaksquarewave
signal ofapprox.1 kHzforprobecompensationadjust-
ment.
© TRACE ROTATIONControl
Electrically rotatesthetracetohorizontalposition.
Used aswhenthetraceis tilted byterrestrialmagnet-
ism.
© FOCUS Control
Used toadjustthetracefor optimum focus.
©INTENSITY/ASTIGControl
INTENSITY: Adjuststhetraceintensity.
ASTIG: Astigmatismadjustmentprovides optimum
spotroundnesswhenusedinconjunction
with FOCUS control
© INPUT Jack
Vertical input forchannel1 traceinnormalsweep
operation.Vertical input forX-Yoperation.
©AC-GND-DCSwitch
Three-positionswitchwhichoperatesasfollows:
AC: Inputsignaliscapacitivelycoupled,blocking
DC component.
GND: Opensthepathbetweenthe input jackand
verticalamplifierssothatthe input ofvertical
amplifierisgrounded. This allowstheearth
potentialtobechecked.
DC: Inputsignalisdirectcoupled,allowingobserva-
tion ofwaveformcontainingDCcomponent.
7

Fig. 2
@ VOLTS/DSV Control
Vertical attenuatorforchannel1.Providesstepadjust-
mentofverticalsensitivityin1-2-5sequence. VARI-
ABLE controlisturnedtotheCALposition,the
calibratedverticalsensitivityisobtained.ForX-Y
operation,thiscontrol serves astheattenuatorfor
Y axis.
@ VARIABLE/PULL X5GAINControls
VARIABLE:
RotationprovidesfinecontrolofCH1vertical sensi-
tivity. Inthefullyclockwise(CAL)position,the
verticalattenuatoriscalibrated.ForX-Yoperation,
thiscontrol serves for X-axis attenuationfineadjust-
ment.
PULL X5 GAIN:
Whenpulledout,the VOLTS/DIV settingis multiplied
byfive,andforX-Yoperation,the X-axis sensitivity
is multiplied accordingly.InX5GAINmode,increas-
edverticalgainmakesthetracethiker.
@y POSITIONControl
RotationadjustsverticalpositionofCH1waveformon
the screen. ForX-Yoperation,thiscontroladjustsY
axis position.
Inmemoryscopeoperation,thecontrolprovidesDC
OFFSET adjustmentofCH1,superimposingtheDC
level over input signal.
Clockwise rotation ofthecontroladds+DCleveltothe
GND level.Counterclockwise rotation adds-DClevel
totheGNDlevel.
@y MEMORYPOSITIONControl
Adjusts theverticalpositionofthestoredwaveform.
Withselectionofthe SAMPLING CLOCK A Control,
thiscontroladjuststheverticalpositionofthestored
waveform.FormemoryoperationinX-Ymode,the
controladjusts Y-axis position.
NOTE:
This controlhasnoeffectonMEMORYOUTA @ jack.
@ INPUT Jack
Receives CH2vertical input, or X-axis input inX-Y
operation.
©AC-GND-DCSwitch
Selects thecouplingofchannel2 vertical input signal.
InX-Yoperation,theswitchprovides input selection
of X-axis andperformsthesamefunctionas AC-GND-
DC®for CH1.
@ VOLTS/DIVControl
Vertical attenuatorforCH2.Providesthesamefunc-
tion as VOLTS/DIV Control© forCH1.InX-Y
operation,thecontrol serves asthe X-axis attenuator.
@ VARIABLE/PULL X5GAINControl
Provides thefinecontroloftheverticalattenuationfor
CH2 andincreasestheverticalsensitivity.Thecontrol
performsthesamefunctionas VARIABLE/PULLX5
GAIN Control(R)forCH1.InX-Yoperation,the
controlprovidesthefineadjustmentofthe X-axis
attenuationandincreasesthe X-axis sensitivity.
8

@ ^ POSITIONControl
For CH2,thecontrolprovidesthesamefunctionas
^ POSITION Control@ forCH1.InX-Yopera-
tion,thecontrolprovides X-axis positionadjustment.
Inmemoryscopeoperation,thiscontrolprovidesDC
OFFSET adjustmentforCH2.
@ ^MEMORYPOSITIONControl
Withselectionofthe SAMPLING CLOCK B control,
thiscontroladjuststheverticalpositionofthestored
waveform.FormemoryoperationinX-Ymode,the
controladjuststhe X-axis position.
NOTE:
This controldoesnotworkforMEMORYOUTB @ jack.
@ MODESwitch
Selects theoperationmodeofthevertical axis.
CH1: Onlythe input signaltochannel1 isdisplayed
onthe screen. Inmemoryoperation,a
differentdisplayisproducedonthescreen
accordingtotheselectionof NORM/DELAY
selector of DISPLAY MODE@ switches.
NORM: Thewaveformstored with SAMPLING
CLOCK A isdisplayedonthe screen.
DELAY:The waveformsstored with SAMPLING
CLOCK A andB aredisplayedasdualtraces
onthe screen.
CH2: Onlythe input signaltochannel2 isdisplayed
onthe screen. Inmemoryoperation,a dif-
ferentdisplayisproducedonthescreen
accordingtotheselectionof NORM/DELAY
selector.
NORM: Thewaveformstored with SAMPLING
CLOCK B isdisplayedonthe screen.
