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Manual - Test Equipment Depot

1. Pulse nL Noise AWM Arb selects waveforms Key CHA Output Trigger CHB Output Trigger Turns on or off the signal output of channel A amp channel B and the trigger output of channel A amp channel B Key Utility sets the system parameters and exits remote control 1 4 2 Soft Key There are five soft keys at the right side of LCD display They are used to select the various options under each function 1 4 3 Numeric Keypad Key 0 1 2 3 4 5 6 7 8 9 for numeric input Key decimal point Key negative sign 1 4 4 Unit Soft Key There are five blank keys at the bottom side of LCD display The definitions of these soft keys change according to the characteristics of data The input value has to be validated by pressing the unit soft key at the end of data input 1 4 5 Directional Key Key lt d and P cursor keys used to add or subtract the digit on the cursor when tuning the rotary knob Key A and F used to increase or decrease the frequency or amplitude of channel A at the specified step 1 5 Fundamental Operation This section introduces the fundamental operations on the general requirements through some examples See Chapter 3 for more information if you have complex problems or need the complicated operations 1 5 1 Function of Channel A Press key Channel to select CHA Alone function Set the frequency of channel A set frequency at 3 5kHz Select
2. sequentially stored in the waveform memory by the address of x DDS uses the phase accumulating technique to control the address of the waveform memory In every single sampling period a phase increment is added to the current content of the phase accumulator The output frequency of DDS can be modified by changing this phase increment The digitized waveform data is read from the waveform memory addressed by the phase accumulator and converted into an analog voltage through D A converter and amplifier circuitry Because the waveform data are the interval samples the output of DDS is a stepwise sine wave Thus the output waveform from DDS has to be filtered out the high harmonic components by a low pass filter The high accurate reference regulator in D A converter assures the amplitude precision and stability of the output waveform The amplitude controller is a D A converter According to the preset amplitude value this converter generates a corresponding analog voltage which multiplies with the output signal and produces a final output signal whose amplitude is equal to the preset value The offset controller is also a D A converter According to the preset offset value this converter generates a corresponding analog voltage which adds with the output signal and produces a final output signal whose offset is equal to the preset value The output signal is output at the channel A 2 3 Principle of Operation and Control The MCU controls keypad
3. 1 1 Preparation 1 1 1 Check the Function Generator and Accessories Check the function generator and accessory parts and verify all items in the good shape If the box is broken please keep the box until the function generator passes function test 1 1 2 Connect the Function Generator to Power Only under the conditions below users can connect power cable and turn on the power switch Voltage AC220V 1 10 AC110V 1 10 Pay attention to the position of voltage selection switch Frequency 50Hz 1 5 Watts lt 45VA Temperature 0 40 C Humidity lt 80 Plug the power cord into an 110V or 220 V power outlet with ground connection and turn on the function generator The function generator starts to initialize display the instrument name load the default parameters display menu of Channel A frequency start channel A and B output signal After initialization the function generator is in the normal working mode WARNING For protection from electrical shock the three hole power cord with protective earth ground has to be used 1 2 Front Panel and Rear Panel Front Panel Hn Test Equipment Depot 800 517 8431 99 Washington Street Melrose MA 02176 TestEquipmentDepot com 1 Power switch 2 LCD display 3 Unit soft key 4 Software option 5 Function key and Numeric keypad 6 Direction key 7 Rotary knob 8 Channel A trigger output 9 Channel B trigger output Rear Panel WARNING HAZARDOUS VOLTAGE IN
4. TTL_A signal is used as the trigger signal The burst frequency actually is the TTL_A frequency The burst frequency is determined by 19 the values of the Channel A frequency and the burst count The multiple of channel A signal period value and burst count number is the time needed for a set of burst Burst period value should be bigger than the interval time so as to make sure of a suitable interval time between each set of burst Otherwise all sets of burst will be output continuously and cannot be a burst signal 3 10 5 Set the Single Burst Mode Press the soft key corresponding to TTL_A Trig twice to step down to Single to enter single burst mode The function generator turns off the continuous burst mode and signal output In the single burst mode press key CHA Output Trigger once the burst process executes once and the function generator outputs one burst waveform according to the preset value of the burst count If the burst count is set to 1 users can output the single burst manually 3 10 6 Set TTL A Burst Select TTL_A Burst by the corresponding soft key At the rise edge of every TTL_A signal the burst process executes once according to the preset burst count number and outputs a set of preset numbers of burst waveform The burst process is operating continuously 3 10 7 Set External Burst Press the soft key corresponding to TTL_A Burst to step down to EXT Burst to enter external burst m
5. Frequency by the corresponding soft key then press keys 3 5 and the soft key corresponding to kHz Adjust the frequency of channel A press 4 or P gt keys to move the triangle shape cursor left or right and rotate the knob left or right to decrease or increase the digits continuously for the coarse or fine adjustment of frequency Apply the same for adjustments of other parameters Set period of channel A set a period of 25ms Into the frequency menu select Period by the corresponding soft key then press keys 2 5 and the soft key corresponding to ms Set amplitude of channel A set amplitude peak value at 3 2Vpp Into the frequency menu select Amplitude by the corresponding soft key then press keys 3 2 and the soft key corresponding to Vpp Set amplitude of channel A set amplitude value at 1 5 Vrms Select Amplitude by the corresponding soft key then press keys 1 5 and the soft key corresponding to Vrms Set offset of channel A set DC offset at 1 Vdc Select Offset by the corresponding soft key then press keys 1 and the soft key corresponding to Vdc Select waveform of channel A select square waveform Press key Square m Set duty ratio of channel A set pulse duty ratio at 25 Into the impedance menu select Duty by the corresponding soft key then press the soft key corresponding to duty ratio next press keys 2 5 and the soft key corresponding t
6. Frequency 1kHz RS232 mode 88CHB BWAVE 2 No 88CHB BTRIG 1 kHz Example 3 Channel A Single Output Pulse wave Duty cycles 25 RS232 mode 88CHA ADUTY 25 Example 4 Frequency Sweep output Start frequency 1kHz RS232 mode 88FSWP STARF 1 kHz Example 5 FSK output Carrier frequency 25kHz RS232 mode 88FSK CARRF 25 kHz Example 6 Query channel A frequency operation mode RS232 mode 88CHA AFREQ Example 7 Return to the control mode and recover keypad operation RS232 mode 88LOCAL 27 Chapter 5 Frequency Counter amp RS232 This chapter introduces the function generator accessories which are not included in the standard 5 1 Frequency Counter If users choose to purchase the frequency counter the frequency count board will be installed in the instrument The input connector is the Count in connector on the rear panel The detail instruction is in the section 3 13 5 2 RS232 Ifusers choose to purchase RS232 interface user can remote control the instrument from a computer 28 Chapter 6 Technical Specifications 6 1 Output Characteristics of Channel A 6 1 1 Waveform Characteristics Waveform type 32 waveforms including Sine Square Triangle Pulse etc Waveform length 1024 points Sampling rate 100MSa S Waveform amplitude resolution 8bits Sinusoidal harmonic rejection gt 40dBc lt 1MHz gt 35dBc 1MHz 20MHz Sine wave total distortion lt 1 20Hz 200kHz Square rise fall edge time lt 35ns Overshoot
7. PSK O ds daa 3 10 Burst Output of Channel A 3 10 1 Set the Carrier Frequency sese 3 10 2 Set MECA Ad 3 10 3 Set the Burst Count TTT 3 10 4 Set the Burst Frequency sese 3 10 5 Set the Smele Burst Mode aa Si LOO Sets TLL cA Blind 3 10 7 Set External S ai 3 11 Burst Outp t of Chatinel Boot ci etl teen tevin ntl teat tein eles 3112 TVs Outputixicssck oe hie elcid id Merete Qeseee at E 3 12 1 Set the TTL A Frequency svc sosic5 c5c5 ack cenit Salad i ictacbes locks adage cies lecdieds Jit sdeitestsens ia a suds 3 12 2 Set the TTL A Duty Cycle ssnin ussi rai reisai iseda ieran r Ea isa ios 3 12 3 Set the TTL_B Ts LT VI 3 12 4 Set the TTL B Duty Cycle rico ooo 21 3 13 Measure External SA 21 3 13 1 Self Check and Demonstration sss esse eee eee eee 21 3 13 2 Meas re External Frequentes 21 AS the Gate Tinie secs e a 21 NA O OOO 22 E Store Parameters nidad 22 3 14 2 Recall Parameters as 22 3 14 3 Remote Address wiicccccacscccetsseacceasscascotedenecotescnecoaedenedenedanedetodenedetedcnedatedanedatedanedatedanedateshecndedatoe 22 ER RS HHH 22 SAS CHOOSE A A O 22 Chapter 4 Programmable Interface eee ee 23 4 1 Interface Application oooooonnonononcnonononononononononono nono nono nono nono nono ES 23 AD RIS 232s A TTT 23 4 2 1 Interface Voltage Level 23 4 2 2 Transmission Formatas zsie e deisel chive dd dete Rae aes Wht ni 23 42 3 Transmission Rate ii lilas 23 4
8. SIDE DO NOT REMOVE THE COVER UNLESS BY SPECIFIED PERSONNEL WARNING MAINTAIN GROUND TO AVOID ELECTRIC SHOCK fo ST AC 110 100 120V 60Hz Fuse 2A AC 220 200 240V 50Hz Fuse 1A 1 A TTL B TTL output BNC 2 Modulation External signal input BNC 3 Power connector with fuse 4 AC110V 220V power selection switch 5 RS232 connector 1 3 Description of LCD Display CHA 00Sine CHB 00 Sine 1000 00Hz 1000 00Hz 2 000Vpp 500 _ 2 000Vpp 500 Frequency Amplitude 0 000Vdc 50 0 0 Offset gt CHA Frequency 100f 00Hz Waveform gt CHA Amplitude CHA Offset 2 000Vpp 0 000Vdc Channel A waveform display the waveform of channel A and preset parameter is displayed at the upper left portion Channel B waveform display the waveform of channel B and preset parameters are displayed at the upper middle portion Function menu The first line on the right of the LCD displays the function menu Option menu The second to the sixth lines display the option menu Parameter menu Three of the waveform parameters of channel A are displayed at the middle of the lower left portion Unit menu The bottom line displays the unit menu 1 4 Key Description On the front panel there are 38 keys which are divided into five categories 1 4 1 Function Key Key Freq Sweep MOD BURST SK TTL selects the ten functions of the instrument Key COUNT selects the function of frequency counter Key Sine ny Square m Ramp
