JYE Tech FG085 Function Generator User manual

DN085-01v06
JYE Tech-1-www.jyetech.com
FG085 miniDDS Function Generator
ManualofOperation
ApplicableModels:08501,08501K,08502K,08503,08503K, 08504K
ApplicableFirmwareVersion:1)113-08501-130orlater(forU5)
2)113-08502-050orlater(forU6)
1. Getting Started......................................................................................................................1
2. FrontPanelFeatures.............................................................................................................2
3. Connectors............................................................................................................................4
4. FG085 Operations.................................................................................................................6
ContinuousWaveform(CW)Mode...............................................................................................................6
Frequency..............................................................................................................................................7
Amplitude..............................................................................................................................................8
DC Offset...............................................................................................................................................8
IncrementalAdjustment.........................................................................................................................8
DutyCycle.............................................................................................................................................8
TriggerFunction....................................................................................................................................9
FrequencySweepingMode...........................................................................................................................9
Rangeand Rate....................................................................................................................................11
SweepDirection..................................................................................................................................12
TriggerFunction..................................................................................................................................12
SyncPulse Output...............................................................................................................................12
Amplitude............................................................................................................................................12
DC Offset.............................................................................................................................................12
ServoPositionMode...................................................................................................................................13
Pulse Widthand...................................................................................................................................14
Pulse Amplitude...................................................................................................................................14
Incrementand......................................................................................................................................14
ServoSignalSettings...........................................................................................................................15
ServoRun Mode..........................................................................................................................................15
States...................................................................................................................................................16
ChangeSettings...................................................................................................................................16
ArbitraryWaveformGeneration (AWG).....................................................................................................16
HowIt works.......................................................................................................................................16
DefineWaveformFile.........................................................................................................................17
DownloadWaveform...........................................................................................................................17
SelectUserWaveform.........................................................................................................................17
WaveformDownload...........................................................................................................................18
5. Firmware Upgrade..............................................................................................................18
6. TechnicalSupport...............................................................................................................19
7. Specifications......................................................................................................................19
Revision History..................................................................................................................................20
1. Getting Started
Introduction The FG085 isalowcostversatilefunction generatorcapableof
producing continuoussignal,frequencysweeping signal,servotest
signal,and userdefinedarbitrarysignals.Itwasdesigned asan
easy-to-usetoolforelectronichobbyists.The operation ofFG085
isextremelystraightforward. The following exampleswilllead
you step-by-step through some typicaluses.

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Frontviewof08501/08502
DataEntry Setting ofFG085 signalparameters isdone byfirst pressing one
ofthe parameterkeys(F/T,AMP,orOFS).The display ofthat
parameterwillbe cleared and an underline isshown,indicating
place fornewvalue tobe typed in. Ifatthe momentyou hit a
parameterkeythe cursorisnotcurrentlyatthatparameterjust
press the keyone moretimetomake the underline shown. Then
enternewvalue using the DIGITkeys.Completeentrybyhitting
one ofthe UNITSkeys.Ifan errorismade attyping pressing
[ESC]keywill do backspacetocorrectit.Ifno moredigitsleft
when [ESC]ispressed it will exit DataEntryand displaythe
originalvalue.
Acursorfocusedparametercan alsobeadjusted incrementallyby
tuning [ADJ]dial.
Examples 1 )To setoutputfrequencyto 5KHzpressthe following keys:
[F/T][5][KHz]
2)Tochangeoutputwaveformtosquarewave press [WF]until
SQR”isshown.
3)Tosetoutputamplitude to3Vpeak-to-peakpressthe
followingkeys:
[AMP][3][V]
4 )To setDC offsetto -2.5Vpress the followingkeys
[OFS][+/-][2][.][5][V]
2. FrontPanelFeatures

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1 )PowerSwitch Thepowerswitch turnsthe FG085 on andoff.
2 )ParameterKeys The parameterkeysselectthe parametertobe entered. Ifcursor
is notcurrentlyataparameterpressingthe parameterkeywill
firstmove cursorto thatparameter.
3 )Digit Keys The numerickeypad allowsfordirectentryofthe FG085’s
parameters.Tochange aparametervalue simplypress the
parameterkey(if cursorisnotcurrentlyatthe parameterpress the
parameterkeytwice)and then type anewvalue. Entriesare
terminated bythe UNITSkeys.Ifan errorismade attyping press
[ESC]keytocorrectit(back space).Ifno moredigitsleft when
[ESC]ispressed it will exitDataEntryand displaytheprevious
value.
The [+/-]keymaybe pressed atanytime during numeric entry.
4 )Unit Keys TheUNITkeysareused toterminatenumericentries.Notethat
the unitkeysrepresentdifferentunitatdifferentparameter
entry.
UnderCWmode pressingunit keyswithoutfirstenteringdigits
willdisplayincrementalstepsizes.[Hz]keydisplaysfrequency
step size. [KHz]keydisplaystime step size.
5 )WaveformKey Thiskeyselectsoutputwaveform.Repeated pressing ofthis
keywill go through allavailable waveforms.
6 )ESCkey Thiskeybackspace typed digitsand/orexitcurrentstate.
7 )ADJDial By[ADJ]dialuserscanincrementallyadjustafocused
parameterup and down. Todo thisfirstpressingaparameter
keytomovecursortheparametertobe changed and then turn
the dial.
UnderCWorSweep modepressingthe dialwilltoggleTrigger
functionon oroff.
AtServomode pressingthe dialwillenter SettingChange

