Home

User manual

1. r CHA Frequency CHA Amplitude Function key CHA Alone sine CHB Alone sine Sweep Sweep CHA frequency CHB frequency Start frequency Start amplitude CHA period CHB period Stop frequency Stop amplitude CHA amplitude CHB amplitude Step frequency Step amplitude CHA waveform CHB waveform Sweep mode Sweep mode CHA duty cycle CHB duty cycle Interval time Interval time opon CHA attenuation CHB harmonic wave Single sweep Single sweep CHA offset CHB phase Auto sweep Auto sweep Step frequency Step amplitude CHA phase Function key CHA Burst CHB Burst System Setup FM carrier frequency carrier frequency Recall parameter Carrier frequency carrier amplitude carrier amplitude Store parameter Carrier amplitude Burst count Burst count Remote address Modulation frequency option Single burst Single burst Baud rate setup FM deviation External burst External burst Language setup Modulating waveform TTL_A burst TTL_B burst Beeper control Software version Function key FSK ASK PSK Carrier frequency Carrier frequency Carrier frequency i Carrier amplitude Carrier amplitude Carrier amplitude poa Hop frequency Hop amplitude Hop phase Interval time Interval time Interval time Function key TTL Output Counter TTL_A frequency External frequency measurement option TTL_A duty cycle Gate time TTL_B frequency TTL_B duty cycle 1 4 Key Description There are 26 ke
2. 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 Before cleaning disconnect the AC mains 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 Do not use chemicals containing benzene benzene toluene xylene acetone or similar solvents Do not use abrasive cleaners on any portion of the instrument MI Introduction This operation manual 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 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 LCD display interface 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 magni
3. T TL_A Duty option The TTL_A duty cycle value is shown on the LCD Input a new TTL_A duty cycle value by numeric keypad or rotary dial 3 12 3 Set the TTL_B Frequency Press key Menu and select TTL_B Freq option The TTL_B frequency value is shown on the LCD Input a new TTL_B frequency value by numeric keypad or rotary dial 3 12 4 Set the TTL_B Duty Cycle Press key Menu and select TTL_B Duty option The TTL_B duty cycle value is shown on the LCD Input a new TTL_B duty cycle value by numeric keypad or rotary dial 3 13 Measure External Frequency This function is available only when the user chooses to install the frequency counter Press key Counter to go to the external measurement mode The LCD display shows the external measurement interface In this mode the instrument can be used as a frequency counter 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 Count In terminal on the rear panel Press Menu and select Measure Freq 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 Frequency and Coun
4. 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 Amplitude accuracy 1 2mVrms high impedance true RMS frequency at 1kHz Amplitude stability 0 5 3 hours Amplitude flatness 5 frequency lt 10MHz 10 frequency gt 10MHz Output impedance 50Q 6 1 4 DC Offset Characteristics Offset range 10Vdc high impedance attenuation 0dB Resolution 20mVdc Offset 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 Down Manual sweep step time 32 6 1 6 Modulation Characteristics Carrier signal channel A signal Modulation signal internal signal of channel B or external signal FM deviation 0 20 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 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 Characte
5. MOD and select ASK The instrument will output the ASK signal with the default parameters at CHA output Set the carrier amplitude set the carrier amplitude at 2 Vpp Press key Menu and select Carrier Ampl next press keys 2 Vpp The setup of other ASK parameters will be introduced in section 3 8 1 5 8 PSK Modulation of the Channel A Press key MOD and select PSK The instrument will output the PSK signal with the default parameters at CHA output Set the hop phase set the hop phase at 180 Press key Menu and select Hop Phase next press keys 1 8 0 The setup of other PSK parameters will be introduced in section 3 9 1 5 9 Burst Output of the Channel A Select CHA Alone then press key Burst and select CHA Burst The instrument will output the burst count signal with the default parameters at CHA output Set the burst count set the burst count as 5 cycles Press key Menu and select Cycles next press keys 5 CY CL The setup of other burst parameters will be introduced in section 3 10 1 5 10 Burst Output of the Channel B Select CHB Alone then press key Burst and select CHB Burst The instrument will output the burst count signal with the default parameters at CHB output Set the burst count set the burst count as 5 cycles Press key Menu and select Cycles next press keys 5 CY CL The setup of other burst parameters will be introdu
6. MOD and select FM option FM is shown on the upper left of LCD The function generator outputs the frequency modulation signal on the CHA Output 3 6 1 Set the Carrier Frequency Press key Menu and select Carrier Freq option A new carrier frequency data can be input here by numeric keypad or rotary dial Press the soft key corresponding to the frequency units to confirm the new data input In the frequency modulation mode the signal of Channel A is used as the carrier signal and the carrier frequency is the frequency of Channel A In this mode the clock signals of DDS synthesizer are switched from the fixed reference clock to the programmable reference clock the accuracy and stability of the carrier frequency may decrease 17 3 6 2 Set the Modulation Frequency Press key Menu and select Mod Freq option A new modulation frequency data can be input here by numeric keypad or rotary dial Press the soft key corresponding to the frequency units to confirm the new data input In the frequency modulation mode the signal of Channel B is the modulation signal and the modulation frequency is the frequency of Channel B Generally the carrier frequency should be at least 10 times higher than the modulation frequency 3 6 3 Set the Frequency Modulation Deviation Press key Menu and select FM Deviation option A new frequency modulation deviation data can be input here by numeric keypad or rotary dial Press th
7. detailed instruction has been described in section 3 13 5 2 Power Amplifier If users choose to purchase the power amplifier the power amplifier board will be installed in the instrument This is an independent part of the instrument with input terminal power amplifier input and output terminal 2 time power amplifier output located on the rear panel of the instrument When using the power amplifier use a connecting cable to input the signal to the input terminal power amplifier input There will be a 2 time amplified signal in the output terminal 2 time power amplifier output The input signal can be the channel A signal or channel B signal or external signal 5 2 1 Input Voltage The power amplifier can amplify the input voltage by 2 times The maximum output amplitude is 22Vpp Therefore the maximum input amplitude should not exceed 11Vpp Input amplitude exceeds this limit will cause distortion 5 2 2 Frequency Range The frequency range of power amplifier is 10Hz 150kHz Amplitude flatness within this frequency range is better than 3 and sine distortion is better than 1 The maximum testing frequency is up to 200kHz 5 2 3 Output Power The equation for output power of power amplifier is P V R P is the output power with the unit of W V is the output amplitude RMS value with the unit of Vrms R is the load resistance with the unit of Q The maximum output amplitude is up to 22Vpp 7 8Vrms The minimum