9. a unit key to validate the input data If the input data has error there are two ways to correct it If the destination side of output signal can receive the wrong signal press any unit key to terminate the pervious operation Input the correct data and press the unit key to validate the input If the destination side of output signal can not receive the wrong signal the wrong input is not validated because of no any wrong signal at the output In this case reselect the operation input correct data and press the unit key to validate the input Although there are a variety of combinations of the decimal point and the unit key for data input the instrument always displays the input data in a fixed format For example input either 1 5kHz or 1500Hz after validation the instrument will display as 1500 00Hz 10 3 1 4 Knob Adjustment In some applications it is required to adjust the output signal continuously The rotary knob is in use here When a parameter is selected the color of this parameter changes to yellow and the color of one digit in this parameter changes to yellow too Actually this digit is located on the cursor position Press key 41 or gt to move the cursor left or right Rotate the knob to the right to continuously increase the digit on the cursor by one and make the carry to a higher unit position Rotate the knob to the left to continuously decrease the digit on the cursor by one and make the carry to a lower unit
10. continuous variation of the output signal in full amplitude range But in range of OdB if the signal amplitude value is too small there will be higher waveform distortion and the signal amp noise ratio can not be so good 3 2 5 Output Load The default amplitude value is calibrated when the output is open circuit The real voltage on the output load is the default amplitude multiplying the dividing ratio of the load and the output load The output resistance of the instrument is about 50Q When the load resistance is big enough and the voltage dividing ratio is close to 1 the 12 loss on the output load resistance can be ignored The voltage on the load is close to default amplitude value When the load resistance is too small the loss on the output load is significant and can not be ignored The voltage on the load is not same as the default amplitude value Please pay attention to this point The output of channel A has the over voltage and over current protections The instrument can not be damaged if the output is short only few minutes or the transient inverse voltage less than 30V However this kind of operation should avoid in case of potential damage to the instrument 3 2 6 Amplitude Flatness If the output frequency is lower than 1MHz the amplitude and frequency characteristics of the output signal are very flat If the output frequency is over 10MHz due to the characteristics of the output amplitude and load matching the amplit
11. dial In the ASK mode the channel A signal is the carrier signal The first amplitude of channel A signal is the carrier amplitude 3 8 2 Set the Hop Amplitude Select Hop Amp by the corresponding soft key The hop amplitude value changes to yellow Input a new hop amplitude here via numeric keypad or rotary dial The hop amplitude is the second amplitude of the channel A 3 8 3 Set the Interval Time Select Interval by the corresponding soft key The interval time value changes to yellow Input a new interval time value here via numeric keypad or rotary dial 3 9 Phase Shift Keying PSK Press key SK to step down to CHA PSK The function generator outputs the PSK signal on the CHA Output The phase of output signal is the alternative variation of the reference phase and the hop phase The alternative time of these two phases can be set at the desired value 3 9 1 Set the Hop Phase Select Hop Phase by the corresponding soft key The hop phase value changes to yellow Input a new hop phase value here via numeric keypad or rotary dial The hop phase here is the second hop phase value of channel A signal The basic phase value is the phase value set in channel A setup 18 3 9 2 Set the Interval Time Select Interval by the corresponding soft key The interval time value changes to yellow Input a new interval time value here via numeric keypad or rotary dial 3 9 3 PSK Observation Due to the phase varia
12. format can only be used at the channel A or channel B frequency mode and the waveform selected as sine For other operations and waveforms only peak to peak format can be used 3 2 4 Amplitude Attenuation Press the corresponding Offset soft key twice to step down to Attenuator After instrument power on or reset the attenuation is default in AUTO mode In AUTO mode the instrument automatically selects suitable attenuation ratio according to preset amplitude values When the output amplitude is at 2V 0 2V or 0 02V the instrument switches between attenuation ratios In this situation the instrument generates a waveform of high amplitude resolution high signal amp noise ratio and low distortion regardless of signal amplitude values However during attenuation ratio switch there is instant hopping in the output signal which is not allowed in some practices That is why the instrument has preset with fixed attenuation mode Select Attenuator by the corresponding soft key An attenuation data can be input here by numeric keypad or rotary dial There are five ranges of attenuation 0dB 20dB 40dB 60dB and AUTO which can be input by numeric key 1 2 3 4 and 0 respectively The attenuation mode can also be selected by rotary dial One step in rotary dial tuning goes to one range If a fixed attenuation mode is selected the attenuation is fixed and does not change according to amplitude value changes which make
13. function generator outputs the desired modulated signal 3 6 5 External Modulation Source The frequency modulation can use the external modulation signal There is a Modulation In connector on the rear panel to import external modulation signal The external modulation signal frequency should be compatible to the frequency of carrier signal The amplitude of external modulation signal should be adjusted according to the frequency deviation The bigger the external signal the bigger the frequency deviation In the external modulation mode the frequency depth deviation should be set to 0 and turn off the internal modulation signal Otherwise it will affect the external modulation process Similarly in the internal mode the frequency depth deviation should be set and the external signal connection should be disconnected Otherwise the internal modulation will be affected 3 7 Frequency Shift Keying FSK In the digital communication and remote measurement systems the transmission of the digital signal uses the Frequency Shift Keying FSK or Phase Shift Keying PSK method to encode the frequency or phase of the carrier signal At the receiving station the received signal is decoded and recovered to the original digital signal Press key SK and select CHA FSK option The function generator outputs the FSK signal on the CHA Output The upper left portion of the LCD displays the FSK waveform The frequency of the output signal i
14. lt 10 Square wave duty cycle 1 99 6 1 2 Frequency Characteristics Frequency range Sine 40mHz Max frequency MHz Other waveforms 40mHz 1MHz Frequency resolution 40mHz Frequency accuracy 5x 10 40mHz Frequency stability 5x 10 3 hours 6 1 3 Amplitude Characteristics Amplitude range 2mVpp 20Vpp 40mHz 10MHz high impedance 2mVpp 15Vpp 10MHz 15MHz high impedance 2mVpp 8Vpp 15MHz 20MHz high impedance Resolution 20mVpp amplitude gt 2Vpp 2mVpp amplitude lt 2Vpp Accuracy 1 2mVrms high resolution true RMS frequency at 1kHz Stability 0 5 3 hours Flatness 5 frequency lt 10MHz 10 frequency gt 10MHz Output impedance 50Q 6 1 4 DC Offset Characteristics Offset range 10V high impedance attenuation 0dB Resolution 20mVdc Accuracy 1 20mVdc 6 1 5 Sweep Characteristics Linear sweep on frequency or amplitude Sweep range free to set start point and stop point Sweep step higher than any value of resolution Sweep rate 10ms 60s step Sweep mode UP DOWN UP AND DOWN Manual sweep step time 6 1 6 Modulation Characteristics Carrier signal channel A signal Modulation signal channel B signal or external signal Modulation depth 0 20 29 6 1 7 Shift Keying Characteristics FSK free to set carrier frequency and hop frequency ASK free to set carrier amplitude and hop amplitude PSK hop phase 0 360 Max resolution 1 Alternative rate 10ms
15. position When using the knob to modify a specified data the modified data is valid instantaneously without pressing the unit key Move the cursor left to make a coarse adjustment and move to the right to make a fine adjustment 3 1 5 Frequency and Amplitude Step Input In applications it is very common to input a set of data or several sets of data with the same frequency or amplitude interval It is complicated and time consuming to input this kind of data by repeatedly pressing the numeric keypad and unit key However it is very convenient to use the step input method Set the frequency interval as the step frequency value every press on key A makes the frequency increase by one step value every press on key W makes the frequency decrease by one step value The modified data is validated automatically without pressing the unit key For example generate a series of frequency with an interval of 12 5 kHz press the keys sequentially as following Press the corresponding soft key to Step Frequency Press keys 1 2 and 5 and the soft key corresponding to kHz Into CHA menu press the soft key corresponding to Frequency Press keys A to increase the frequency by 12 5k Hz or press key W to decrease the frequency by 12 5kHz Repeat this operation a series of waveform with equal interval frequency difference can be generated The same procedure can be used for the amplitude operation This method can only be use