DELAY: The waveformsstored with SAMPLING
CLOCK A andB aredisplayedasdualtraces
onthe screen.
DUAL: The input signalstochannel1 andchannel2
are displayedonthe screen. Inmemory
operation,thewaveformsstored with SAMPL-
ING COCK A andB aredisplayedonthe
screen.
DELAY operationwillnotbeproducedbut
onlyNORMoperationwillbeperformedeven
ifthe NORM/DELAY selectorissetto
DELAY.
ADD: ThealgebraicsumofCH1andCH2signalsis
displayedonthe screen. WhentheCH2INV
21 button isengaged,thedifferencebetween
CH1 andCH2signalsisdisplayed.
Inmemoryoperation,a differentdisplayis
producedaccordingtotheselectionof
NORM/DELAY selector.
NORM: Thescreendisplaysthewaveformwhichis
stored with SAMPLING CLOCK B asthe
ialgebraicsumofCH1andCH2signals(oras
thedifferencebetweenCH1andCH2signals
whenCH2INVisselected).
DELAY: Thescreenprovidesa dualtracedisplaythe
wave formswhicharestored with SAMPL-
ING CLOCK A andB asthealgebraicsumof
CH1 andCH2signals(orasthedifference
betweenCH1andCH2signalswhenCH2INV
is selected).
X-Y: TheinstrumentoperatesasanX-Yoscillo-
scope with CH1servingas Y-axis andCH2as
X-axis.
Inmemoryoperation,thewaveformstored
with SAMPLING CLOCK A isdisplayedas
Y-axis input, andthewaveformstored with
SAMPLING CLOCK B isdisplayedas X-axis
input.
The DELAY operationwillnotbeproduced
butonlytheNORMoperationwillbepro-
ducedevenifthe NORM/DELAY selectoris
set to DELAY.
J-ALT/m CHOP Selector:
Selects thedisplaymodefortwotracesinthe
DUAL mode.
JL ALT:CH1andCH2aignalsarealternatelydisplay-
ed.
m CHOP: CH1andCH2signalsaredisplayedbychop-
ping.
Inmemoryoperation,thealternatesweep
modeisautomaticallyselectedregardlessof
thesettingofthisselector.Settingtodisplay
thestoredwaveformonthe screen.
NOTE:
Each ofthemodesettingcontrolsisrelatedtothe writing
into memory.Seethedescriptionson DISPLAY MODE,
REFRESH/PRE TRIG, NORM/DELAY, SAMPLING
CLOCK A,B,and CURSOR.
@ CH2INVButton
Inverts thepolarityofCH2signal.
@ EXTTRIG Jack
Whenthe SOURCE controlissettotheEXTposition,
thesweepistriggeredbythe input signalfed through
thisjack.
@ LEVEL/PULL SLOPE (-)Control
LEVEL: Adjuststhetriggerlevel,i.e.,the point onthe
triggersignalwaveformslopewherethesweep
starts.
PULL SLOPE:
Adjusts thepolarityofthetriggering.When
thecontrolispulledout,thetriggeroccurs
atthetrailingedgeofthe input waveform.
@ COUPLINGSwitch
Selects thecouplingforthe triggering signal.
9

Fig. 3
AC: The trigger signaliscapacitivelycoupled with
the trigger circuit.
The DCcomponentof input signalisblocked.
HFREJ: TriggersignalisDCcoupled with the trigger
circuit.
AC componentsover1.5kHzareattenuated
forstable triggering oflow-frequencycom-
ponents.
DC: The trigger signalisDCcoupled with the
trigger circuitinsucha wayastogivea trig-
geringwhichincludestheeffectsofdccom-
ponents.
@ TRIG'DLamp
Lightsupwhenthe triger signalisfedandreachesthe
triggering rangeset with the LEVEL control (23).
@ SOURCE Switch
Allowsselection from three triggering modes.
CH1: CH1vertical input signalbecomesa trigger
signal.
CH2: CH2vertical input signalbecomesa trigger
signal.
EXT: Signalappliedat EXT.TRIG (22)jackbe-
comes a trigger signal.
LINE: Linefrequencyofthecommercialsource
becomesa trigger signal.
(27)TRIGGERINGMODESwitch
Selects triggering mode.
AUTO: Triggeredsweepoperation. Even without a
trigger signal,the unit performsfreerun,
showinga trace.
NORM: Normal triggered sweepoperation.Notrace
will bepresentedwhena proper trigger signal
is absent.
Whilethestoredwaveformisdisplayedonthe
screen, onlythestoredwaveformisdisplayed
onthescreen without performing theNORM
operation.
(28) SWEEP TIME/DIVControl
Selects thesweep time in20steps from 0.2/is/divto
0.5s/div.Thesweep time will betheindicationvalue
calibratedattheCAL position (fullclockwise)of
VARIABLE (2§). Whilethestoredwaveformisdis-
puted onthe screen, theindicationonthis control
has noeffect.
@ VARIABLE Control
Provides finesweep time adjustmentcontinuously
betweentherangesofthe SWEEP TIME/DIV Control
(28) . Thesweep time iscalibratedintheCAL position
(fullclockwise).Whilethestoredwaveformisdisplay-
edonthe screen, this control hasnoeffect.