8. dial Press the key corresponding to the frequency units to confirm the new data input In the FSK mode the signal of the channel A is the carrier signal The carrier frequency is the first frequency value of channel A signal 3 7 2 Set the Hop Frequency Press key Menu and select Hop Freq option Input a new hop frequency here by numeric keypad or rotary dial Press the key corresponding to the frequency units to confirm the new data input The hop frequency is the second frequency value of channel A signal 3 7 3 Set the Interval Time Press key Menu and select Interval option Input a new interval time data here by numeric keypad or rotary dial Press the key corresponding to the time units to confirm the new data input 3 8 Amplitude Shift Keying ASK Press key MOD and select ASK option The upper left portion of the LCD displays A_ASK The function generator outputs the ASK signal on the CHA Output 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 Press key Menu and select Carrier Ampl option Input a new carrier amplitude data here by numeric keypad or rotary dial Press the key corresponding to the amplitude units to confirm the new data input In the ASK mode the channel A signal is the carrier signal The carrier amplitude is the first amplitude value of ch
9. 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 HSS Earth ground terminal N Safety Guidelines A 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 local AC mains Do not use this instrument near water Do not operate or touch this instrument with wet hands Do not open the
10. frequency 100 0000000Hz Chapter 2 Principle of the Function Generator In order to help you better understand the internal operation of the instrument this chapter describes the basic signal generator concepts and provides the specific details on the internal operations of the function generator 2 1 Principle Diagram LCD KNOB KEYPAD DIGITAL MCU CLOCK CIRCUIT MODULATION INPUT Y a FM LPF COMP gt TTL OUTPUT OUTPUT AMPLITUDE VOLTAGE POWER gt I CONTROL AMPLIFIER gt AMPLIFIER ATTENUATION i 20 60dB OFFSET E OUTPUT gt SETTING PROTECTION A OUTPUTA AMPLITUDE POWER DD S TEE CONTROL AMPLIFIER OUTEUTE 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
11. 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 while to the left to decrease 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 9 DC Voltage Output When the attenuation of channel A is set at OdB the output offset is the preset offset value regardless of amplitude values If the amplitude value is set at OV the offset value can be set at any value between 10V and 10V In this situation the instrument becomes a DC power source which can output preset DC voltage signal 3 2 10 Select the Waveform of Channel A There are 32 kinds of waveforms in channel A Press keys Shift Wave to select CHA Wave the current waveform name and index number are shown on the bottom of the LCD display Enter the index number by using the numeric keypad or rotary knob press the soft key corresponding to No to confirm the index number input Users can use the shortcut function key on the front panel to select the 4 frequently used waveforms Press keys Shift to select sine wave Press keys Shift TH to select square wave Press keys Shift to select triangle
12. load resistance is 242 As the ambient temperature increases the output signal frequency increases too The lower output signal distortion is required the smaller the max output power is Generally the maximum output power can be up to 7W 8Q or 1W 500 5 2 4 Output Protections The power amplifier has short circuit protection and over heat protection It may not be burnt out in common operation However to prevent damage to power amplifier s performance long time short circuit output should be avoided Please also avoid to frequently using the maximum value of the frequency amplitude and load 30 5 3 RS232 If users choose to purchase RS232 interface user can remote control the instrument from a computer 2345 Chapter 6 Technical Specifications 6 1 Output Characteristics of Channel A 6 1 1 Waveform Characteristics Waveform type 32 waveforms including Sine Square Triangle Ramp etc Waveform length 1024 points Sample rate 100MSa s Waveform amplitude resolution 8bits Sinusoidal harmonic rejection gt 240dBc lt 1MHz gt 235dBc 1MHz 20MHz Sine wave total distortion lt 1 20Hz 200kHz Square rise fall edge time lt 35ns Overshoot lt 10 Square wave duty cycle 1 99 6 1 2 Frequency Characteristics Frequency range Sine 40mHz Max frequency MHz Square 40mHz 5MHz Other waveforms 40mHz 1MHz Frequency resolution 40mHz Frequency accuracy 5x10 40mHz Frequency stability 5x10 3 hours
13. 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 variety type of the remote command are shown as followings No blanks in the command Examplel Channel A Single output Sine wave Frequency 1MHz RS232 mode 88SCHA AWAVE 0 No 88 CHA AFREQ 1 MHz Example 2 Channel B Single output Triangle wave Frequency 1kHz RS232 mode 88 CHB BWAVE 2 No 88CHB BTRIG 1 kHz Example 3 Channel A Single Output Pulse wave Duty cycle 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 29 Chapter 5 Optional Parts This chapter introduces the optional parts of the function generator which are not included as 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
14. selection Hz Vrms TTL TTL selection Harmonic wave selection mHz mVrms Utility System setup selection Reset selection s Time Channel Channel selection Attenuation selection ms dB N Other keys Key name Main function others Output On Off Signal output on off Single trigger for sweep and burst function Shift to 2 nd function with other keys Shift t Unit MHz Vpp and exit remote control Key functions 26 keys are available on front panel and a di sound will be heard when pressed Key Menu press key Menu without numeric input users can select all options under the current function Most keys have second functions that are marked in green above the keys To use the second function key Shift should be pressed before pressing the function key A few keys can also be used as unit keys that marked in black below the keys To use the unit function a digit key should be pressed first before the unit key is pressed Key Shift its basic function is for second function shifting Press key Shift the sign t lamp turns on At this time the second function of the function key is validated Press key Shift again the sign 1 lamp turns off At this time the basic function of the function key is validated Key Shift is also used as unit MHz Vpp and has the function for exiting the remote control 4 1 5 Fundamental Operation This section introduces the fundamental operations on the
15. the harmonic time and phase difference so that all kinds of stable Lissajou s figures are generated 3 4 Frequency Sweep Press key Sweep and select Sweep Freq function Sweep Freq is shown on the upper left of LCD 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 interval time manual sweep and auto sweep are free to be set by the users 3 4 1 Set the Start and Stop Frequency The frequency at sweep starting is called start frequency The frequency at sweep ending is called stop frequency Press key Menu and select Start Freq option Input a new start frequency data here by numeric keypad or rotary dial Press the soft key corresponding to the frequency units to confirm the new data input To set the stop frequency press key Menu and select Stop Freq option Input a new stop frequency data here by numeric keypad or rotary dial Note the stop frequency must be greater than 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 step frequency can be determined according to the required accuracy In a sweep process the bigger the step frequency is the less numbers of frequency points and lower accuracy will be the shorter time taken in a sweep process The smaller step fr
16. 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 4 4 1 Enter the Program 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 to tell the instrument back to the manual operation mode Or press key Shift to return to manual operation 4 4 2 Tips for Programming 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