16. the 8x16 size text The other is the parameter value displayed in a variety of colors These setups make the LCD display more beautiful and easier to recognize The parameter display is divided into the five areas below Frequency area display the frequency value or period value Amplitude area display the output amplitude Because of the frequently used of frequency and amplitude parameters they are displayed in a larger font size to make them eye catching Offset and Other Parameters area display all parameters except the two important parameters The data units are shown on the bottom line of the LCD display The units change according to the data characteristic The input data have to be validated by pressing the corresponding one of the five blank soft keys parameter of Channel A area display the current waveform function and the other parameters of the channel A parameter of Channel B area display the current waveform function and the other parameters of the channel B 3 1 3 Numeric Keypad Input If a parameter is selected the color of this parameter changes to yellow which means this parameter can be modified There are ten numeric keys for data input The input method is the shift input from left to right The data can have one decimal point If one data input has more than one decimal point only the first one is valid In the offset mode the negative sign can be input After input a value press
17. 0 kHz Set start frequency set start frequency at 10kHz Select Start Freq by the corresponding soft key then press key 1 0 kHz Set step frequency set step frequency at 200Hz Select Step Freq by the corresponding soft key then press key 2 0 0 Hz Set sweep mode set sweep mode at down sweep Select Down Swe by the corresponding soft key Set interval time set interval time at 25ms Select Interval by the corresponding soft key then press key 2 5 ms Set manual sweep set the sweep at manual mode Select Manual Sweep by the corresponding soft key This operation ceases the continuous sweep mode Press key CHA Output Trigger for one time the frequency of channel A will step up or down by one step 1 5 4 Amplitude Sweep Press key Sweep to select A SweepA Apply the same setting procedure as described in section 1 5 3 1 5 5 Frequency Modulation FM Press key MOD to select CHA FM Set carrier frequency set carrier frequency at 100kHz Select Carrier Freq by the corresponding soft key then press keys 1 0 0 and the key corresponding to kHz Set carrier waveform amplitude set carrier amplitude at 2Vpp Select Carrier AMP by the corresponding soft key then press keys 2 and the key corresponding to Vpp Set frequency modulation set frequency modulation at 10kHz Select MOD Freq by the corresponding soft key then press key 1 0 and the key corresp
18. 0 240 English Chinese simplified Chinese traditional 6 4 5 Dimension and Weight 415mmx295mmx195mm Weight 3 5kg 6 4 6 Manufacturing Technology Surface Mount Technology Integrated Circuit High reliability and stability 6 5 Frequency Counter Characteristics 6 5 1 Frequency Counter Testing frequency range 1Hz 100MHz or 1Hz 150MHz Input signal amplitude 100mVpp 20Vpp 31 Test Equipment Depot 800 517 8431 99 Washington Street Melrose MA 02176 TestEquipmentDepot com
19. 2 4 Interface Comet iii lia 23 4 2 5 System CONSUME dll 24 ADO EMVITOHM O a da 24 4 2 7 Addr ss Information ies 24 4 2 8 Data Information iii diia 24 43 Remote Command oenar a a EEEE EEEE EE AAE AEAEE 24 AL Command Stina s oea enna aa Ea EEE AE EEE EEEE EE EE 24 43 2 Character RM dan 26 4 3 3 Separate Character sese 26 4 3 4 Question Mark sss 26 AO Data Stine A AA RN ads 26 4 3 6 Control Capability cian iii 26 4 3 7 Serial Port Controla iii ii 26 ESOO Operation tios 26 AAA pplication OA A A tii 26 4 4 1 Enter the Programmable Mode sss 27 4 4 2 Tips for Writing a Program sse eee esse eee eee 27 4 4 3 Application Example ooocccoocnnonononononononononononcno nono ncnn nono nono nono ncnnncnnn cnn nnnn nono nr nn nc nn nn an nr nan r non nnn rca ninos 27 Chapter 5 Frequency Counter amp RS232 ron tans e ene eases ease eneneeaeneenegens 28 Sy L Frequency Colt a a 28 KE NN AS eer er Pe eeepc ye ter Tere e e ee COE o e O e lc e o ed 28 Chapter 6 Technical Specifications ooooocooccononnonconcnncononnn non nno nc EEE EEE EEE EE EEE EE EEE EEE EE EEE EEE EEE EES 29 VII Chapter 1 Quick Starting This chapter describes the front and rear panels of the DDS function generator The brief introduction of the function generator helps you get familiar with the fundamental operations and functions The main contents in this chapter are as following
20. 60s 6 1 8 Burst Characteristics Carrier signal channel A signal Trigger signal TTL_A signal Burst count 1 65000 cycles Burst mode Internal TTL External Single 6 2 Output Characteristics of Channel B 6 2 1 Waveform Characteristics Waveform type 32 waveforms including Sine Square Triangle Pulse etc Waveform length 1024 points Sampling rate 12 5MSa S Waveform amplitude resolution 8bits Square duty cycle 1 99 6 2 2 Frequency Characteristics Frequency range Sine 10mHz 1MHz Other waveforms 10mHz 100kHz Resolution 10mHz Accuracy 1x10 10mHz 6 2 3 Amplitude Characteristics Amplitude range 50mVpp 20Vpp high impedance Resolution 20mVpp Output impedance 50Q 6 2 4 Burst Characteristics Carrier single channel B signal Trigger signal TTL_B signal Burst count 1 65000 cycles Burst mode Internal TTL External Single 6 3 TTL Output Characteristics 6 3 1 Waveform Characteristics Square rise fall time lt 20ns 6 3 2 Frequency Characteristics 40mHz 1MHz 6 3 3 Amplitude Characteristics TTL CMOS compatible low lt 0 3V high gt 4V 30 6 4 Common Characteristics 6 4 1 Power Source Voltage AC220V 110 AC110V 110 Pay attention to the voltage selection on rear panel Frequency 50Hz 1 5 Power lt 45VA 6 4 2 Environment Temperature 0 40 Humidity lt 80 6 4 3 Operation Characteristics Keypad operation and rotary knob operation 6 4 4 Display TFT LCD display 32
21. B waveform BWAVE Data Digit Negative Sign The Table of the Data Command String Data String 0123456789 Decimal Point 25 String ABURST BBURST FSK ASK PSK TTL RS232 String HOPA HOPF HOPP EXTTR EXT RESET PHASE VRMS LANG CARRA CARRF STROBE STOPA STOPF AUTO STORE SWITCH The Table of the Unit Command Unit String Unit String Frequency MHz kHz Hz mHz Phase DEG Peak to peak Value Vpp mVpp Attenuation dB Time s ms Index No Harmonic wave TIME Percentage Burst count CYCL DC offset Vdc mVde RMS Vrms mVrms 4 3 2 Character Return The length of a remote command cannot exceed 60 characters Every string is ended with a Chr 10 4 3 3 Separate Character The separate character has to be placed between the function and option strings the option and data strings the data and unit strings and the function string and question mark 4 3 4 Question Mark To add the question mark before the option string will be back the corresponding value and unit If no unit only back to the value 4 3 5 Data String The maximum length of the data string is 10 characters 4 3 6 Control Capability The remote commands can control all instrument functionalities 4 3 7 Serial Port Control In the serial port control mode first user must send the instrument s address and then select the corresponding instrument next send the remote commands 4 3 8 Online Operation First send the interface select comman
22. Channel A 3 210 Set the Duty Cycle of Channel As ds e e 3 2 11 Set the Phase of Channel A 3 3 Setup ot Channel Bid ai ds tite ee tl cta on do e tds cc es 3 3 1 Set the Frequency of Channel B sees 3 32 06 tHe Amplitude of Channel Bi a 3 3 3 Select the Waveform of Channel B 3 3 4 Set the Harmonics of Channel B Sid FEQUENCY SWEEP s ach A ceecade dro olbgeaseecaeeate dci daa EE EE 342 Set the Step FrequenCy r eas e eaen rn o nae a ae Erene e lleida Weeds 3413 Select Sweep Moden iaa A E ASE TTT KAMPIS SVE Dae e e cet dk ed e ado ee AD EA O tLe ADE AOL O Ae a ed 3 6 Frequency Modulation FM TTT 3 61 Set the Carrier Frequentes 3 6 2 Set the Modulation Frequency sss 3 6 3 Set the Frequency Deviation ccceccceceeseeseessceseeseeseesececeeseesecseceeesessecsesceeseeaeseeeeeeeseeaeeneeeneeaes 3 6 4 Set the Modulation Waveform sees 3 6 5 External Modulation Source sees 3 7 Frequency Shift Keying PSK ss ssss seene erren JAA oA Me Carer FAUNO daa 3 9 2 Setthe Hop Frequent oios eeno i EA A E E E EEA S E S Interval TIME annae E iA A eE EA Ea O 3 8 Amplitude Shift Keying ASK eee 3 8 1 Set the Carrier Amplitude ooooonconnononocononononononononononononono nono nono nono nono non EREKET REEERE TENIS ERENER ninos 38 2 the Hop Amplitude TTT I I es 3 8 3 Set the Interval TM iii did 3 9 Phase Shift Keying PSK conocia rd 3 9 le Set he Top Plasmas e a E teases ia dee reese eine eed 3 92 Set the Intetval Tames A E AS 3 9 3
23. Count In terminal on the rear panel Select External Freq by the corresponding soft key The test result displayed is the current channel A frequency value Since channel A frequency synthesizer uses the same clock with frequency tester the test result does not have the affect of crystal error Therefore the test result is highly accurate 3 13 2 Measure External Frequency Select EXT Freq by the corresponding soft key Input the external frequency from the Count In terminal on the rear panel The LCD displays the testing external frequency value The testing external signal can be period signal of the arbitrary waveform The signal amplitude peak to peak value should be 100mVpp 20Vpp Due to the affect of crystal error and trigger error the accuracy and stability may not be as good as those in self check 3 13 3 Set the Gate Time Select Strobe Time by the corresponding soft key The gate time changes to yellow Input a new gate time data here by numeric keypad or rotary dial During frequency measurement the tested signal must be continuous However the measurement is intermittent With the preset gate time as a cycle the instrument makes sampling of the tested signal analyzes the testing data and refreshes display The instrument usually adopts average periodical measurement The longer gate time the more cycle numbers to be collected from the testing signal the more stable the average value the more valid digits to