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Frontviewof08501/08502
Boardviewof08503
state
8 )MODEKey ThiskeyselectsFG085’sworkingmodes.
9 )Frequency (Period)
Displayofcurrentoutputfrequencyorperiod.
10 )Waveform Displayofcurrentwaveformtype.
11 )DCOffset DisplayofcurrentoutputDCoffset.
12 )Amplitude Displayofcurrentoutputamplitude.
13 )Cursor Indication ofcurrentlyfocused parameter.Turning[ADJ]dial
will incrementallychange thisparameter.
When TriggerFunction ison the cursorchange to ‘*’.
14 FunctionOutput
(J4) Thisisthe frontoutputconnector. Itsoutputimpedance is50Ω.
3. Connectors

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1 )PowerInput(J1) ThisistheDC powersupplyinputconnector.Itscentercore
shouldbe connected tothe positivepoleofpowersupply.
FG085 isspecified for14V –16VDC.Thecurrentcapacityof
powersupplyshould be greaterthan 200mAaverage.
2 )Function Output
(J5) Thisisthe backoutputconnector. Itsoutputimpedance is50Ω.
3 )USB(J10) ThisprovidesaconnectiontoPCforwaveformdatadownload
and instrumentcontrol.
4 )AlternativeUSB
(J7) Thisconnectorallowswiringthe USBconnection tosocketat
enclosure.
5 )Contrast
Adjustment Thisisa trimmerforLCDcontrastadjustment.
6 )U5Programming
Port(J8) Thisistheprogrammingheaderforthemaincontroller
ATmega168 (U5).
Pin-outDescription
Pin#
Signal
Name I/O Function
1 MOSI I U5programming
2 +5V PWR
3 NC - Noconnection
4 - - Reserved
5 nRST I U5programming
6 - - Reserved
7 SCK I U5programming
8 GND PWR
9 MISO O U5programming
10 GND PWR
7)U6Programming
Port(J6) Thisisthe programmingheaderforthe DDScorecontroller
ATmega48 (U6)
Pin-outDescription
Pin#
Signal
Name I/O Function
1 MOSI I U6programming
2 +5V PWR
3 Sync O Syncoutput(sweepingmode)
4 - - Reserved
5 nRST I U6programming
6 TrigIn I Trigger input
7 SCK I U6programming
8 GND PWR
9 MISO O U6programming
10 GND PWR

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4. FG085 Operations
Power-on Pushdownthe powerswitch toturnon FG085. Itwillfirst
displaymodelname. Then manufacturer/vendornamefollows.
Afterdisplayingfirmwareversionstheunitenters normal
workingstate.
Output Theoutputamplitudedisplayisonlycorrectwhenload isin
highimpedance (much largerthan 50Ω).Ifload impedanceis
closeto50Ωtheoutputamplitudewillbelowerthen
displayed. Ifloadimpedanceis 50Ωtheoutputamplitude
will halfofthat displayed.
Mode Selection
FG085 can workinone offourdifferentmodes.Thesefour
modesare:
1) ContinuousWaveforms(CW)mode
2) FrequencySweepingmode
3) Servo Position mode
4) Servo Run mode
Pressing[Mode]button willdisplaythe mode selection menu.
Tuning[ADJ] will scroll throughthesemodes.The numberat
the lower-rightcornerindicatesmenu position. Pressing
[MODE]willselectthe mode displayed. Pressing[ESC]will
exitmode selection withoutchange.
ContinuousWaveform(CW)Mode
Inthismode the generatoroutputscontinuoussignalofselected waveforms.Signal
frequency, amplitude, and DCoffsetcan be independentlysetbyuser.
Screen Please referto Section 2 FrontPanelFeatures”.
WaveformSelection Waveformselection isdone bypressing[WF]key.