17. 2 Set the Interval Time Press key Menu and select Interval option The interval time value is shown on the LCD display Input a new interval time here by numeric keypad or rotary dial Press the key corresponding to the time units to confirm the new data input 3 9 3 PSK Observation Due to the phase variation 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 signals as synchronization burst signals a stable PSK signal waveform can be observed 3 10 Burst Output of Channel A Press key Burst and select CHA Burst option CHA Burst is displayed in the upper left portion of the LCD The function generator outputs a waveform with a specified number of cycles at the burst frequency continuously at the CHA Output Each set has a preset burst count and there is a time interval between each burst 3 10 1 Set the Carrier Frequency Press key Menu and select Carrier Freq option The carrier frequency value is shown on the LCD display Input a new carrier frequency value here by numeric keypad or rotary dial 3 10 2 Set the Carrier Amplitude Press key Menu and select Carrier Ampl option The carrier amplitude value is shown on the LCD display Input a new carrier amplitude value here by numeric keypad or rotary dial 3 10 3 Set the Burst C
18. HA Duty Cycle ADUTY Single Trigger TRIGG System Reset RESET CHB Frequency BFREQ Single Burst ONCES Phase PHASE CHB Harmonic Wave BHARM FM Deviation DEVIA True RMS VRMS CHB Period BPERD Modulation Waveform MWAVE Language Setup LANG CHB Duty Cycle BDUTY Modulation Frequency MODUF Carrier Amplitude CARRA TTL_A Frequency TTLAF Peak to peak Value VPP Carrier Frequency CARRF TTL_A Duty Cycle TTLAD Beep Sound BEEP Gate Time STROBE TTL_B Frequency TTLBF Interval Time INTVL Stop Amplitude STOPA TTL_B Duty Cycle TTLBD Interface Address ADDR Stop Frequency STOPF TTL_A Trigger TTLTR Sweep Mode MODEL Auto Sweep AUTO Step Amplitude STEPA Start Amplitude STARA Store Parameter STORE Step Frequency STEPF Start Frequency STARF Output Switch SWITCH CHB Waveform BWAVE The Table of Data Command Data String Data String Digit 0123456789 Decimal Point d Negative Sign The Table of 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 TIME Percentage Burst Count CYCL DC Offset Vdc mVdc 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 meaning an end to a data string 4 3 3 Separate Character The separate character has to be placed between the function and option strings between the option and data strings between t
19. Part No FGOM 010010 DDS Function Generator Operation Manual H a gt az Y a a T 3 a A C 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 spare parts for products which are approved defective in this period 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 tradable characteristics and any particular purpose We will not take any responsibility in cases regarding to indirect particular and
20. Single Burst option The function generator turns off the continuous burst mode and signal output is O In the single burst mode press key 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 number is set to 1 the single burst can be operated manually If the Single Burst option is not selected the burst process is back to the continuous burst mode 3 10 6 Set the TTL_A Burst Press key Menu and select TTL_A Burst option At every rise edge of the TTL_A signal the burst process executes once and the function generator outputs one burst waveform according to the preset value of the burst count The burst process executes continuously 3 10 7 Set the External Burst Press key Menu and select External Burst option The Count In terminal is used as trigger signal This function is available only when the user chooses to install the frequency counter Burst count can be used to test the dynamic characteristics of the audio equipment and calibrate the counter 3 11 Burst Output of Channel B Press key Burst and select CHB Burst option CHB Burst is displayed in the upper left portion of the LCD Apply the same definition and setup procedures for all parameters as explained in section CHA Burst 3 11 1 Set the Burst Frequency Press key Menu and select Burst Freq option In
21. a input has more than one decimal point only the first one is valid In the offset mode the negative sign can be input too After input a new value press unit key to validate it If the input data has error there are two ways to correct it Method 1 If the destination side of output signal can receive the wrong signal press any unit key to terminate the current operation Input the correct data and press the unit key to validate the input Method 2 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 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 Different physics value has different unit such as Hz for frequency V for amplitude s for time and for phase However when using numeric keys to enter data the input data will not be effective without the entry of unit The instrument will display the corresponding unit when the physics value is selected 3 1 2 Step Key Input In practices a set of frequency or amplitude value with same interval is commonly used It is complicated and time consuming to input th
22. age If the address matches the instrument starts to receive the following data message until the whole message is received 4 2 8 Data Information After receiving the data message the instrument verifies and stores the data into the memory If the received character is the line feed Chr 10 1t means that this is the end of the data message The instrument starts to execute each operation in this remote command 4 3 Remote Command The remote command is a series of ASCII code strings sent by the host computer The operation of the instrument is based on the remote command Every instrument has its own defined command format In order to control the instrument successfully users have to follow the rules when writing the application program Remote command 1 Remote command 2 without digit and unit Inquiry command CHA AFREOQ 1 31 MHz CHA SQUAR CHA AFREQ Toi ae 10000 1 7 f 1 7 1 5 2 53 54 1 3 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 or the unit string Please refer to the software in the CD ROM attached to the function generator 4 3 1 Command String The instrument remote commands consist of the function string the option string the data string and the un
23. and stability 6 5 Optional Parts Characteristics 6 5 1 Remote Interface RS232 serial interface 6 5 2 Frequency Counter Testing frequency range 1Hz 200MHz Input signal amplitude 100mVpp 20Vpp 6 5 3 Power Amplifier Max output power 7W 8Q 1W 500 Max output voltage 22Vpp Frequency bandwidth 1Hz 200kHz 34
24. annel A signal 3 8 2 Set the Hop Amplitude Press key Menu and select Hop Ampl option Input a new hop amplitude data here by numeric keypad or rotary dial Press the key corresponding to the amplitude units to confirm the new data input The hop amplitude is the second amplitude value of channel A signal There may be a big difference between carrier amplitude and hop amplitude In the ASK process the generator attenuates according to channel A fixed attenuation so as to avoid frequent relay switch during auto attenuation 3 8 3 Set the Interval Time Press key Menu and select Interval option Input a new interval time data here by numeric keypad or rotary dial Press the key corresponding to the time units to confirm the new data input 19 3 9 Phase Shift Keying PSK Press key MOD and select PSK function The upper left portion of the LCD displays A_PSK The function generator outputs the PSK signal on the CHA Output The phase of the output signal is the alternative variation of the reference phase and the hop phase The interval time of alternation is adjustable 3 9 1 Set the Hop Phase Press key Menu and select Hop Phase option Input a new hop phase data here by numeric keypad or rotary dial Press the key that corresponds to to confirm the new data input The hop phase is the second phase value of channel A signal The reference phase is the preset phase value of CHA Alone 3 9