24. Hoang 5 LS 7 Burst ount of Chant Bi cutee scbeasoes cede iu saber en ceianunaeawacdetenneeteeeten eens 6 1 5 S ESKE Modulation ESO iii tibia 6 1 5 9 Amplitude Shift Keying ASK asses eee 6 1 5 10 Phase Shift Keying HDR RT inisee an cate TRT ah Ta oO ATT RT ETT a RO aater 6 I HR O OO 7 Chapter 2 Principle of the Function Generator ee 8 2 1 Principle Diarra dida 8 2 2 Principle of Direct Digital Synthesis sse eee eee 8 2 3 Principle of Operation a E 0s csecesecess E E ai eases eee ees es ee ei 9 Chapter 3 Operation Instructions 0 cece cece ee eee nen eee EEE EEE EEE EEE EEE EEE EE EEE EEE EEE EEE EEE EEE 10 3 1 Operation Common Rules sss 10 3 1 1 Ment Selection cs il oda 10 3112 Parameter Display iii da 10 3 1 3 Numerie Keypadinput is 2 aan eet a e cd do eos da 10 ALARMAS is 11 3 1 5 Frequency and Amplitude Step Inputs sese 11 A SA E E E teeing 11 3 2 Setup of CIAT LAS iar aen e AE A EEA EI 11 3 2 1 Set the Frequency of Channel A 11 3 2 2 Set the Period of Channel Aeee En ereo ean iee 11 Jaa Setthe Amplitude oft Chanie lA n a A EA toy 12 3 2 4 Amplitude Attenuation sss sees 12 3 2 5 Output Load RO 12 3 2 6 Amplitude Flatness aA a E E E AEAEE 13 3 2 7 Set the Offset of Channel A ccc csccccdescescessesceusdsgseecudedevsvadessnecsdedevevedesshsstdedevedetasstevadateseissceetss 3 2 8 DC Voltage Outp ti enisinia did 3 2 9 Select the Waveform of
25. In some applications it is required to frequently use a set of certain parameters such as frequency amplitude offset waveform etc It is very easy and convenient to store and recall these frequently used parameter settings After input a set of parameters press soft key SYS input the memory index number by numeric keypad press the corresponding soft key of No to store this set of parameter setting into the corresponding memory Apply the same storage procedure to store up to 39 sets of parameter settings The parameter memory uses a non volatile memory which can store the settings even the instrument is power off If you need to use the stored parameter later select Recall by the corresponding soft key input the recall index number and press the soft key corresponding to No The stored parameter setting is recalled If select Recall then press key 0 and the soft key corresponding to No to recall the default parameter setting 3 14 3 Remote Address Select Address by the corresponding soft key The remote address changes to yellow The remote address can be entered by numeric keypad or rotary dial After power on the instrument remote address is default as 88 If the instrument is connected to other equipments with RS232 interface to make an auto testing system each equipment in the system should have a different remote address for PC recognition 3 14 4 Beeper Select Beep On by the corresponding soft
26. TTL to enable the TTL function The upper left portion of the LCD displays TTL and there is TTL signal output at the TTL_A and TTL B terminals on the rear panel 20 3 12 1 Set the TTL_A Frequency Select TTL_A Freq by the corresponding soft key The LCD displays TTL_A frequency value A new TTL_A frequency value van he set here via numeric keypad or rotary dial 3 12 2 Set the TTL A Duty Cycle Press soft key corresponding to TTL_A Duty The LCD displays TTL_A duty ratio value A new duty ratio value can he set here via numeric keypad or rotary dial 3 12 3 Set the TTL_B Frequency Select TTL_B Freq by the corresponding soft key The LCD displays TTL_B frequency value A new TTL B frequency value can he set here via numeric keypad or rotary dial 3 12 4 Set the TTL B Duty Cycle Select TTL_B Duty by the corresponding soft key The LCD displays TTL_B duty ratio A new TTL_B duty ratio value can he set here via numeric keypad or rotary dial 3 13 Measure External Frequency Press key COUNT to select EXT Freq option by the corresponding soft key The LCD display shows the external measurement interface In this mode the instrument is a frequency meter and measures the frequency value of the external signal 3 13 1 Self Check and Demonstration The instrument is capable of using internal waveform to carry out self check and present demonstration Use a test cable to connect the CHA terminal with the
27. Test Equipment all SW ngton Street Depot Melrose MA 02176 Phon e 781 665 1400 1 800 517 8431 Toll Free 1 800 517 8431 q DDS Function Generator DFG 1000 series 5MHz 20MHz Operation Manual V1 0 E Z aa S a L UY a Q an O Z as aa CE Use of Operation Manual Please read through and understand this Operation Manual before operating the product After reading always keep the manual nearby so that you may refer to it as needed When moving the product to another location be sure to bring the manual as well Calibration notification We notify that the instruments included in this manual are in compliance with the features and specifications as stated in this manual Before shipment the instrument has been calibrated in factory The calibration procedures and standards are compliant to the national regulations and standards for electronic calibration Warranty We guarantee that the instrument has been passed strict quality check We warrant our instrument s mainframe and accessories in materials within the warranty period of one year We guarantee the free replacement or repair of products which are approved defective To get repair service please contact with your nearest sales and service office We do not provide any other warranty items except the one being provided by this summary and the warranty statement The warranty items include but not being subjected to the hinted guarantee items related to tradabl
28. alf round 26 Ne bipulse 03 Up ramp 11 All sine 19 Tangent OF Trapezia 04 Down ramp 12 Half sine 20 Sin x x 28 Cosine 05 Pos pulse 13 Limit sine 21 Noise 29 Bidir SCR 06 Neg pulse 14 Gate sine 22 Duty 10 30 Cardiogram 07 Tri pulse 15 Squar root 23 Duty 90 31 Earthquake 3 2 10 Set the Duty Cycle of Channel A For the convenience of application the duty cycle value can be input via numeric keypad or rotary dial When the current duty cycle value is changed to yellow the output duty cycle is the square wave of the preset duty cycle The pulse duty cycle can be set at any value between 1 99 The duty cycle can be displayed only when the pulse wave is selected 3 2 11 Set the Phase of Channel A Press the corresponding soft key to step down to Phase The phase value can be set at any value between 0 360 via numeric keypad or rotary dial When the frequency is at low value the phase has a high resolution For example the frequency is below 270kHz the phase resolution is 1 The higher frequency the lower phase resolution For example the frequency is at 1 MHz the phase resolutions is 3 6 3 3 Setup of Channel B Press key Channel to select CHB Alone Setups for frequency period amplitude waveform selection duty ratio and phase apply the same procedures as explained in the setup of channel A The difference is that there is no amplitude attenuation and DC offset in channel B 3 3 1 Set the Frequency of Channel B Sel
29. and LCD display through the interface circuitry When the key is pressed the MCU detects the action finds the code of key and executes the corresponding program The LCD display circuit adopts menu characters to display the working status and parameters of the instrument The knob on the front panel can be used to adjust the numeric digit on the cursor position Every 15 degree rotation will generate a trigger pulse Based on the pulse the MCU can determine the knob left rotation or right rotation If the rotation is left the digit on the cursor is subtracted by one If the rotation is right the digit is added by one Chapter 3 Operation Instructions 3 1 Operation Common Rules 3 1 1 Menu Selection If there is a triangle displayed on the right side of the menu it means this menu has several options Otherwise this menu has only one option Press one option key to select the corresponding option in this menu This instrument has ten functions and the five function keys Channel Sweep MOD BURST and SK are used to select these functions The five lines on the right side of LCD are the option menus which can be selected by pressing one of the five option keys located on the right side of LCD The selected option menu will change to green 3 1 2 Parameter Display The area under the waveform display is for parameter display The contents in this parameter area are divided into two parts One is the name of parameter displayed in
30. d For example send address RS232 command to select the RS232 interface The instrument will switch to the RS232 remote mode If the address of the instrument is 88 send 88RS232 To exit this remote control mode send 88LOCAL to make the instrument back to the normal key operation mode Otherwise neither the key operation nor the other remote controls can be used 4 4 Application Software In the automatic testing system the application software is a control program which is written by the testing engineers for the accurate control on the variety of instruments and devices Users have to read the details of this guide before starting to write the application program It is quite easy to program as long as you are familiar with the manual operations and transfer each manual operation to the program of each remote command gradually The application program can be written by a variety of computer languages 26 Test Equipment Depot 800 517 8431 99 Washington Street Melrose MA 02176 TestEquipmentDepot com 4 4 1 Enter the Programmable Mode After power on the instrument is in the manual operation mode When the remote command is received the instrument enters the remote operation mode At this time all the key functions are not available The instrument can only be operated by the remote command To return to the manual operation mode send the Address LOCAL for example S8LOCAL command from the computer
31. d on the frequency and amplitude of channel A 3 1 6 Input Mode Selection It is convenient to input the known data through the numeric keypad It makes the input to be set at only one step without the intermediate transition data For the partial modification of the input data or at the situation of monitoring the variation process of the input data the knob is usually more useful For a series of equal interval data input the step input method is the most efficient You can use the different ways to meet your requirement 3 2 Setup of Channel A Press key Channel and select CHA Alone function 3 2 1 Set the Frequency of Channel A Select Frequency option by the corresponding soft key The current frequency value changes to yellow Using the numeric keypad or rotary knob to input a new frequency value The function generator outputs the specified frequency at CHA Output 3 2 2 Set the Period of Channel A The frequency of channel A can also be set in the way of period Select Period by the corresponding soft key B n C Test Equipment Depot 800 517 8431 99 Washington Street Melrose MA 02176 TestEquipmentDepot com The current period value changes to yellow Input a new period value here by numeric keypad or rotary knob The instrument still uses the frequency synthesis and the input data is just converted to the right value when it is input and displayed Due to the limitation of the low resolution at low frequency wh