(30)ikPOSITION/PULLXI0MAGControl
4k POSITION:
Rotationadjustshorizontal position ofthe
waveform.
PULL X10MAG:
Provides 10timesfastersweep time when
pulledout.
10

@)SAMPLING CLOCK A,B Controls
Select a samplingfrequencyforthe input signalin
16 rangesbetween100msand1 jus/word.Between
the100msand1 jus/wordrange,thewaveformcanbe
observed during writeoperationbecausethe input
signalisreadoutwhilethe input signalis written in
memory.Betweenthe50{is and1jus/wordrange,a
traceisdisplayed during writeoperationbecausethe
waveformisreadoutafterthewriteinthememory
(2 Kw)hascompleted.
Therefore, whena continuous trigger waveformisfed,
theread time cannotbemaintained,producingdis-
continuedwaveformora traceonthe screen, butthe
waveform will bestorednormally.Whensucha
condition ispresent, pull the PULLDISPLAY TIME
knob39tomaintainthereadtime.
Whenthe DISPLAY MODEselector@ issetto
NORM, SAMPLING CLOCK A correspondstothe
CH1 input signal,andthe SAMPLING CLOCK B tothe
CH2 input signal.Whenthe DISPLAY MODEselector
is setto DELAY, SAMPLING CLOCK A andB cor-
respondtothe input signalofthemainchannelselect-
ed with theMODEselector@ . The DELAY posi-
tion of that modeselectorcorrespondstoNORM.
Fully clockwise rotation ofthe SAMPLING CLOCK
A control makesa connectiontothereadonlyEXT
CLOCK terminals;consequently,thecontentsofthe
memoryarereadout with theclocksignal that isfed
from theEXT CLOCK terminal@ ontherearpanel.
This modeisusedonlyforreadoperationso that the
instrumentisfrozenformemoryprotection, with the
FREEZE lampbeingon.Fullyclockwise rotation of
the SAMPLING CLOCK B control providesconnection
with GP-IB, therebyallowingthereadingand writing
ofmemorycontentsbyconnectingthe GP-IB control-
lertothe unit. (Fordetails,refertothedescriptionon
GP-IB.)
(32) DISPLAY MODESwitches
The MS-1660operatesasa dual-traceoscilloscopeby
thepushof OSCILLO andasa memoryscopewhen
REFRESH or PRETRIG isselected.
Combinationsofswitchsettingsallow four modesof
writing input signal into memory.
REFRESH-NORM:
A writetomemoryisstartedbya trigger
signalormanuallybythepushof WRITE/
PEN START (37). After2048wordshave
beenwritten,thewriteoperationstops,and
the unit waitsinreadstateforthenext trigger
signalormanualstart.
REFRESH-DELAY:
A writetomemoryisstartedbya trigger
signalormanuallybythepushof WRITE/
PEN START (37)andcontinues until 2048
wordshavebeenwritten.Thedataafterthe
cursor point (delaysetting point) aretransfer-
redtotheotherchannel:accordingtothe
samplingclockof that channel,thesedataare
written by2048words into thememory
allocatedto that channel.Aftercompletion
of writing for both channels,the unit waitsin
readstateforthenext trigger signalormanual
start.
This combinationprovidesthesamemodeas
REFRESH-NORM whenMODE@)issetat
DUAL. WhenMODE@)isatADD,thedata
following thecursor point are written toCH1
accordingtothe SAMPLING CLOCK A.
PRE TRIG-NORM:
A writetomemoryis initiated bypressing
WRITE/PEN START button @ . The point
set by CURSOR switch(3^)becomesthe
memory's trigger address,andthewriteopera-
tion continues until thenumberofwords
"(2K words)— (wordsspecifiedbycursor
setting)"havebeen written after input of
trigger signal.Thenthe unit waitsinroad
state until WRITE/PEN START @)isnext
pressed. (PULL DISPLAY TIME @)mustbe
OFF.) This modepermitsobservationofthe
waveformprecedingthe trigger signal.
WhenMODE@ issetat DUAL, CH1per-
formstheaboveoperation.CH2terminates
itswriteoperation upon completionofCH1
writeoperation.
PRE TRIG-DELAY:
The channelspecifiedbyMODE(20)per-
formsthesameoperationasinthePRE
TRIG-NORM mode.Thedataafterthecursor
point (delaysetting point) aretransferredto
theotherchannel;accordingtothesampling
clockof that channel,thesedataare written
by2048words into thememoryallocatedto
that channel.Afterdataare written for both
channels, the unit waitsinreadstateforthe
nextpushofthestart button. (PULL DIS-
PLAY TIME 6|mustbe OFF.)
The MODE@ issetat DUAL, CH1per-
formsthesameoperationasinthePRE
TRIG-NQRM mode.CH2startsa writeto
memory from thecursor point (i.e., trigger
point forCH1)andstopsthewriteoperation
when2048wordshavebeenwritten.
(33)8 DIV/4DIVSelector
Provides a 1/1and1/2 output levelsofthestored
waveformwhichisdisplayedonthescreenandtaken
attheMEMORYOUTjackontherearpanel.
With this button notpressed,the output level will be
1.6Vp-p(at full input scale). With this button pressed,
the output level will behalvedto0.8Vp-p(at full
input scale).
The selectiondoesnotchangetheresolutionofthe
vertical axis.