25. 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 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 10 50 60Hz WARNING Connect the protective grounding conductor of the AC power cord to an earth ground to avoid electrical shock 4 Fuse AN 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 Disconnect the power cord before fuse replacement Make sure the cause of fuse blowout is fixed before fuse replacement I 5 Maintenance Inspection Inspect the instrument at regular intervals so that it maintains its initial performance for a long time Check the input power cord for damage of the vinyl cover and overheating of the plug and cord stopper Check the terminal screws and binding posts for loosening
26. ced in section 3 11 1 5 11 CHA CHB Output On Off Press key Channel channel A is shown on the LCD display press Output the output lamp turns to green the signal of channel A outputs Press Output again the output lamp turns off the instrument closes the signal output of channel A Press key Channel channel B is shown on the LCD display press Output the output lamp turns to red the signal of channel B outputs Press Output again the output lamp turns off the instrument closes the signal output of channel B After power on the default state is not having signal output with the lamp being off When the output lamp turns to orange there are signals output both in channel A and channel B 1 5 12 System Initialization Status At power on or pressing keys Shift Reset the system initialization status of the instrument is as the followings CHA CHB waveform sine wave CHA CHB frequency 1 0000000kHz CHA CHB duty cycle 50 0 CHA attenuation AUTO CHB harmonic 1 00 TIME CHA CHB phase 0 Gate time 100ms Start frequency 500 00000Hz Time interval 10ms Carrier frequency 50kHz Sweep mode Up Sweep Modulation frequency 1 0000000kHz FM Deviation 5 Hop frequency 1 0000000kHz Hop phase 180 Burst count 3 CYCL CHA CHB amplitude 2 000Vpp CHA offset 0 000 Vdc Step frequency 10 000000Hz Stop frequency 5 000000kHz Carrier amplitude 2Vpp Modulating waveform sine wave Hop amplitude 1 000Vpp Burst
27. ces 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 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 RS232 interface is the serial asynchronous communication interface which is compliant to EIA RS232 standards It has the characteristics of the long transmission distance and less number of transmission wire Most of
28. cy the displayed frequency data varies with the sweep process simultaneously The setup of other sweep parameters will be introduced in section 3 4 1 5 4 Amplitude Sweep of the Channel A Press key Sweep and select CHA Sw Am The instrument will output the amplitude sweep signal with the default parameters at CHA output Set the interval time set the interval time as 0 5s Press key Menu and select Interval time then press keys 0 5 s Sweep amplitude display Press key Menu and select CHA amplitude the displayed amplitude data varies with the sweep process simultaneously The setup of other sweep parameters will be introduced in section 3 5 1 5 5 Frequency Modulation FM of the Channel A Press key MOD and select FM The instrument will output the FM signal with the default parameters at CHA output Set the FM deviation set the FM deviation as 5 Press key Menu and select FM Deviation then press keys 5 The setup of other FM parameters will be introduced in section 3 6 1 5 6 FSK Modulation of the Channel A Press key MOD and select FSK The instrument will output the FSK signal with the default parameters at CHA output Set the hop frequency set the hop frequency at 1 kHz Press key Menu and select Hop Freq next press keys 1 kHz The setup of other FSK parameters will be introduced in section 3 7 1 5 7 ASK Modulation of the Channel A Press key
29. 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 converter DAC 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 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 9 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 outp
30. e parameter memories starting from index number 0 to 39 Memories of index number 1 39 are available for user defined setting storage except memory of number 0 Memory index number 0 is for the storage of default parameters setup Users also can 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 After input a set of parameters press key Store and select Store option 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 40 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 press key Recall and select Recall option input the recall index 293 number and press the soft key corresponding to No The stored parameter setting is recalled If press key Recall and select Recall option then press key 0 and the soft key corresponding to No the default parameter settings is recalled It can get the same result to press keys Shift Reset 3 14 2 Remote Address Press keys Utility Menu to select Remote Address option The rem
31. e soft key corresponding to to confirm the new data input Deviation 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 100xSHIFT 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 Press key Menu and select Mod Wave option The index number and name of waveform are displayed on the LCD Input the correct index number by numeric keypad or rotary dial to select corresponding waveform Press the key corresponding to No to confirm the index number input The function generator outputs the desired modulated signal 3 6 5 External Modulation 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 s
32. equency is the more numbers of frequency points and higher accuracy will be the longer time taken in a sweep process Press key Menu and select Step Freq option Input a new step frequency data here by numeric keypad or rotary dial Press the soft key corresponding to the frequency units to confirm the new data input 3 4 3 Select the Sweep Mode The frequency sweep has three modes represented by three index numbers 0 1 and 2 Up Sweep 0 Up Sweep the output signal sweeps from the start frequency to the stop frequency at the preset sweep rate Down Sweep 1 Down Swe the output signal sweeps from the stop frequency to the start frequency at the 16 preset sweep rate Up Down Sweep 2 UpDownS the output signal sweeps from the start frequency to the stop frequency at the preset sweep rate then sweeps from the stop frequency to the start frequency at the same sweep rate Press key Menu and select Sweep Mode option The instrument displays the index number and name of the sweep mode User can input the index number or turn the knob to set the sweep mode 3 4 4 Set the Interval Time After the start frequency the stop frequency and the step frequency are set the interval time can be determined according to sweep speed The shorter interval time is the faster sweep speed will be The longer interval time is the slower sweep speed will be However practically the real interval time is the sum of the preset interval
33. general requirements through some examples See Chapter 3 in Operation Manual for more information if you have complex problems or need the complicated operations 1 5 1 Function of Channel A Press key Channel and select CHA Frequency function Set the frequency of the channel A set Frequency as 3 5 kHz Press Freq and select frequency then press keys 3 5 and the soft key corresponding to kHz Adjust the frequency of the channel A press key 4 or P gt to move the cursor left or right and tune the rotary knob left or right to add or subtract the digit on cursor or to decrease or increase the digits continuously by steps so as to make coarse or fine adjustment of the frequency Apply the same procedures for other parameters adjustments Set the period of the channel A set period at 2 5 ms Press key Period and select Period then press keys 2 5 and the soft key corresponding to ms Set the amplitude of the channel A set amplitude at 3 2 Vpp Press key Ampl and select Amplitude then press keys 3 2 and the soft key corresponding to Vpp Set the amplitude format of the channel A Vrms or Vpp Press key Menu to change the format from Vrms to Vpp Press key Ampl to change the format from Vpp to Vrms Select the channel A common waveform select the sine square triangle and ramp wave Press keys Shift to select sine wave Press keys Shift to selec