32. e VLSI components and surface mount technology Protection over voltage protection over current protection output short circuit protection for a few minutes reverse voltage protection e Frequency testing built in frequency counter capable of internal and external frequency signal testing O Remote control RS232 interface Check list e DDS function generator 1 O Operation manual l O Power cord l O RS232 software CD l Q9 test lead 1 e RS232 cable 1 e Q9 BNC clip test lead l AE A E II Tt OCUCHOT A Na IV Chapter PQuick Startin iesenii ienirt aa aT raa RAE T Ta ara 9 dd ZE a d T Z E 0 aaae Tag ZH Ara 42 1 LEPE as 1 1 1 1 Check the Function Generator and AGceSsones sse sees eee 1 1 1 2 Connect the Function Generator to Powers sese eee eee eee 1 1 2 Hront Panel and Rear Pad A a aa Sect os Beneath 1 1 3 Description of LCD Display sss sees eee 2 ESC neniun raei ea a reren ue den Eene e Eras rason Esa eaae ao ea oto En rasa S saa 3 ES E ENS 3 LAD SOft a e 3 1 4 3 Numeric Keypad TTT 3 LAA MIS OF LA A teh e ero eL lr eo al arado ela lo at dd 3 PACS Direction en e alo da eas e ete 3 1 5 Fundamental Operation id desi dasa wean snd eh data han dail asii 3 1 5 1 Function of Channel Aci dd ia 3 1 5 2 Function of Channel Brin aci 4 1 5 3 Frequency Sweep of Channel A seen 4 LS AvAmplitide S Weep A A TEA 5 1 5 5 Frequency Modulation FM sese 5 1 5 6 Burst Output of Channel A cernis Tada eaoaai daag Haan
33. e characteristics and any particular purpose We will not take any responsibility in cases regarding to indirect particular and ensuing damage such as modifications to the circuit and functions by the users repairing or component replacement by the users or damage during transportation For product improvement the specifications are subject to change without prior notice This manual is meant to be an operation guide to users and has been prepared with the utmost care However if you have any questions or note any errors or omissions please contact your local distributor Safety Instruction This chapter contains important safety instructions that you must follow when operating the instrument and when keeping it in storage Read the following before any operation to insure your safety and to keep the best condition for the instrument 1 Safety Terms and Symbols The following safety symbols may appear in this manual or on the instrument WARNING Identifies conditions or practices that could result in injury or loss of life Identifies conditions or practices that could result in damage to the instrument or to CAUTION other properties DANGER High voltage ATTENTION Refer to the manual gt gt gt Earth ground terminal 2 Safety Guidelines 1 e Before plugging into local AC mains check and make sure that the output voltage CAUTION is compatible to the load It is suggested to disconnect a load before plugging into
34. e command is the ASCII code delivered from the computer to the controlled equipment The controlled equipment works according to given command Each equipment has its own command in a specified format and definition In writing a new remote command user must strictly follow the format and definition of the equipment s command so as to give correct command for the controlled equipment to complete the work Remote command 1 Remote command 2 without digit and unit Inquiry command CHA AFREQ 1 31 MHz CHA SQUAR CHA AFREQ MR A A E TTT TTT 1 52 53 5 4 1 5 2 1 6 2 1 Function string 2 Option string 3 Data string 4 Unit string 5 Separate character 6 Question mark The remote command consists of the function string the option string the data string the unit string the separate character and the question mark Some commands do not include the data string and the unit string 4 3 1 Command String The instrument remote commands consist of the function string the option string the data string and the unit string shown in the tables below Both function and option strings use the uppercase characters whose definition is corresponding to the instrument functionality and option The data string consists of 10 digits of numbers from 0 to 9 decimal point and negative sign The unit string consists of the defined uppercase and lowercase characters depending on the data characteristics Except the characters in the table the other characters can
35. e to the left decease the DC offset value regardless of the DC offset value as positive or negative When the rotary knob tune across zero the offset value changes automatically between positive and negative signs 3 2 8 DC Voltage Output If the amplitude attenuation is set at fixed OdB the output DC offset value is the preset offset value Set the amplitude at OV the offset value can be set at any value within the range of 10V In this case the function generator becomes a DC voltage source to output preset DC voltage signal 3 2 9 Select the Waveform of Channel A The channel A can output 32 waveforms including Sine Square Triangle Pulse Noise Arbitrary waveforms These waveforms can be directly selected by waveform keys After selecting a waveform the CHA output will output the selected waveform and display the waveform on display area of parameters of channel A When the square waveform is selected in channel A the square duty ratio is default at 50 As to the other 27 waveforms which are not frequently used they are displayed as Arb in the upper portion of the LCD and can be selected 2934 with corresponding button The following table lists the code and waveform names of the 32 waveforms Code and name for 32 waveforms Code Waveform name Code Waveform name Code Waveform name Code Waveform name 00 Sine 08 Up stair 16 Exponent 24 Down stair 01 Square 09 Pos DC 17 Logarithm 25 Po bipulse 02 Triangle 10 Neg DC 18 H
36. ect Frequency by the corresponding soft key The current frequency value changes to yellow which means the frequency value can be modified and input via numeric keypad or rotary dial The function generator outputs the desired frequency signal on CHB output In channel B frequency period can also be set and displayed 3 3 2 Set the Amplitude of Channel B Select Amplitude by the corresponding soft key The current amplitude value changes to yellow which means the amplitude value can be modified and input via numeric keypad or rotary dial The function generator outputs the desired signal at CHB Output The amplitude unit of Channel B can only use Vpp but not Vrms The channel B does not have the amplitude attenuation or DC offset functions 3 3 3 Select the Waveform of Channel B The waveform of channel B is represented by the index number Select Waveform by the corresponding soft key applies the same operation as explained in section 3 2 9 14 3 3 4 Set the Harmonics of Channel B The frequency of channel B can be set and displayed as multiple times of channel A frequency That is channel B signal becomes the multiple N times harmonic signal of channel A signal Select B harmonics by the corresponding soft key Input harmonic times via numeric keypad or rotary dial Channel B frequency becomes the set multiple times of channel A frequency That means channel B signal becomes the multiple N times harmonic signal of chan
37. en the period is too big the function generator can only generate the frequency points with the bigger period interval Although the preset and displayed period is precise the real period of the output signal has relatively big variation Please pay attention to this point 3 2 3 Set the Amplitude of Channel A Select Amplitude by the corresponding soft key The current amplitude value changes to yellow Input a new amplitude data here by numeric keypad or rotary dial The function generator outputs the desired signal on the CHA Output The input and display of the Channel A amplitude value have two formats Vpp and Vrms Press key Vpp or mVpp after numeric input to input and display amplitude peak to peak value Press key Vrms or mVrms after numeric input to input and display amplitude true RMS value If press key Vrms and mVrms without amplitude data input the current amplitude value unit can be switched between the two formats Although the amplitude value has two formats the instrument still uses the peak to peak format internally and makes the format conversion on the data input and the data display Due to the limitation of the amplitude resolution there is difference between the format conversions For example if the Vpp of sine wave is 1 V the Vrms conversion value is 0 353 Vrms If the Vrms of sine wave is 0 353 Vrms the Vpp conversion value is 0 998 V In most cases this difference is within the error range The RMS
38. er cord for damage of the vinyl cover and overheating of the plug and cord stopper Check the terminal screws and binding posts for loosening Remove dust from the inside of the casing and ventilation holes of the cover by using a compressed air of the exhaust air of a vacuum cleaner 6 Cleaning e Before cleaning disconnect the AC mains e To clean the power supply use a soft cloth dampened in a solution of mild detergent and water Do not spray cleaner directly onto the instrument since it may leak into the cabinet and cause damage e Do not use chemicals containing benzene benzene toluene xylene acetone or similar solvents Do not use abrasive cleaners on any portion of the instrument HI Test Equipment Depot 800 517 8431 99 Washington Street Melrose MA 02176 TestEquipmentDepot com Introduction This user s guide is used for all models of this series of DDS function generator The last two digits in the model number represent the maximum frequency of the channel A There are four models to choose from this series with max frequency range of 5MHz 10MHz 15MHz and 20MHz This series of arbitrary waveform DDS function generator uses Direct Digital Synthesis DDS technology Its outstanding performance and system features make this function generator a perfect solution for your testing requirement The simplified and optimized design of the front panel and dual language English Chinese TFT LCD display int