Therefore, thewaveformsoftwoeventsarecon-
venientlyobservedbyselectingthe4DIVposition.
11

@ CURSOR Switch
Displays thebrightspot(cursorpoint)onthemain
channel sideaccordingthecombinationsofsettingsof
MODE (20)and DISPLAY MODE(32). Cursormove-
mentisintwo speeds. Thatis,whentherightorleft
button ispressedonce,thecursorpointmovestothe
rightorleft,respectively,byoneword;holdingthe
rightorleft button depressedmovesthecursorcon-
tinuouslytothecorrespondingdirectionasfarasthe
button is depressed. Thecursorpointwillstopupon
arrival attherightorleftend.Thecursorpointis
movable between2 and2000words(memory address).
The cursorpointdisplaymodeisavailabletothe
followingcombinations:
\Display
\mode
ModeV
REFRESH PRE TRIG
\Display
\mode
ModeV
NORM
DELAY NORM
DELAY
cm -
Cursor point
onCH1side
Cursor point
onCH1side
Cursor point
onCH1side
CH2 -
Cursor point
onCH2side
Cursor point
onCH2side
Cursor point
onCH2side
DUAL
--
Cursor point
onCH1side
Cursor point
onCH1side
ADD -
Cursor point
onCH2side
Cursor point
onCH2side
Cursor point
onCH2side
X-Y
- - - -
(35) PEN/SCOPE, FREE RUN Selectors
PEN/SCOPE:
Selects the output directionofthememory
contents, to SCOPE or PEN. Thereadspeed
varies with each selection. Pressing the button
sets theunit into thePENmode(andthe
MEMORY OUTterminalontherearpanel
willbeswitchedaccordingly).
When thePENmodeis selected, press PEN
START @), andaftera preparatoryperiod
ofabouttwo seconds, thememorycontents
are fedouttoFORPEN(46)atthespeedset
withPEN SPEED @ (10mst 50ms/word).
This switchshouldnotbechangedtothePEN
modeduringa write.Ifsochanged,the
properwaveformmaynotbeobtained.
FREE RUN:
This modeautomaticallyrepeatsa writeto
memoryanda readtoFORPEN(^6).Asthe
writetomemory,controlledbya trigger
signal, iscompleted,thePENmodeisauto-
matically selected. Then, inabouttwo
seconds ofpreparatoryperiod,signalsare
outputtedtoFORPEN(46), andaftercom-
pletionoftheoutput,theunitagainenters
thetriggerwaitstate.
NOTE:
The properwaveformmaynotbeobtainedifthisswitchis
changed tothe FREE RUNmodewhilethememorycon-
tentsarefedouttotheFORPENA,B jacks withPEN
START button inthePENmode.So,donotchangethe
settingofthisswitchduring output operation.
@FREEZE button
Freezes, i.e.,suspendsthewritethe into memory.
Pressing theA sidestopsthewriteoperationonthe
memorywhichiscontrolledby SAMPLING CLOCK
A (31), withtheresultthatthedatawillberetained
inthememory. Pressing theB sidestopsthewrite
operationonthecorrespondingmemory.Whenthis
switch is pressed, thewriteA orB (38)lamplightsup,
indicatingthatthewriteoperationisapparentlyper-
formed,butthewriteoperationisactuallysuspended.
Withthepushofthe FREEZE switch,thegreenLED
ontheleftwill light up.
@ WRITE/PEN START Button
When PEN/SCOPE switch(35)issettothemonitor
mode,this button serves asa manualstart button for
writetomemory.If DISPLAY MODE(32)issetto
REFRESH, thepushofthis botton isinterpretedas
a trigger signal; if DISPLAY MODE(32)issetto PRE
TRIG, thepushofthis button startsa writeto
memory,andaftercompletionofthewrite,theunit
enters thetriggersignalwaitstate.
When PEN/SCOPE switch(35)issettothepenmode,
this button ispressedto output signalstoFORPEN
(^6). Actually,thesignal output beginsabouttwo
seconds afterthe button is pressed.
@ WRITEA B, READ LEDs
These LEDs indicatewhethertheunitisinthe WRITE
or READ state.Normally,directoryaftertheunit
is poweredon,the READ (green)LEDlightsupto
indicatethe READ state.Whenthe WRITE/PEN
START (37) button ispressedorthewriteoperation
is startedbya trigger signal, the WRITE A orB (red)
LED lamplightsuptoindicatethewritestate.
(39) PULL DISPLAY TIMEKnob
Afterbeingpulled,thisknobisturnedcounterclock-
wise tomakethetimesettinglongerandclockwiseto
make itshorter.Thetimecanbesetfromabout1 to
20 seconds. Theunitperformsdifferentoperations
dependingonwhether DISPLAY MODE(32)issetat
REFRESH or PRETRIG.
REFRESH:
The readtimeperiodaftera writeissetbythe
PULLDISPLAY TIME knobintherangeof
about1 to20 seconds. Duringthisperiod,
theunitisinread-onlystate,thatis,a write
does nottakeplace because anytiggersignal
is ignored.Aftertheendofthesetperiod,
theunitentersthetriggerwaitstate,readyto
12

Fig.
execute thenextwriteuponreceiptofa
triggersignal.