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Frequency Frequencyissetbyfirstpressing[F/T].The currentdisplay
willbeerased and an underlineisshown, allowing userto
enternewvalue.Newvalue isentered withdigit keysand
followedbyone oftheUnitkeys.Alternatively,frequencycan
be changed incrementallybyusingthe[ADJ] dialwhen it is
focused. Theincrementalstep sizecan be settoany number
you want(see below).
Frequencycan alsobe setinperiod (indicated byletter ‘T’).
Press[F/T]keywilltogglebetweenfrequencyand period entry
mode.
FrequencyRange
Inspiteofthatnolimitedrangeissetforfrequencyentryit
shouldbeawareofthattherearepracticalrangesforoutput
frequencyduetothelowresolution8-bit DAC and slow
samplerate(2.5Msps).Outoftheserangessignalqualitywill
degradedaslargerdistortionsand jittersappear. The acceptable
rangesdepend on actualapplications.ForFG085output
frequencywithinthe followingrangeisconsideredreasonably
good formostapplications.
Function Range
Sine
Square
Triangle
Ramp
Staircase
0 –200KHz
0 –10KHz
0 –10KHz
0 –10KHz
0 –10KHz
MaximumFrequency Error
Maximumfrequencyerrordependson sampleclockand phase
accumulatorsize. ForFG085 the phaseaccumulatorsizeis24
bits.Twosamplingclocks,2.5Mspsand 10Ksps,areused.
Sampleclockisautomaticallyselectedbased on frequency
settingasshownin the table below.
Frequency Sampling Clock MaximumError
> 40Hz 2.5Msps 0.1490 Hz
40Hz 10Ksps 0.0005960 Hz

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Amplitude Amplitude issetbyfirstpressing[AMP]key.Thecurrent
displaywill be erased andan underlineisshown, allowing
usertoenternewvalue.Newvalue isentered withDataEntry
keysand followedbyoneoftheUnitkeys.Alternatively,
amplitudecan bechangedincrementallybyusingtherotary
encoderwhen itisfocused.
Thedisplayed amplitude value ispeak-to-peakvalue.
The amplituderangeislimitedbythe DC offsetsettingsince
|Vac peak|+ |Vdc| ≤10 V(into High-Z).
D.C. Only
The outputofthe FG085can besettoaDClevelbyentering
amplitude of0V.When theamplitude issettozerothe A.C.
waveformwillbe completelyshutoff and the FG085 maybe used
asa DCvoltage source.
DCOffset DC offsetcan besetbyfirstpressing[OFS]key.Thecurrent
displaywill be erased andan underlineisshown, allowing
usertoenternewvalue.Newvalue isentered withDataEntry
keysand followedbyoneoftheUnitkeys.Alternatively,
offsetcan be changed incrementallybytuning[ADJ]when it
isfocused.
In general, the DCoffsetmayrange between ±5V, butit islimited
such that|Vacpeak|+|Vdc| ≤10 V(intoHigh-Z),or|Vac peak |+
|Vdc| ≤10 V(intoHIGH-Z).
Incremental
Adjustment
FG085’soutputfrequency,amplitude, and DC offsetcan be
changed incrementallyup and down byusing[ADJ]dial.Todo
thisfirstmovecursortotheparameteryou wanttochangeby
pressingaparameterkey andthen turnthe rotaryencoder
clock-wiseforincrementand counter-clock-wisefor
decrement.
Tip
Incrementalstep sizecanbe settoanyvalue. Todo this
directlyenterthe step size you wantand followby [Hz]or[ms]
button. [Hz]button setsstep sizeforfrequencyadjustment.
[ms]button setsstepsizefortimeadjustment.Press [Hz]or
[ms]withoutdigitswilldisplaycurrentfrequencyortimestep
size.
DutyCycle
(forsquarewaveform)
Dutycyclecanbe settovalue between 0%and 100%. Pressing
[.](the decimalpointkey)will displaycurrentdutycycle.
Press[.]keyagainthe displaywillbe erased andan underline
willshow,allowingusertoenternewvalue. Pressing anyof
the unit keysterminatesthe entry.Pressing[ESC]returnsto
normalCWmode display.
Notethatdutycycleonlytakeseffectforsquarewaveform.
Theacceptable value rangeis0 –100%with resolutionof1%.

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Trigger Function Thetriggerfunction allowsusertocontrolthegeneratoroutput
byan externalsignal.WhentheexternalsignalisHIGHoutput
signalisstopped. Assoonasthetriggersignalchangesto
LOWoutputsignalresumes(see screen capture below).
TheexternalsignalmustbeTTLlevelcompatibleandapplied
to pin 6 ofJ6.
The triggerfunction can beturned on/offbypressing [ADJ]
dial.Whenitisonthecursor(normally ‘>’)willchangeto ‘*’
asindicator.
Theinitialphase ofoutputsignalateach triggerisconstant.
Notethatthetriggerinputispulled toHIGH internally.There
willbeno outputwhen theterminalisleftopen. Thisfeature
allowsusinga switch astriggersource.
Triggerwaveform
FrequencySweepingMode
Inthismode FG085 generatefrequencysweeping signals.The sweeping range andrateas
well assignalamplitude and DCoffsetare all independentlysetbyuser.
Screen
Turning[ADJ] orpressingdigit buttons[1],[2],[3],and [4]
will haveStartFreq, Stop Freq, Sweep Time, and TimeStep
Size displayed respectively.

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WaveformSelection Waveformselection isdone bypressing[WF]key.
Normalsweeping
Bi-directionalsweeping