34. he data and unit strings and between the function string and question mark 4 3 4 Question Mark Adding the question mark before the option string will be return to the corresponding value and unit if no unit the instrument will only return 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 users should firstly send the instrument s address and select the corresponding instrument next send the remote commands 4 3 8 Online Operation First send the interface select command 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 S8LOCAL or press key Shift 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 28 guide before starting to write the application program It is quite easy to program as long as you are familiar with
35. hould 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 amplitude of external modulation signal is the bigger the frequency deviation will be In the external modulation mode the frequency 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 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 18 Press key MOD and select FSK option The upper left portion of the LCD displays A_FSK The function generator outputs the FSK signal on the CHA Output The frequency of the output signal is the alternative variation of the carrier frequency and the hop frequency The interval time of alternation is adjustable 3 7 1 Set the Carrier Frequency Press key Menu and select Carrier Freq option Input a new carrier frequency here by numeric keypad or rotary
36. ich is suitable to frequency testing requiring a short time of stability 3 13 4 Low pass Filter In the measurement of the external signal if the signal frequency is relatively low and has high frequency noise the measured data has bigger error and is not stable Press Menu and select LPF option Use the numeric keypad or rotary dial to change the display to 1 ON and add a 100 kHz low pass filter to the input signal The low pass filter filters out the high frequency noise and makes the measured result much more accurate If the frequency of the testing signal is relatively high the low pass filter may attenuate the signal decrease the sensitivity of the measurement and even result in the wrong testing data In this situation use the numeric keypad or rotary dial to change the display from 1 ON to O OFF and remove the 100 kHz low pass filter For the low frequency of square signal because of steep edge of the signal the trigger error is not significant Therefore the low pass filter is not necessary here 3 14 System Setup Press key Utility to enter system setup mode The system interface is displayed 3 14 1 Store and Recall Parameters 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 The instrument provides 40 index numbers 0 39 for th
37. ime units to confirm the new data input However the instrument still uses the frequency synthesis internally and the input data is just converted to the correct value when it is input and displayed Due to the limitation of the lower resolution at low frequency when the period is too long the function generator can only generate the frequency points with the longer period interval Although the preset and displayed period is precise the actual period of the output signal has the relatively big variation Users shall pay attention to this point 3 2 3 Set the Amplitude of Channel A Press key Ampl and select amplitude of channel A The current amplitude value is displayed Input a new amplitude data here by numeric keypad or rotary dial The function generator outputs the amplitude signal at the CHA Output 3 2 4 Amplitude Format The input and display of the Channel A amplitude value have two formats Vpp and Vrms In RMS format mode press key Menu to switch the format to Vpp In peak to peak format mode press key Ampl to switch the format to Vrms The displayed amplitude value varies with the format conversion simultaneously 12 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 a difference between the format conversions For example if the Vp
38. is displayed as 99 3 2 12 Set the Phase of Channel A Press keys Shift Phase to select Phase option The phase value is shown on the LCD display Input a new phase data here by numeric keypad or rotary dial The phase can be adjusted at any value between 0 360 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 is the lower phase resolution will be For example the frequency is at 1MHz the phase resolution is 3 6 3 2 13 Set the Output Impedance of Channel A Press key Menu and select Impedance option The impedance value is shown on the LCD display The function generator is default as high impedance The impedance value can be set by numeric keypad or rotary dial and the output impedance is 50Q 3 3 Setup of Channel B Press key Channel and select CHB Alone function The upper left area of LCD displays the waveform of channel B signal The channel B settings for frequency period amplitude Vpp and Vrms conversion waveform selection and square duty cycle adjustment are the same as channel A settings But there is not the amplitude attenuation or DC offset functions in channel B 3 3 1 Set the Harmonic Wave 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 of channel A signal P
39. is kind of data by repeatedly pressing the numeric keypad and unit key It is very convenient to use the step input method Every pressing the corresponding soft key can make the frequency or amplitude increase or decrease by a step value The modified data is validated automatically without pressing the unit key For example to generate a series of frequency with interval 12 5 kHz press the keys sequentially as following Press key Menu and select Step Freq Press keys 1 2 5 and the soft key corresponding to kHz Press keys Shift A to increase the frequency by 12 5 kHz or press keys Shift W to decrease the frequency by 12 5 kHz 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 is only used on the frequency and amplitude of channel A 3 1 3 Knob Adjustment In some applications it requires to adjust the output signal continuously Using the rotary knob can complete this task On the top of the displayed parameter there is a triangle shape cursor Press key 4 or P to move the 11 cursor left or right Rotate the knob to the right to continuously increase the cursor located digit by 1 and make the carry to a higher unit position Rotate the knob to the left to continuously decrease the cursor located digit by 1 and make the carry to a lower unit position When you use the knob to modify a
40. it string shown in the tables below Both function and option strings use the uppercase characters Every definition 26 is corresponding to the instrument functionality and option The data string consists of 10 digits from O 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 not be used Otherwise error occurs The Table of Function Command 27 Option String Option String Frequency of Channel A CHA Burst of Channel A ABURST Frequency of Channel B CHB Burst of Channel B BBURST Frequency Sweep of Channel A FSWP FSK of Channel A FSK Amplitude Sweep of Channel A ASWP ASK of Channel A ASK Frequency Modulation of Channel A FM PSK of Channel A PSK External Frequency Measurement COUNT TTL TTL Return to Local LOCAL RS232 control RS232 System SYS The Table of the Option Command Option String Option String Option String CHA Waveform AWAVE Recall Parameter RECAL Hop Amplitude HOPA CHA Offset AOFFS Measuring Frequency MEASF Hop Frequency HOPF CHA Frequency AFREQ Software Version VER Hop Phase HOPP CHA Attenuation AATTE Burst Count NCYCL External Trigger EXTTR CHA Period APERD Burst Frequency BURSF External Modulation EXT C