39. erface make your testing much easier for operation and observation Additionally the extendable optional functions can also improve your system characteristics Technical characteristics and system features e High accurate Frequency up to the 10 order of magnitude e High Frequency Resolution full range resolution is 40 mHz 6 No Range Limitation no frequency level switch frequency set directly by digit keypad No Frequency Transition momentarily switch to the stable value on phase and amplitude without transition and distortion Precise Output Waveform output waveform is synthesized by the preset function calculation values very accurate and less distortion e Multiple Waveform output 32 kinds of the pre stored waveforms Pulse Characteristics set accurate pulse duty cycle Harmonic Wave Characteristics output the fundamental and harmonic waves with adjustable phase Sweep Characteristics frequency sweep and amplitude sweep free to set the start and stop frequency e Modulation Characteristics output FM signals e Shift Keying Characteristics output FSK ASK and PSK signals e Burst Characteristics output pulse waveform with burst count Store Characteristics store 40 sets of the user parameters and recall O Counter Characteristics count the frequency period amplitude RMS value or peak to peak value O Operation mode Key operation for all functions parameters settings by numeric keypad or rotary dial e High reliability us
40. et has a preset burst count and there is an interval time between very set of burst 3 10 1 Set the Carrier Frequency Signal of channel A is used as the output burst signal Therefore channel A signal frequency and amplitude should be firstly set up Select Carrier Freq by the corresponding soft key The carrier frequency value becomes yellow Input a new carrier frequency value here via numeric keypad or rotary dial 3 10 2 Set the Carrier Amplitude Select Carrier AMP by the corresponding soft key The carrier amplitude value becomes yellow Input a new carrier amplitude value here via numeric keypad or rotary dial 3 10 3 Set the Burst Count Select N Cycles by the corresponding soft key The burst count value becomes yellow Input a new burst count number here via numeric keypad or rotary dial If the burst frequency is fixed the maximum value of the burst count is limited The lower burst frequency the longer burst period and the bigger the burst count number to be set Vise visa the smaller burst count number is If the burst frequency is not set the burst count can be set firstly and then the burst frequency value is adjusted in order to keep an appropriate time interval between each burst 3 10 4 Set the Burst Frequency Select Burst Freq by the corresponding soft key The burst frequency changes to yellow Input a new burst frequency here via numeric keypad or rotary dial When burst is in operation in channel A
41. gic 1 data logic 0 1 stop bit logic 1 4 2 3 Transmission Rate In this instrument the transmission rate is default 19200bits s and can be reset by software 4 2 4 Interface Connection Use a RS232 cable to connect the RS232 connector on the rear panel to the COM1 or COM2 connector on the computer E 4 2 5 System Construction In one system the maximum number of connected instruments is 99 units and the total length of connection cable cannot exceed 100 meters 4 2 6 Environment The RS232 adapts the data transmission in the common lab and production environment without heavy electrical interference 4 2 7 Address Information In the programmable mode the instrument starts to receive the message from computer checks the index bit and determines the received message is either address message or data message If it is an address message check if the received address matches its own address or not if not ignore all following messages and wait for the next address message If the address matches the instrument starts to receive the following data message until the whole message received 4 2 8 Data Information After receiving the data message the instrument verifies and stores the data in the memory If the received character is the line feed Chr 10 it means it is the end of the data message The instrument starts to execute each operation in this remote command 4 3 Remote Command The remot
42. hannel B 16 Test Equipment Depot 800 517 8431 99 Washington Street Melrose MA 02176 TestEquipmentDepot com Generally speaking the carrier frequency should be at least 10 times higher than the modulation frequency 3 6 3 Set the Frequency Deviation Select FM Deviation by the corresponding soft key The frequency deviation value changes to yellow Input a new deviation value here via numerical keypad or rotary dial Deviation depth shows the variations of the carrier signal frequency during the frequency modulation It is more intuitional to show the variation in the way of carrier waveform period variation Variation in the frequency of modulated waveform is shown as the equation below DEVI 100 SHFT PERD DEVI is the modulation frequency deviation SHIFT is the peak variation PERD is the period of the carrier signal at the zero frequency deviation In the modulation demonstration to have clear observation of the frequency variation a bigger frequency deviation should be set In practices to reduce the bandwidth of the carrier signal the frequency deviation is usually less than 5 3 6 4 Set the Modulation Waveform Since the signal of channel B as the modulation signal the Channel B waveform is actually the modulated waveform Select MOD Wav by the corresponding soft key The index number changes to yellow Input the correct index number by numeric keypad or rotary dial so as to select corresponding waveform The
43. have in testing results but the slower tracking to the frequency variation This is applicable to test the long term frequency stability The shorter gate time the less valid digits to have in testing results the faster tracking to the frequency variation which is suitable to frequency testing requiring a short time of stability 21 Test Equipment Depot 800 517 8431 99 Washington Street Melrose MA 02176 TestEquipmentDepot com 3 14 System Setup Press key Utility to enter system setup mode The system interface is displayed Users can store or recall system setup parameters and carry out the programmable interface operation 3 14 1 Store Parameters Press the soft key corresponding to Recall to step down to Store to enter the parameter storage mode All preset parameters can be stored into the memory of the instrument The instrument provides 39 index numbers for the parameter memories starting from index NO 1 to index NO 39 Memories of index No 1 39 are available for user defined setting storage except memory of index NO 0 Memory index NO 0 is for the storage of default parameters setup 3 14 2 Recall Parameters Select Recall by the corresponding soft key Input recall index number 0 to 39 to recall the stored settings in each memory Input number 0 recalls the default parameter setting of the instrument After the parameters are recalled the instrument outputs the signal based on the recalled parameters
44. ig by the corresponding soft key The signal of TTL_A will be used as burst source for continuous burst Set external TTL burst Press the soft key corresponding to TTL_A Trig Press this soft key once more to step down to EXT Trigge to select the external TTL burst Input external signal from Count In terminal on the rear panel The input external signal will be used as a burst source 1 5 7 Burst Count of Channel B Press key Channel to select CHB Alone Next press key Burst to go to CHB Burst Apply the same setting procedure as explained in section 1 5 6 for setting burst of channel A 1 5 8 FSK Modulation FSK Press key SK to select CHA FSK Set carrier frequency set carrier frequency at 15kHz Select Carrier Freq by the corresponding soft key then press the key corresponding to 1 5 kHz Set carrier amplitude set carrier amplitude at 2Vpp Select Carrier AMP by the corresponding soft key then press the key corresponding to 2 Vpp Set hop frequency set hop frequency at 2kHz Select Hop Freq by the corresponding soft key then press the key corresponding to 2 kHz Set interval time set interval time at 20ms Select Interval by the corresponding soft key then press the key corresponding to 2 0 ms 1 5 9 Amplitude Shift Keying ASK Press key SK to select CHA ASK The setups of carrier frequency carrier amplitude and interval time here appl
45. key The beeper can be turned on or off here After power on the instrument the beeper is default as ON the key sound is on Every press on a key there is a sound going with To turn off the beeper press by the corresponding soft key to Beep Off 3 14 5 Choose A Language Select a language by the corresponding soft key There are only two languages available in the system English Chinese simplified Chinese Traditional 299 Chapter 4 Programmable Interface This chapter introduces the usage of the program interface Through the study of this chapter you will learn how to setup the testing system and use the testing software to program the instrument 4 1 Interface Application Nowadays the application of computer is prevalent The traditional test equipment is gradually replaced by the digital test devices Most of the manual testing tasks have been replaced by the automatic testing systems based on the computer control technology which is an inevitable trend in testing amp measuring field Today almost all high end and middle end test equipment has the communication interfaces With the interfaces the test equipments can be connected to the computer with the communication cables to make a testing system During the test all the devices or equipments in the system can communicate with each other through the interfaces and cables Based on the preprogrammed test software the remote computer can control various devices and
46. local AC mains Do not use this instrument near water Do not operate or touch this instrument with wet hands Do not open the casing of the instrument when it is connected to AC mains Do not use the instrument in an atmosphere which contains sulfuric acid mist or other substances which cause corrosion to metal e Do not use the instrument in a dusty place or a highly humid place as such will cause instrument reliability degradation and instrument failures e Install the instrument in a place where is free from vibration e Install the instrument in a place where the ambient temperature is in range of 10 70 C Note that the instrument operation may become unstable if it is operated in an ambient temperature exceeding the range of 0 40 C 3 Power Supply AC Input voltage 110V 120V 220 240V 410 50 60Hz WARNING Connect the protective grounding conductor of the AC power cord to an earth ground to avoid electrical shock 4 Fuse Fuse type 110 120V T2A 250V or 220 240V T1A 250V Make sure the correct type of fuse is installed before power up Replace the AC fuse with the same type and rating as the original fuse Ae Disconnect the power cord before fuse replacement Make sure the cause of fuse blowout is fixed before fuse replacement 5 Maintenance Inspection Inspect the instrument at regular intervals so that it maintains its initial performance for a long time e Check the input pow