PRE TRIG:
A writetomemoryisstartednotbymanual
startbutattheintervalsetbythe PULL
DISPLAY TIME knob.Uponreceiptofa
triggersignal,theunitperformsa PRE TRIG
operation,andaftertheelapseoftheset
interval, restartsa writetomemory.
If,inthismode, WRITE/PENSTART (37)is
pressed, thewriteoperationmaystop.When
using manualstart,therefore,ensurethatthe
PULLDISPLAY TIME button is OFF. Inthe
event ofanunwantedstopofwriteoperation,
thestopcanbecancelledbysimplypushing
an thenpullingthe PULLDISPLAY TIME
button.
(40)PEN SPEED Selector
With PEN/SCOPE @ selectorsettothePENposition,
thisswitchbecomeseffectivetoselecta readspeedof
thePEN output in3 steps: 10,20,and50ms/word.
@ GP-IB LEDs
The four LEDs indicatethestateoftheunitwhenit
is controlledbya GP-IB. Whenlit,eachLEDprovides
thefollowingindication:
SRQ: Theunitisinservicerequestmode.
TALK: Theunitisaddressedasthetalker.
LISTEN: Theunitisaddressedasthelistener.
REN: Theunitisinremotemode.
13

REAR PANEL
Fig. 5
@ SWEEP GATE Jack
The positive-pulsegatewaveformsynchronized with
thesweepis outputted here.
(43) Z AXISINPUT Jack
External intensity modulation input; TTLcompatible.
Positive voltage increases theintensity.
@ CH1OUTPUT Jack
CH1 vertical output connector, providing a capacitively
coupledsignal.Usedasinfrequencymeasurementby
connectinga frequencycounter. Cascade connection
for CH1 and CH2 isnotallowed.
@ MEMORYOUTA,B Jacks
The dataforA andB storedintheirmemoriesare
taken atthese jacks afterbeingconverted into analog
form.
When theMODEswitchissettoADDandthe DIS-
PLAY MODEselectorissettoNORM,theadded
output signalisfedonlytotheB jack.
@ FORPENA,B Jacks
Output (analog)signalconnectorsfora penrecorder.
The datastoredbyusingthe SAMPLING CLOCK A
control isfedtotheA connector,andthedatastored
byusingthe SAMPLING CLOCK B isfedtotheB
connector. These connectorsareonlyeffectiveinPEN
mode.
NOTE:
Itisimpossibletoseta PEN SPEED valueand ON/OFF
state foreitherjackindependentlyoftheother.
(47) READ GATE OUT Jack
The positivepulsecorrespondingtotheonewordof
thelastaddressinthememoryisfedtothisconnector.
The output signal from thisconnectorcanbeusedasa
trigger signalwhenreadingviatheEXT CLOCK
connector.
@ READ GATE OUTFORPEN Jack
This connectorisusedto control a penrecorderor
otherdevice. This connectoriseffectiveinPENmode.
With thePEN START button pressed, thesignalisfed
atlowlevel(TTL level).
(49)EXT CLOCK Jack
External clock input connectorforreadonly. This
connectorisused with the SAMPLING CLOCK A
switch settoEXT.
(50) GP-IB Connector
When connectingthisinstrumenttothe GP-IB inter-
face thepiggybackcableisconnectedhere.Connec-
tion ordisconnectionmustbedoneonlyafterthe
GP-IB controllerispoweredoff.
14

(ST)GNDTerminal
The groundterminalsfor GP-IB connection.Whenthe
shortbar(metal fitting) isconnectedbetweenthese
terminals, theGNDlineinthe GP-IB connectorwillbe
groundedtothe case.
(52) ADDRESS Selector
GP-IB addresssettingswitch,representingaddressbits
1 through 5 from the right. This switchisusedtoset
the GP-IB address with fivebinarybits. Each bitbe-
comes "1" whenthecorrespondingswitchpositionis
set totheupperside.Thethreeotherbitpositionson
the left mustbeheldonthelowerside.Ifanyofthese
threeisontheupperside,memorybackupwhenthe
powerisoffcannotbemade.
(53)FAN
Exhausts airtocarrytheheatoutofthe case.
(S)CordWrap
The powercordiswrappedherewhenthe unit is
transportedorkeptinstorage.Thecordwrapsalso
serve asthefeet.
(55)PowerConnector
The powercordprovidedispluggedhere.
(56)VoltageSelector
Provides a selectionofAClinevoltages100/120/220/
240 V byinsertionofanappropriateplug.
(57) Fuse Holder
Accommodates a time-lagfuseof1 A for100/120V
supplyor0.5A 220/240Vsupply.
(58)Handle(BeltType)
Used whentransportingthe unit.
(59)Side Legs
Useful wheninstallingthe unit ina narrow spaces or
fortemporaryrestingduringtransport.
15

OPERATION
Before turning onthescope,setthe front panelcontrols
shownbelow.Fora detaileddescriptionofcontrols,see
"CONTROLS AND INDICATORS".
Whenusinga probe,refertoitsinstructionmanual,aswell
as theparagraph "PROBE COMPENSATION" under
"APPLICATION".
Fig. 6
OPERATIONASAN OSCILLOSCOPE
[1]NORMALSWEEP'DISPLAYOPERATION
1. Turnthe POWER switch(T)clockwise— thepower
supply will beturnedonandthe pilot lamp will light.