41. l 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 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 6 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 impedance and the output impedance The output impedance of the instrument is about 50Q When the load impedance is big enough and the voltage dividing ratio is close to 1 the loss on the output load can be ignored The voltage on the load is close to default amplitude value When the load impedance is too small the loss on the output load is significant and can not be ignored The voltage on the output 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 circuit for a few minutes or the transient inverse voltage is less than 30V However this kind of operation should avoid in case of potential damage to the instrument 3 2 7 Amplitude Flatness If the output frequency is lower than 1MH
42. n ncnn can ncnncnno 33 6 3 TIL Output Characters iaa ia its 34 6 4 Common Characteristics aiueo cdo creas dalt daa Ibid degrada dear dad diia dis 34 6 5 Optional Parts AAA TN 34 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 the following 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 you 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 45 VA Temperature 0 40 C Humidity lt 80 Plug the power cord into an 110V 220V 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
43. ote address is displayed and can be modified by numeric keypad or rotary dial 3 14 3 Baud Rate Setup Press keys Utility Menu to select Baud Rate option The RS232 baud rate is displayed and can be modified by numeric keypad or rotary dial 3 14 4 Language Setup Press keys Utility Menu to select Language Setup option The language is displayed Users can select Chinese simplified Chinese traditional English by numeric keypad or rotary dial 3 14 5 Beeper Press keys Utility Menu to select Beep Setup option The Beep On Off is displayed Users can select Beep On Beep Off by numeric keypad or rotary dial 3 14 6 Software Version Press keys Utility Menu to select Software version option The software version is displayed 24 Chapter 4 Programmable Interface This chapter introduces the usage of the programmable 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 equipments have the communication interfa
44. ount Press key Menu and select Cycles option Input a new burst count number here by numeric keypad or rotary dial Press the key corresponding to CYCL to confirm the new data input If the burst frequency is fixed the maximum value of the burst count is limited The lower burst frequency is or we say the longer burst period is the bigger the burst count number can 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 20 3 10 4 Set the Burst Frequency Press key Menu and select Burst Freq option Input a new burst frequency data here by numeric keypad or rotary dial Press the soft key corresponding to the frequency units to confirm the new data input In channel A burst mode TTL_A is used as trigger signal the burst frequency is actually the TTL_A frequency The burst frequency is determined by the Channel A frequency value and the burst count number The multiply of channel A signal period value and burst count number is the time needed for a set of burst In order to keep an appropriate time interval between each burst the burst period should be greater than the time of a burst Otherwise all bursts are connected to each other and the waveform is not the burst signal anymore 3 10 5 Set the Single Burst Mode Press key Menu and select
45. p of sine wave is 1Vpp the Vrms conversion value is 0 353 Vrms If the Vrms of sine wave is 0 353Vrms the Vpp conversion value is 0 998Vpp In most of cases this difference is within the error range The Vrms format can only be used at the CHA Alone mode and the waveform selected as sine wave For other operations and waveforms only peak to peak format can be used 3 2 5 Amplitude Attenuation Press keys Shift Atte to select the attenuation of channel A 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 8 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 Press keys Shift Atte An attenuation data can be input here by numeric keypad or rotary dial There are five ranges of attenuation 008 20dB 40dB 60dB and AUTO which can be input by numeric key 1 2 3 4 and 0 respectively plus the soft key corresponding to dB The attenuation mode can also be selected by rotary dia
46. put a new burst frequency data here by numeric keypad or rotary dial Press the soft key corresponding to the frequency units to confirm the new data input In channel B burst mode TTL_B is used as trigger signal the burst frequency is actually the TTL_B frequency The burst frequency is determined by the Channel B frequency value and the burst count number The multiply of channel B signal period value and burst count number is the time needed for a set of burst In order to keep an appropriate time interval between each burst the burst period should be greater than the time of a burst Otherwise all bursts are connected each other and the waveform is not the burst signal anymore 21 3 11 2 Set the TTL_B Burst Press key Menu and select T TL_B Burst option At every rise edge of the TTL_B signal the burst process executes once and the function generator outputs one burst waveform according to the preset value of the burst count The burst process executes continuously 3 12 TTL Press TTL and select TTL option TTL is displayed in the upper left portion of LCD The generator outputs the corresponding TTL signal at TTL_A and TTL_B terminal on the rear panel 3 12 1 Set the TTL_A Frequency Press key Menu and select TTL_A Freq option The TTL_A frequency value is shown on the LCD Input a new TTL_A frequency value by numeric keypad or rotary dial 3 12 2 Set the TTL_A Duty Cycle Press key Menu and select
47. quency Testing optional frequency counter capable of external frequency signal testing O Power Amplifier optional part maximum output power up to 7W O Remote Control optional RS232 interface Check List Optional Parts DDS function generator 1 O Operation manual 1 O RS232 interface Power cord 1 e RS232 software CD optional 1 Frequency counter O Q9 test lead 1 RS232 cable optional 1 Power amplifier e Q9 BNC clip test lead 1 IV Contents Safety INSTUCHON erua cesses secede eE E E E EE Ita diria iia aid dida in des highs eE E ERE EN e I NN IV Chapter Quick Statistical diodo rai dead EA TENE ES DEERE 1 LA Preparar a AE A A a EA eraubeducds wes 1 1 2Front and Rear Padel A AA AS 2 1 3 Description of LED Display iia ad tad ascitis ad 3 1 4 Key DescriptiOniss iii a LA A a Ad ASENA ONA 4 115 Fundamental Opera ss E EE E ENEE AEE EATE Ea A vesvaddevevedideveasstatves Sits 5 Chapter 2 Principle of the Function Generator ssesessessersseetseststeststerestsestsreststesrstertsteenterestneesrsestneesrneserstesent 9 A A EN 9 2 2 Principle of Direct Digital Synthesis variacion dai 9 2 3 Principle oft Operation and Control Rida 10 Chapter 3 Operav on INStUCUOM rra Anas 11 3 1 Operation Common Rules nasosini anoeie cd dsc 11 3 2 Setup of Channel Ajuda AA Adidas 12 3 3 Setup OL Channel BA a tio 15 FA Frequency SWEEP isc A A AA AAA epe ae 16 NN A e a e aa E eE E ie eaen aaa ae 17 3 6 F
48. requency Modulati n FM nai aida 17 3 7 Frequency Shift Keyme ES iii td da 18 3 8 Amplitude Shift Keying ASK coconoccccnocconnnoncnncononnnonncnnonncnnonncnnonnnonnonncnn cnn nonncnnc nacen non ncnn cana rn nana nnnanncnn ns 19 39 Phase SME Keying PSK AA O 20 3 10 Burst Output of Channel Aina di ia ica 20 3 11 Burst Output of Channel Bi ida did 21 A A NA 22 3 13 Meas re External Frequency c ieclitsscdicdeseenssdbeleds susseeesbauebadb scgnesseensodussudescontdesedvbestbsdebeaeedvecntaaets evan 22 SLA System Setup acatar da dada dada iaa 23 Chapter 4 Programmable Interface AAN dactavarstonvosbutducgaye 25 A i Interface Appl at OM econo dae cilindrada ves E nese tos a A a E E N n 25 ADRSZI ZINC ii suse ced dostuds A A A A A ad 25 4 3 Remote Commang iia a AAA A AA ad 26 A A Application dd c a 28 Chapter 3 Optional Parts vecinita tera aabt adria oot 30 IL Frequency Counter issii eiiiai du dobe duo deniecgo o den buscada tupac dep danna tasado debs Ueseeuledunnsdbaceasesseenssints 30 5 2 Power Amplio io AAE A E EA ia oi aa Ia 30 DIRS Zi Ln A Ea abba vats eee ete 31 Chapter 6 Technical Specifications rsen a e a aE Ni Seia SOSE anaa a OAS aa 32 6 1 Output Characteristics of Channel As ocnieieru sociis aioin eii ere eisini iison esin iaioa 32 6 2 Output Characteristics of Channel B oococcnncniccncconnnncononnnonnconcnnconncnncnnonn conc cnnonnonn conc cnncnn on no