47. make them work coordinately For example first the remote computer sends a command to the function generator to request it to output an appropriate signal Secondly the computer sends commands to the frequency meter and voltage meter to measure the frequency and voltage After collecting all measurement data the computer processes and analysis the data and finally prints out the test report In this example all complicated tasks are completed by the automatic testing system What the testing engineer needs to do is to write a testing program A good testing system can not only save a lot of labor and improve the efficiency but also provide the reliable results and reduce the risk of the mistakes and faults caused by the testing engineer In some situations the automatic testing system can even complete the test tasks which cannot be done by the manual test ways 4 2 RS232 Interface The instrument has the option to install the RS232 interface which is compliant to EIA RS232 standards The RS232 interface is the serial asynchronous communication interface It has the characteristics of the long transmission distance and less number of transmission wire Most of the current computer has the RS232 interface 4 2 1 Interface Voltage Level Logic 0 5 V to 15 V Logic 1 5 V to 15 V 4 2 2 Transmission Format Each transmission frame consists of 11 bits 1 start bit logic 0 8 data bits ASCH code 1 index bit address lo
48. n concepts and provides the specific details on the internal operations of the function generator 2 1 Principle Diagram KNOB KEYPAD Digital s Circuitry CLOCK MODULATION ENPUT FM TTL OUTPUT E AMPLITUDE VOLTACE POWER en TPUT CONTROL P AMPLIFIER K AMPLIFIER 20 60dB_ S SETTING OUTPUT gt PROTECTION OUTPUT S K AMPLITUDE POWER uP LPF K CONTROL AMPLIFIER m OUTPUT B 2 2 Principle of Direct Digital Synthesis In order to generate a voltage signal the traditional analog signal source generally uses the discrete electronic components to build oscillation circuitries in variety ways The accuracy of frequency is not only low but also very unstable The production and testing procedures are very complicated and time consuming Moreover it is not convenient for the frequency setting and computer programming The Direct Digital Synthesis DDS technology is a new signal generation technique DDS does not consist of any oscillating components It applies a stream of digital data which represents the desired waveform pre stored in memory to the input of digital to analog DAC converter The DAC converts the data and outputs a series of voltage steps approximating the desired waveform For example to synthesize a sine waveform first the function y sin x is digitized then the digitized value y is
49. n the start frequency Otherwise the sweep can not operate 3 4 2 Set the Step Frequency After the start frequency and the stop frequency are set the sweep rate can be determined according to the required accuracy In a sweep process the bigger the step frequency the less numbers of frequency points and lower accuracy the shorter time taken in a sweep process The smaller step frequency the more numbers of frequency points and higher accuracy the longer time taken in a sweep process Select Step F by the corresponding soft key the current step frequency changes to yellow Input a new step frequency data here by numeric keypad or rotary dial 3 4 3 Select Sweep Mode Select one of the three sweep modes by the corresponding soft key Up Sweep Mode Down Sweep Mode Up Down Sweep Mode Up Sweep Mode the output signal sweeps repetitively from the start frequency to the stop frequency at the sweep rate Down Sweep Mode the output signal sweeps repetitively from the stop frequency to the start frequency at the sweep rate Up Down Sweep Mode the output signal sweeps from the start frequency to the stop frequency at the sweep rate then sweeps from the stop frequency to the start frequency at the same sweep rate 15 3 4 4 Set Step Time After the start frequency the stop frequency and the sweep rate are set the interval time can be determined according to sweep speed The shorter interval time the faster sweep speed The longer inter
50. nel A signal At this time phase of channel A and B signals has stable synchronization If channel B is not selected channel A and B will not have synchronization Although channel B frequency is set at a multiple time of channel A frequency channel A and channel B may not able to reach synchronization Therefore to make sure of stable phase synchronization of channel A and B user must first set up channel A frequency next select B harmonics and set harmonic multiple time so that channel B frequency can change automatically 3 4 Frequency Sweep Press key Sweep and select A SweepF option The function generator outputs the frequency sweep signal at the CHA Output The sweep mode of output frequency is step sweep The output frequency automatically increases or decreases by a step value in a certain interval time Start frequency stop frequency step frequency and interval time are free to be set by the users 3 4 1 Set the Start and Stop Frequency The start point of frequency sweep is start frequency and the stop point is stop frequency To set the start frequency press key Start F by the corresponding soft key and display the start frequency Input a new start frequency value via numeric keypad or rotary dial To set the stop frequency select Stop F by the corresponding soft key and display stop frequency Input a new stop frequency value via numeric keypad or rotary dial Note the stop frequency must be greater tha
51. not be used Otherwise the error occurs 24 The Table of Function Command Option String Option Frequency of Channel A CHA Burst of Channel A Frequency of Channel B CHB Burst of Channel B Frequency Sweep of Channel A FSWP FSK of Channel A Amplitude Sweep of Channel A ASWP ASK of Channel A Frequency Modulation of Channel A FM PSK of Channel A External Frequency Measurement COUNT TTL Return to Local LOCAL RS232 control System SYS The Table of the Option Command Option String Option String Option CHA waveform AWAVE Recall Parameter RECAL Hop Amplitude CHA offset AOFFS Measuring Frequency MEASF Hop Frequency CHA frequency AFREQ Software Version VER Hop Phase CHA attenuation AATTE Burst Count NCYCL External Trigger CHA period APERD Burst Frequency BURSF External Modulation CHA duty cycle ADUTY Single Trigger TRIGG System Reset CHB frequency BFREQ Single Burst ONCES Phase CHB harmonic Wave BHARM FM Deviation Depth DEVIA True RMS CHB period BPERD Modulation Waveform MWAVE Language Setup CHB duty cycle BDUTY Modulation Frequency MODUF Carrier Amplitude TTL_A Frequency TTLAF Peak to peak value VPP Carrier Frequency TTL_A Duty Cycle TTLAD Beep Sound BEEP Gate time TTL_B Frequency TTLBF Interval Time INTVL Stop Amplitude TTL_B Duty Cycle TTLBD Interface Address ADDR Stop Frequency TTL_A Trigger TTLTR Sweep Mode MODEL Auto Sweep Step Amplitude STEPA Start Amplitude STARA Store Parameter Step Frequency STEPF Start Frequency STARF Output Switch CH
52. o Set step frequency of channel A set step frequency at 12 5Hz Into the frequency menu select Step Freq by the corresponding soft key then press key 1 2 5 and the soft key corresponding to Hz After this setup every press on key A increase the frequency of channel A increase by 12 5Hz and very press on key W decrease the frequency of channel A by 12 5Hz Apply the same procedure in setup of CHA amplitude 1 5 2 Function of Channel B Press key Channel to select CHB Alone Set frequency and amplitude of channel B apply the same procedure of setting frequency and amplitude of channel A as explained in section 1 5 1 Select waveforms of channel B select triangle wave Press the soft key corresponding to Ramp Set harmonic wave of channel B set frequency of channel B as a triple harmonic wave of channel A Into the wave menu select Phase by the corresponding soft key press the soft key corresponding to Harmonic then press keys 3 and the soft key corresponding to Time Set phase difference of channel B set phase difference of channel B at 90 Into the wave menu select Phase by the corresponding soft key then press keys 9 0 and the soft key corresponding to 1 5 3 Frequency Sweep of Channel A Select A SweepF by the corresponding soft key Set stop frequency set stop frequency at 50kHz Select Stop Freq by the corresponding soft key then press keys 5
53. ode Input external burst signal from the Count In terminal on the rear panel To validate Count In function the generator must have frequency counter input Burst count function can be used to test the dynamic features of audio equipments as well as to calibrate a counter 3 11 Burst Output of Channel B Press key Channel to select CHB Alone Next press key Burst to enter CHB Burst mode The function generator outputs a waveform with a specified number of cycles at the burst frequency continuously at the CHB Output There is a time interval between each burst Parameter settings of channel B burst is the same as setting procedure of channel A burst parameter setting Set the Burst Frequency Select Burst Freq by the corresponding soft key The burst frequency changes to yellow Input a new burst frequency here via numeric keypad or rotary dial In channel B burst operation TTL_B signal is used as the burst signal The burst frequency actually is the TTL_B frequency The burst frequency is determined by the values of the Channel B frequency and the burst count The multiple of channel B signal period value and burst count number is the time needed for a set of burst Burst period value should be bigger than the interval time so as to make sure of a suitable interval time between each set of burst Otherwise all sets of burst will be output continuously and cannot be a burst signal 3 12 TTL Output Press key
54. onding to kHz Set modulation deviation set modulation deviation at 5 2 Select FM Deviation by the corresponding soft key then press key 5 2 and the key corresponding to Set modulation waveform set modulation waveform actually it is waveforms of channel B as Triangle wave Select Mod Wav by the corresponding soft key then press key 2 and the key corresponding to No Set external modulation Select Mod Wav by the corresponding soft key press the same key again to select External 1 5 6 Burst Output of Channel A Press key Channel to select CHA Alone Next press key Burst to go to CHA Burst Apply the same setting procedures as described in section 1 5 1 for frequency and amplitude setup Set burst count set burst count as 5 cycles Select N Cycles by the corresponding soft key then press keys 5 and the key corresponding to Cycl Set burst frequency set burst frequency at 50Hz Select Carrier Freq by the corresponding soft key then press keys 5 0 and the key corresponding to Hz Set single burst mode Press the soft key corresponding to TTL_A Trig Press this soft key twice to step down to Single to select the signal bust mode Press key CHA Output Trigger for one time will output burst for one time If the signal bust mode is not selected pressing on key CHA Output Trigger starts a continuous burst Set internal burst Select TTL_A Tr