Set thesemodesasfollows:
VerticalMODE@ : CH1
TRIGGERING MODE@ : AUTO
DISPLAY MODE@ : OSCILLO
2. ThetraceshouldappearinthecenteroftheCRTdis-
play.Ifnot,centerit with POSITION @.Next,
adjustthe INTENSITY ©and,if necessary, the FOCUS
(1T)for ease ofobservation.
3. Applyan input signaltochannelCH1INPUTjack@
andadjust VOLTS/DIV @fora suitable size displayof
thewaveform.
WhenMODEswitch@ issettoCH2andan input
signalisappliedtoCH2INPUT@ aswell,the input
signalforCH2isdisplayedonthescreen through opera-
tionssimilartoCH1.
WhenMODE@)issettoADD,thescreendisplaysthe
waveformrepresentingthealgebraicsumofCH1+ CH2.
IfCH2INV(2?)isthenpressed,thedisplaychangesto
thealgebraicdifferenceofCH1- CH2.
The sensitivity will bethevalueof VOLTS/DIV setting
if both channelsaresettothesame VOLTS/DIV setting.
WhenMODE(20)issettoDUALorALT,thesweep
alternatesbetweenCH1andCH2.
4. Ifthewaveformtobedisplayedcannotbe triggered or
the trigger point istobeshifted, follow the triggering
instructionsgivenbelow.
TRIGGERING
For thewaveformof input signaltobeobserved,itmustbe
heldstationarybyproperly triggering thesweepcircuit.
Triggermaybeinternalwherethecircuitis triggered bythe
input waveformtobeobserved,oritmaybeexternal
wherea signalhavinga certaintime-relationship with the
input signalisappliedtotheexternal trigger terminal.
(1) Theselectionofa signal that serves asthe trigger
signalismadeusingthe SOURCE selector.Inobser-
vationofsomewaveform,theDCcomponentor
high-frequencycomponentsuchasnoisemaynotbe
requiredasthe trigger signal.Therefore,the COUPL-
ING control shouldbeadjustedtothespecific pur-
poses.
16

INTERNAL TRIGGERING
By setting SOURCE selector@ toCH1,CH2,or LINE,
the input signalinthe triggering circuitisconnectedtothe
internal trigger source.
Any input signalcanbeeasilytriggered,becausethe input
signalfedtoINPUT®or(M)isbranchedinthevertical
amplifiertothe trigger circuitso that itactstocreate
trigger signalsynchronized with the input signal,thusdriv-
ingthesweepcircuit.
With the SOURCE selectorsettoCH1orCH2,a trigger
is developpedbytheCH1orCH2signalregardlessofthe
MODE setting. With the SOURCE selectorsetto LINE,
triggering isdelivered from thecommerciallinefrequency.
EXTERNAL TRIGGERING
With the SOURCE selectorsettoEXT,a trigger signal
appliedtotheEXT TRIG jack(2^) serves astheexternal
trigger. External triggering shouldbeusedwhena signal
different from the input signalforthevertical axis isused
fortriggering.Inthis case, the trigger signalmusthavea
certain time relation with thevertical input signal.
Fig. 7 shows input and output signalsobservedwhena gate
signalisfedtoEXT TRIG jack(2^)asa trigger signal(the
sweep circuitisdriven with thegatesignal)and,atthe
same time,theburstsignalproducedbythegatesignal
is fedtothesamplecircuit.
As showninthefigure,external triggering producesthe
proper trigger regardlessofthe input signalto INPUT jacks
(1f)and (14). Thus thereisnoneedof triggering adjustment
even ifthe input signal varies.
Trigger signal
(Gate signal)
CH1 (Inputsignalof
amplifier,etc.)
CH2 (Outputsignalof
amplifier,etc)
(2) Settingofcouplingswitch
AC
The trigger signaliscapacitivelycoupled,soitsDC
componentiscut,givinga stable trigger whichisnot
affectedbytheDCcomponent. With thisadvantage,
this position ofthecouplingswitchisconveniently
selected forordinaryapplications.However,ifthe
trigger signalislowerthan10Hz,the trigger signal
level becomesattenuated,resultingin difficulty in
triggering.
HFREJ
The trigger signalissupplied through a low-pass filter
toeliminatethehigh-frequencycomponent(higher
than1.5kHz),givinga stable triggering with low-
frequencycomponent.Whenhigh-frequencynoiseis
superimposedoverthe trigger signalasshownin Fig.8,
thehigh-frequencynoiseiscuttoprovidea stable
trigger.
Waveform withhigh-frequencynoisesuperimposed
DC
The trigger signalandthe trigger circuitaredirectly
coupledtoallow triggering from DCcomponents. This
modeisuseful I forthe triggering with a low-frequency
waveformbelow10Hzor with a slowlyrepetitive,
sharp edgesignalsuchaslampwaveform.
(3) Afterthe SOURCE hasbeenset,the trigger point can
besetby rotating LEVEL/SLOPE control @.
TRIGGER LEVEL
The trigger point ofwaveformisset with the LEVEL and
SLOPE controls.Fig.9 showstherelationbetween LEVEL
and SLOPE with respectto trigger point. Setthelevelof
the trigger point asrequired.