49. requency and amplitude apply the same setting method as explained in section 1 5 1 Select the channel B common waveform select the sine square triangle and ramp wave Press keys Shift to select sine wave Press keys Shift to select square wave Press keys Shift to select triangle wave Press keys Shift v to select ramp wave Select the channel B other waveform select exponent wave same as channel A waveform index number is 16 For details please refer to the table of the waveform index number and name in section 3 2 10 Press keys Shift Arb then press keys 1 6 and the soft key corresponding to No Set the channel B harmonic wave set the frequency of channel B as a 3 time harmonic wave of channel A Press keys Shift Harmonic 3 TIME Set the phase of channel A and channel B set the phase of channel A and channel B as 45 and 90 respectively Press key Channel and select channel A then press keys Shift Phase 4 5 Press key Channel and select channel B then press keys Shift Phase 9 0 1 5 3 Frequency Sweep of the Channel A Press key Sweep and select Sweep Freq function The instrument will output the frequency sweep signal with the default parameters at CHA output Set the sweep mode set the Up Down sweep mode Press key Menu and select Sweep mode then press keys 2 No Sweep frequency display Press key Menu and select CHA frequen
50. ress keys Shift Harmonic to select CHB Harmonic Input harmonic times via numeric keypad or rotary dial Press the soft key corresponding to TIME to confirm the new data input Channel B frequency becomes the 15 set multiple times of channel A frequency That means channel B signal becomes the multiple N times harmonic of channel 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 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 CHB Harmonic and set harmonic time so that channel B frequency can change automatically 3 3 2 Set the Phase of Channel B If CHB Harmonic is set press keys Shift Phase to select CHB Phase At this time the CHA and CHB signals have full synchronization and the phase difference is O Input a new phase data by numeric keypad or rotary dial When the frequency is at low value the phase has a high resolution For example the frequency is below 27kHz the phase resolution is 1 The higher frequency is the lower phase resolution will be For example the frequency is at 1MHz the phase resolutions is 36 Connect the channel A and B signals to an oscilloscope set
51. ristics Waveform type 32 waveforms including Sine Square Triangle Ramp etc Waveform length 1024 points Sample 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 Frequency resolution 10mHz Frequency accuracy 1x1 0 10mHz 6 2 3 Amplitude Characteristics Amplitude range 50m Vpp 20V pp 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 33 6 3 TTL Output Characteristics Waveform characteristics Square rise fall time lt 20ns Frequency characteristics 10mHz 1MHz Amplitude characteristics TTL CMOS compatible low level lt 0 3V high level gt 4V 6 4 Common Characteristics 6 4 1 Power Source Voltage AC220V 1410 AC110V 1 10 Pay attention to the position of voltage selection switch Frequency 50Hz 1 5 Power lt 45VA 6 4 2 Environment Temperature 0 40 C Humidity lt 80 6 4 3 Operation Characteristics Keypad operation and rotary knob operation 6 4 4 Display LCD display English Chinese simplified Chinese traditional 6 4 5 Dimension and Weight Chassis dimensions 415mmx295mmx195mm Weight 3 5kg 6 4 6 Manufacturing Technology Surface Mount Technology Integrated Circuit High reliability
52. specified data the modified data is validated instantaneously without pressing the unit key A coarse adjustment is made by moving the cursor to the left and a fine adjustment is made by moving the cursor to the right 3 1 4 Input Mode Selection It is convenient to input the known data through the numeric keypad It makes the input 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 rotary knob is usually more useful For a series of equal interval data input the step input method is the most efficient Users can use the different data input methods according to different situations 3 2 Setup of Channel A Press key Channel and select CHA Alone function The upper left area of LCD displays the waveform of channel A signal 3 2 1 Set the Frequency of Channel A Press key Freq to display the current frequency Input a new frequency data here by numeric keypad or rotary dial Press the key corresponding to the frequency units to confirm the new data input The function generator outputs the specified frequency at CHA Output 3 2 2 Set the Period of Channel A The frequency of the channel A can also be set and displayed in the way of period Press key Period to display the current period Input a new period data here by numeric keypad or rotary dial Press the key corresponding to the period t
53. t Measurement Press key Menu and select Measure Freq option Connect the external signal to the Count In terminal on the rear panel The instrument displays the frequency of measured external signal The measured external signal can 22 be periodical 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 checks 3 13 3 Set the Gate Time Press key Menu and select Gate Time option Input a new gate time data here by numeric keypad or rotary dial Press the key corresponding to the time units to confirm the new data input 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 is the more cycle numbers to be collected from the testing signal the more stable the average value will be the more valid digits to get in testing results but the slower tracking to the frequency variation will be which is suitable to frequency testing requiring a long time of stability The shorter gate time is the less valid digits to get in testing results the faster tracking to the frequency variation will be wh
54. t square wave Press keys Shift to select triangle wave Press keys Shift V to select ramp wave Select the channel A other waveform select exponent wave waveform index number is 16 For details please refer to the table of the waveform index number and name in section 3 2 10 Press keys Shift Arb then press keys 1 6 and the soft key corresponding to No Set the channel A duty cycle set the duty cycle at 65 Press keys Shift Duty then press keys 6 5 and the soft key corresponding to Set the channel A attenuation select the fixed attenuation OdB after power on or reset the instrument is default as AUTO attenuation Press keys Shift Atte then press key 1 and the soft key corresponding to dB Set the channel A offset in the attenuation 0dB mode set DC offset as 1 Vdc Press key Offset and select Offset then press keys 1 and the soft key corresponding to Vdc Set the channel A step frequency set the step frequency at 12 5 Hz Press key Menu and select Step Freq Press keys 1 2 5 and the soft key corresponding to Hz Press key Menu and select channel A frequency Press keys Shift A the frequency increases 12 5 Hz Press keys Shift V the frequency decreases 12 5 Hz Apply the same setting procedures for CHA amplitude step settings 1 5 2 Function of Channel B Press key Channel and select CHB Frequency function Set the channel B f
55. the current computer has the RS232 interface Recently RS232 interface is gradually being replaced by USB interface because of its low transmission rate and inconvenient connection 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 eleven bits 1 start bit logic 0 8 data bits ASCII code 1 index bit address logic 1 data logic 0 1 stop bit logic 1 4 2 3 Transmission Rate In this instrument the transmission rate is set to 19200 bits s and can be reset in the software 25 4 2 4 RS232 Interface Connection Connect the RS232 connector on the rear panel to the COM1 or COM2 connector on the computer with a RS232 cable 4 2 5 System Construction In one system the maximum number of connected instruments is 99 and the total length of connection cable cannot exceed 100 meters 4 2 6 Applications 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 whether the received address matches its own address or not if not ignore all following messages and wait for the next address mess