55. pA Settings of different sweep parameters sweep mode single sweep and sweep monitor apply the same procedures as explained in section Channel A set up To have continuous amplitude variations user shall firstly set attenuation of channel A In the sweep process the generator attenuates according to channel A fixed attenuation so as to avoid frequent relay switch during auto sweep 3 6 Frequency Modulation FM Press key MOD to select CHA FM The function generator outputs the frequency modulation signal on the CHA Output 3 6 1 Set the Carrier Frequency Select Carrier Freq by the corresponding soft key The carrier frequency value changes to yellow Input a new carrier frequency value here via numeric keypad or rotary dial In the frequency modulation mode the signal of Channel A is the carrier signal and the carrier frequency actually is the frequency of Channel A In the frequency sweep mode the clock signals of DDS synthesizer are switched to from the fixed reference clock to the programmable reference clock the accuracy and stability of the carrier frequency may decrease 3 6 2 Set the Modulation Frequency Select MOD Freq by the corresponding soft key The modulation frequency value changes to yellow Input a new modulation frequency value via numeric keypad or rotary dial In the frequency modulation mode the signal of Channel B is the modulation signal So the modulation frequency actually is the frequency of C
56. s the alternative variation of the carrier frequency and the hop frequency The interval time of alternation is adjustable 2492 3 7 1 Set the Carrier Frequency Select Carrier Freq by the corresponding soft key The carrier frequency value changes to yellow Input a new carrier frequency value here via numeric keypad or rotary dial In the FSK mode the signal of the channel A is the carrier signal The first frequency value is the carrier frequency 3 7 2 Set the Hop Frequency Select Hop Freq by the corresponding soft key The hop frequency value changes to yellow Input a new hop frequency value via numeric keypad or rotary dial The hop frequency is the second frequency of the channel A 3 7 4 Set the Interval Time Select Interval by the corresponding soft key The interval time value changes to yellow Input a new interval time via numeric keypad or rotary dial 3 8 Amplitude Shift Keying ASK Press key SK again to step down to CHA ASK option The function generator outputs the ASK signal on the CHA Output The upper left portion of the LCD displays the ASK waveform The amplitude of output signal is the alternative variation of the carrier amplitude and the hop amplitude The interval time of alternation is adjustable 3 8 1 Set the Carrier Amplitude Select Carrier AMP by the corresponding soft key The carrier amplitude value changes to yellow Input a new amplitude value via numeric keypad or rotary
57. tion caused by PSK signal it is hard to have synchronization on the oscilloscope and therefore cannot observe a stable waveform If the frequency of the channel B is set at the same value of carrier frequency and use channel B signal as synchronization burst signal a stable PSK signal waveform can be observed However the PSK waveform displayed on the LCD is just an extreme special case for the purpose of direct and easy explanation of PSK process There are conditions for operating the special case the carrier signal period should be exactly same as the interval time of two alternative phase signals hop phase at 180 and hop at the phase value of 0 In practices it is very difficult to meet the conditions required If we set the carrier frequency at 1Hz interval time as 1s hop phase at 180 we can observe a similar waveform on the oscilloscope But the waveform can only stay for a very short time because the actual interval time is not exactly same as carrier frequency period Adjust the interval time to make it as close as possible to the carrier frequency period so as to have a longer display of the waveform 3 10 Burst Output of Channel A Press key Channel to select CHA alone and then press key Burst to go to channel A burst mode The LCD will display CHA Burst in the upper portion The function generator outputs a waveform with a specified number of cycles at the burst frequency continuously at CHA output Every s
58. to tell the instrument back to the manual operation mode Or press key SYS to return to manual operation 4 4 2 Tips for Writing a Program Users have to pay attention to the program main points below when use the remote command to program 1 Strictly follow the remote command format including the uppercase and lowercase characters in the command code Otherwise the instrument will consider the command as a wrong message and ignore the operation 2 Users should be familiar with the manual operation firstly and make sure the remote command sequence exactly same as the manual operation The right sequence of the command should be the function string the option string the data string and finally the unit string If the program sequence is not correct or the string does not match the corresponding functionality although the instrument executes the code and does not give any error notice the result may be wrong For example set the frequency of the channel A at 100 kHz remote command 100 AFREQ kHz 100 This is a string in wrong sequence Another example select the No 3 waveform of channel B remote command CHA BWAVE 3No the command and function are not matching 4 4 3 Application Example The application examples of the various types of the remote command are shown as below Examplel Channel A Single output Sine wave Frequency 1MHz RS232 mode 88 CHA AWAVE 0 No 88CHA AFREQ 1 MHz Example 2 Channel B Single output Triangle wave
59. ude and phase characteristics of the output signal will not be so good The maximum output amplitude is also affected The higher frequency the higher amplitude and the more distortion in output waveform Output frequency 10MHz 15MHz max output amplitude 15Vpp Output frequency 15MHz 20MHz max output amplitude 8Vpp 3 2 7 Set the Offset of Channel A Select Offset by the corresponding soft key The current offset value is shown on the LCD display Enter a new offset data here by numeric keypad or rotary dial The function generator outputs the desired signal at the CHA output Please note that the sum of half of the signal output amplitude value and the offset value should be less than 10V so as to make sure the offset signal peak value is less than 10V Otherwise there will be amplitude distortion Besides when Channel A is at AUTO mode in attenuation the output offset attenuates as per amplitude attenuation When amplitude Vpp value is above about 2V the actual output offset is the preset offset value When amplitude Vpp value is approximately between 0 2V 2V the actual output offset is 10 of the preset offset value When the amplitude Vpp value is approximately less than 0 2V the actual output offset is 1 of the preset offset value When adjusting DC offset value of the signal the rotary knob is more frequently used than numeric keypad As a common rule tune the rotary knob to the right to increase DC offset level whil
60. val time the slower sweep speed However practically the real interval time is the sum of the preset interval time and the software execution time When the interval time is very short the software execution time can not be ignored The actual interval time may have a big difference with the preset interval time Select Interval by the corresponding soft key the step time changes to yellow Input a new interval time here by numeric keypad or rotary dial 3 4 5 Manual and Auto Sweep After the A SweepF mode is selected the sweep mode is default as manual mode Select Manual Sweep by the corresponding soft key the sweep process stops at once The output signal will keep at the stop stage without any changes The current frequency value is shown on the LCD display After the sweep process stops press key CHA output Trigger once the sweep process goes on by one step According to the desired sweep mode the frequency of Channel A increases or decreases by one sweep step value In this way users can observe the detailed variations in the frequency sweep If Auto Sweep is selected in this menu this operation ceases the manual sweep and starts auto sweep Users can have dynamic monitor of the sweep process Frequency of channel A changes simultaneously according to the sweep process The sweep process stops when setting of other sweep parameters is in operation 3 5 Amplitude Sweep Press key Sweep to select A Swee
61. y the same setting procedure of explained in the above section 1 5 8 Set hop amplitude set hop amplitude at 0 5Vpp Select Hop Amp by the corresponding soft key then press the key corresponding to 0 5 Vpp 1 5 10 Phase Shift Keying PSK Press key SK to step down to CHA PSK function The setups of carrier frequency carrier amplitude and interval time here apply the same setting procedure of explained in the above section 1 5 8 Set hop phase set hop phase at 180 Select Hop Phase by the corresponding soft key then press the key corresponding to 1 8 0 6 Test Equipment Depot 800 517 8431 99 Washington Street Melrose MA 02176 TestEquipmentDepot com 1 5 11 System Initialization After power on the system initialization of the instrument displays the following parameters CHA and CHB waveform Sine CHA and CHB frequency 1kHz CHA and CHB amplitude 2Vpp CHA and CHB duty cycle 50 CHA attenuation AUTO CHA offset 0V CHB harmonics 1 0 Time CHB phase offset 0 Step frequency 10Hz Gate time 100ms Start frequency 500Hz Stop frequency 5kHz Interval time 10ms Sweep mode UP Carrier frequency 50kHz Carrier amplitude 2Vpp Modulation frequency 1kHz Modulation waveform Sine Modulation deviation 5 Chapter 2 Principle of the Function Generator In order to help you to better understand the internal operation of the instrument this chapter describes the basic signal generatio

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