+ Direction
LEVEL
Fig. 9
17
Trigger signal processed in HFp^j mode
Fig. 8
"-"rangeof SLOPE
"+" rangeof SLOPE
-Direction

AUTO TRIGGER .
With the TRIGGERING MODEselector(27)setto AUTO,
thesweepcircuitissetinthefreerunmodewhilethe
trigger signalisnotpresent.So,auto triggering isuseful
forGNDlevelconfirmation.
When trigger signalisfed,the trigger point canbesetby
usingthe LEVEL and SLOPE controlsasinthe case of
normaltriggering.Whenthe trigger point exceedsthe
trigger range,the unit entersthefreerunmodeandthe
waveform will flow.
Normally(with TRIGGERING MODEsettoNORM),
whenno trigger signalispresentorthe trigger rangeis
exceeded, thesweepisdeactivatedandnotraceisgenerat-
ed.
5. Adjustthe SWEEP TIME/DIV control @ togivea
suitabledisplay.
Adjustthe VARIABLE control @ asrequired.By
doing this,normalsweepdisplayisproduced.
[2]MAGNIFIED SWEEP OPERATION
Since merelyshorteningthesweep time tomagnifya por-
tion ofthewaveformonthescreencanresultinthedesired
portion disappearingoffthe screen, suchmagnifieddis-
playshouldbeperformedusingthemagnifiedsweep.
Procedure:
Usingthe POSITION control @,adjustthedesired
portion ofwaveformtothecenteroftheCRT.Thenthis
control canbepulledouttomagnifythedisplay10times.
For thistypeofdisplaythesweep time isthe SWEEP
TIME/DIV settingdividedby10.
[3]X-YOPERATION
Phase differencemeasurementsmaybemadebyuseofthe
X-Y displaymode.
Procedure:
Set theMODEswitch@ toX-Y.Inthismodethechannel
1 orY input becomesthe Y-axis input, andthechannel2 or
X input the X-axis input forX-Ydisplay.
The vertical position isadjusted with * POSITION @of
CH1, andthehorizontal position is with ^ POSITION (TS)
ofCH2.
X andY sensitivityaresetbyusingthechannel2 and
channel1 VARIABLE and VOLTS/DIV controlsre-
spectively.
18

MEMORY SCOPE OPERATION
[1] WAVEFORM OBSERVATION
Set each controltodisplaythewaveformasinthe case of
an ordinaryoscilloscope.
(1) Set each controlasfollows:
MEMORY POSITION : Center
PULLDISPLAY TIME : OFF
FREEZE : OFF
PEN/SCOPE : SCOPE
(2) Set SAMPLING CLOCK sothatitcorrespondstothe
inputfrequency.(Ifthe SAMPLE CLOCK settingis
lower thantheinputfrequency,analiasingerror
occurs).
(3) Set DISPLAY MODE to REFRESH orPRE TRIG.
REFRESH mode:
When a signalisfedtothe INPUT connectoronthisunit
and exceeds thetriggerlevelsetting,the WRITE LED
lamps A,B will light uptoindicatethatthewriteopera-
tion isbeingperformed.
These LEDlampsrelateto SAMPLING CLOCK A andB;
theirlightingtime varies withthesettingrange(thetime
consumed forwritingoneword into memory)ofthe
SAMPLING CLOCKs.
When SAMPLING CLOCK issettoa CLOCK position
which isslowerthan0.1ms/wordwhilethe WRITE LED
lightsandthewriteoperationisperformed,thewriteand
read operationsaresimultaneouslyperformed.Onthe
screen, theinput signals appearsequentiallyfromtheleft.
When SAMPLING CLOCK issettoa CLOCK position
faster than0.1ms/word,the signals disappearjustfor
moment (less thanapprox.100ms)duringwriteoperation,
butthewaveformisdisplayedinanalmoststablecondi-
tion because thewriteoperationwillbeinstantlycom-
pletedandthereadoperationwillbeimmediatelystarted.
If theinputsignalisa continuouswaveformwithshorter
period (sine wave, triangular wave, rectangular wave, etc.),
thewriteoperationisrestartedbythenexttriggerpulse
immediatelyafterthewriteoperationiscompleted. There-
fore, ifthe SAMPLING CLOCK issettoa CLOCK posi-
tion fasterthan0.1ms/word,thewriteandreadopera-
tionsarecyclicallyperformed,withtheresultthatthe
trace duringthewriteoperationmayappearonthe screen,
producingflicker.Iftoobservethewaveformin such a
condition,performthefollowingadjustment:
By pullingthe PULLDISPLAY TIME controlandturning
it clockwise, therestarttimecanbechangedbycontrolling
the successive trigger pulses. Fully clockwiserotationof
thecontrol disables thenextwriteoperationforabout20
seconds, maintainingthereadstate(theadjustmentis
variable betweenapprox.1 to20 seconds.)
PRE TRIG mode
This modeprovidesthe PRE TRIG (- DELAY) operation
which ispreculiartothedigitalmemory scope.
In thismode,writeoperationisusuallystartedmanually
(by pressingthe WRITE START button).
Writeoperationcan also bestartedrepeatedlyatregular
timeintervalsbyusingthe PULLDISPLAY TIME control.