56. three hole power cord with protective earth ground has to be used 1 2 Front and Rear Panel Front panel N rl Nn Se Arb A y 1 2 3 CHA Amol Sweep MOD Menu 4 1 A m A Duty Phase Harmonic Reset Atte Output ea am ON m OFF shift Buret Counter TTL 238 Olo MHz Vpp kHz mVpp 1 LCD display 2 Power switch 3 Keypad 4 Channel B output 5 Channel A output 6 Rotary knob Rear Panel Ol STIL Out hair pb pedal li THE COVER UNLESS BY SPECIFIED PERSONNEL OO Eo OO RS 232 65W Max 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 On the top line of the LCD display the function and operation option are displayed In the CHA Alone and CHB Alone mode the current function or the output waveform is shown on the left side and the current option is shown on the right side Under each function there are variety options shown in the table below The options with shadow are frequently used which can be selected by using the shortcut function keys on the front panel However the options without shadow are not common So first select the corresponding function then use the key Menu to select them At the bottom line of the LCD display the parameters of the current option are displayed The table of function and option
57. 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 Press key Menu and select Interval option Input a new interval time here by numeric keypad or rotary dial Press the soft key corresponding to the time units to confirm the new data input 3 4 5 Manual Sweep Select Manual Sweep option press key Trigger once the sweep process goes on by one step The output frequency increases or decreases by one step frequency value 3 4 6 AUTO Sweep The output frequency automatically increases or decreases by one step frequency value in a certain interval time 3 5 Amplitude Sweep Press key Sweep and select Sweep Ampl function Sweep Ampl is shown on the upper left of LCD The function generator outputs the amplitude sweep signal at the CHA Output All operations of sweep parameter sweep mode manual sweep and auto sweep apply the same operation procedures as explained in section Channel A frequency sweep To make sure of the continuous variation of output signal amplitude the channel A attenuation value should be set first in CHA Alone function Additionally in amplitude sweep process the generator should attenuate according to the channel A fixed attenuation so as to avoid frequent relay switch during auto attenuation 3 6 Frequency Modulation FM Press key
58. tude e High Frequency Resolution full range resolution is 40 mHz O No Range Limitation no frequency level switch frequency set directly by digit keypad O No Frequency Transition momentarily switch to the stable value on phase and amplitude without transition and distortion O Precise Output Waveform output waveform is synthesized by the preset function calculation values very accurate and less distortion e Multiple Waveforms output 32 kinds of the pre stored waveforms Pulse Characteristics set accurate pulse duty cycle Output Characteristics two independent output channel precisely set the phase of the two channel Frequency Sweep frequency sweep function free to set the start and stop points O Amplitude Sweep amplitude sweep function free to set the start and stop points O Frequency Modulation 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 English Chinese menu selectable parameters settings by numeric keypad or rotary dial High Reliability use VLSI components and surface mount technology O Protection over voltage protection over current protection output short circuit protection reverse voltage protection O Fre
59. ut 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 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 10 Chapter 3 Operation Instruction In this chapter you will learn more information about the functions and operations 3 1 Operation Common Rules 3 1 1 Numeric Keypad Input If an option is selected you can input the parameters by using the numeric keys There are ten numeric keys for data input The input method is the shift input from left to right The data can have only one decimal point If one dat
60. wave Press keys Shift v to select ramp wave The function generator outputs the selected waveform at the CHA Output For 4 frequently used waveforms they are displayed as waveform name in the upper left portion of the LCD As to the other 28 waveforms which are not frequently used they are displayed as Arb in the upper left portion of the LCD The index number and name of the 32 waveform are shown as the table below The Index Number and Waveform Name of Channel B Index Number Name Index Number Name 00 Sine 16 Exponent 01 Square 17 Logarithm 02 Triang 18 Half round 03 Up ramp 19 Tangent 14 04 Down ramp 20 Sin x x 05 Pos pulse 21 Noise 06 Neg pulse 22 Duty 10 07 Tri pulse 23 Duty 90 08 Up stair 24 Down stair 09 Pos DC 25 Po bipulse 10 Neg DC 26 Ne bipulse 11 All sine 27 Trapezia 12 Half sine 28 Coscine 13 Limit sine 29 Bidir SCR 14 Gate sine 30 Cardiogram 15 Square root 31 Earthquake 3 2 11 Set the Square Duty Cycle of Channel A Press keys Shift Duty to select square wave The square duty cycle is shown on the LCD display A new duty cycle data can be input here by numeric keypad or rotary dial The duty cycle value can be set at any value between 1 99 When the converted duty cycle value is less than 1 the duty cycle value is displayed as 1 When the converted duty cycle value is greater than 99 the duty cycle value
61. ys on the front panel The black word on each key represents the basic function Simply press the key to use the basic function The green word at the upper of key represents the second function of the key Press key Shift the sign t will be displayed at the lower right of the LCD Then press the function key you can select the second function In this section the basic functions of the 26 keys will be introduced The second function of the 14 keys will be introduced in the following chapters Numeric keys Key name Main function Second function Key name Main function Second function 0 Input digit O 7 Input digit 7 A 1 Input digit 1 gt 8 Input digit 8 2 Input digit 2 a 9 Input digit 9 TE 3 Input digit 3 Input decimal point 4 Input digit 4 ORG i Input negative sign 5 Input digit 5 Flash digit left shift Add digit 6 Input digit 6 gt gt Flash digit right shift Subtract digit Function keys Key name Main function Second function Unit function Freq Period Frequency period selection Sine selection Ampl Offset Amplitude offset selection Square selection gt Sweep Sweep selection Triangle selection MOD Modulation selection Ramp selection Menu Menu selection Waveform selection Burst Burst selection Duty cycle selection kHz mVpp Counter Frequency counter selection Phase
62. z 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 amplitude and frequency characteristics of the output signal will not be so good The maximum output amplitude is also affected The higher frequency is the higher amplitude and the more distortion will be in output waveform 13 Output frequency 10MHz 15MHz max output amplitude 15Vpp Output frequency 15MHz 20MHz max output amplitude 8Vpp 3 2 8 Set the Offset of Channel A Press key Offset and select CHA Offset The current offset value is shown on the LCD display Input a new offset data here by numeric keypad or rotary dial Press the key corresponding to the offset units to confirm the new data input 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 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

User manual

Contents

Download Pdf Manuals

Related Search

Related Contents