If thesignalappliedtotheunitisnota continuous wave
butissporadic,thetracedevelopsa flickeringbrightspot
onitsleftend.Thepositionofthebrightspotisthe
guidepointthatrepresentsthetriggerpointafterwrite
(i.e., the address positiononthe screen). Thebrightspot
is movedtotherightorleftbypressingthe CURSOR
switch.
When thewaveformpriortothetriggerpointistobe dis-
played onthelefthaldofthe screen, press the CURSOR
switch untilthebrightspotispositionedtothecenterof
the screen. Afterthispositioning,thepushofthe WRITE
START button (manualstartinthis case) causes lighting
oftheLEDof WRITE A orB (dependingon MODE switch
setting), whichindicatesthewritingoperatingisbeing
performed. ThelightingoftheLEDisindependentofthe
input signal. Iftheinputsignalcomesto exceed the TRIG
LEVEL setting,asindicatedbylightingofthe TRIG'D
lamp, thewritingoperationisterminatedafterwritingof
thefollowinginputwaveform,andthe WRITE A,B LEDs
gooff.Uponthisterminationofwriting,thetriggerpoint
forthewaveformjuststoredmovestothebrightspot
positionedwiththe CURSOR switch.Theunitisthenheld
inreadstate,witha stillwaveformonthe screen. The
result isthatthewaveformbeforethetriggerpointis dis-
played totheleftofthebrightspotonthe screen, andthe
waveform afterthetriggerpointistotherightofthebright
spot.
Given beloware examples of output waveformobtainedin
various modes.
(1) DISPLAY MODE: REFRESH-NORM
1 MODE: CH1orCH2
Waveform ofCH1orCH2
inputsignal(controlled
by SAMPLING CLOCK A
orB)
Waveform ofCH1input
signal (controlledby
SAMPLING CLOCK A)
Waveform ofCH2input
signal (controlledby
SAMPLING CLOCK B)
CH1 andCH2input signals are same, but SAMPLING CLOCK A
is settotwicethe SAMPLING CLOCK B setting.
19
Trigger point
•2048W-
(2) MODE: DUAL
-2048W
Trigger point

3 MODE: ADD
(4) DISPLAY MODE: PRETRIG-DELAY
1 MODE: CH1 or CH2
Synthesized waveformof
CH1 andCH2inputsignals
(controlledby SAMPLING
CLOCK B)
(2) DISPLAY MODE: REFRESH-DELAY
1 MODE: CH1 or CH2
Waveform ofCH1orCH2
inputsignal(controlledby
SAMPLING CLOCK A or
B)
• WaveformofCH1orCH2
inputsignal(controlled
by SAMPLING CLOCK B
orA)
SAMPLING CLOCK A (orB)issettotwicethe SAMPLING
CLOCK B (orA)setting.
3 MODE: ADD
Trigger point
Synthesized waveformCH1
and CH2inputsignals
(controlledby SAMPLING
CLOCK A)
Synthesized waveofCH1
and CH2inputsignals
(controlledby SAMPLING
CLOCK B)
SAMPLING CLOCK B issettwicethe SAMPLING CLOCK A
setting.
Waveform ofCH1orCH2
inputsignal(controlledby
SAMPLING CLOCK A or
B)
2 MODE: DUAL
Synthesized waveformof
CH1 andCH2inputsignals
(controlledby SAMPLING
CLOCK B)
Waveform ofCH1orCH2
inputsigna(controlledby
SAMPLING CLOCK A or
B)
Waveform ofCH1orCH2
inputsignal(controlledby
SAMPLING CLOCK B or
A)
SAMPLING CLOCK A (orB)issettotwicethe SAMPLING
CLOCK B (orA)setting.
Waveformbeforetrigger
Waveform ofCH1input
signal (controlledby
SAMPLING CLOCK A)
Waveform ofCH2input
signal (controlledby
SAMPLING CLOCK B)
CH1 andCH2inputsignalsare same, but SAMPLING CLOCK A
is settotwicethe SAMPLING CLOCK B setting.
Synthesized waveformof
CH1 andCH2inputsignals
(controlledby SAMPLING
CLOCK A)
Synthesized waveformof
CH1 andCH2inputsignals
(controlledby SAMPLING
CLOCK B)
SAMPLING CLOCK B issettotwicethe SAMPLING CLOCK A
setting.
20
Trigger point
2048W
2048W
Cursor point
Trigger point
2048W
Waveformbeforetrigger
Trigger point
= cursor point
2 MODE: DUAL
•2048W-
Trigger point
= cursor point
2 MODE: DUAL
Same operationasin DUAL modeof REFRESH-NORM mode.
3 MODE: ADD
-2048W-
Cursor point
2048W
Waveformbeforetrigger
; Triggerpoint
! = cursor point'
Fig. 10
(3) DISPLAY MODE: PRE TRIG-NORM
1 MODE: CH1 or CH2
-2048W
Waveformbeforetrigger
Trigger point
= cursor point
2048W-
Waveformbeforetrigger
Trigger point
= cursor point
End pointof
CH1 input
write
Waveform ofCH1input
signal (controlledby
SAMPLING CLOCK A)
Waveform ofCH2input•
signal (controlledby
SAMPLING CLOCK B)
CH1 andCH2inputsignalsare same, but SAMPLING CLOCK A
is settotwicethe SAMPLING CLOCK B setting.
2048W
Waveformbeforetrigger
Trigger point
= cursor point