Fluke DDS Function Generator 271 User's Manual
Contents
1. Q Mains supply OFF Mains supply ON Alternating current N A Warning hazardous voltages may be present iii EMC Compliance This instrument meets the requirements of the EMC Directive 89 336 EEC Compliance was demonstrated by meeting the test limits of the following standards Emissions EN61326 1998 EMC product standard for Electrical Equipment for Measurement Control and Laboratory Use Test limits used were a Radiated Class B b Conducted Class B c Harmonics EN61000 3 2 2000 Class A The instrument is Class A by product category Immunity EN61326 1998 EMC product standard for Electrical Equipment for Measurement Control and Laboratory Use Test meth ods limits and performance achieved were a EN61000 4 2 1995 Electrostatic Discharge 4 kV air 4 kV contact Performance A b EN61000 4 3 1997 Electromagnetic Field 3 V m 80 AM at 1 kHz Performance A c EN61000 4 11 1994 Voltage Interrupt 1 cycle 100 96 Performance A d 61000 4 4 1995 Fast Transient 1 kV peak ac line 0 5 kV peak signal lines and RS232 GPIB ports Performance A 271 Getting Started Manual e EN61000 4 5 1995 Surge 0 5 kV line to line 1 kV line to ground Performance A f EN61000 4 6 1996 Conducted RF V 80 AM at 1kHz ac line only signal connections 3 m not tested Performance A According to EN61326 the definitions of performance criteria are Performance criterion A During test normal2. This 2 octave range is well within the limits of audibility so you can listen on headphones if you wish Set the amplitude to about 10 dBm or you may be surprised by the intensity The description logarithmic means that the sweep spends an equal period at each note of the scale and is a misnomer because the rate of frequency increase with time is in fact exponential The set up process is as follows Press RECALL 0 ENTER to reset to the factory defaults Then press EDIT and SWEEP At this point the lamp next to the SWEEP key should be flashing and the display should look like this MODE BEG END LAW LOG RAMP TIME 0 05 s TRIG SRC CONTINUOUS MORE gt gt gt All these settings are fine except for the sweep time which is too short if you are listening to the signal Change the sweep time to say 5 seconds When you press the ENTER key the display will return to the main menu so press EDIT and SWEEP again and use the FIELD key to move to the next screen MODE BEG END LAW LOG RAMP TIME 5 00 s TRIG SRC CONTINUOUS MORE gt gt gt Now set the beginning and end frequencies The frequencies shown here correspond to a sweep of 2 octaves starting at middle C with a marker in the middle of the sweep Getting Started Using the Instrument BEG FRQ 261 6000 Hz END FRQ 1 108700kHz MARK FRQ 523 3000 Hz MORE gt gt gt Now press the SWEEP key The sweep is generated continuously You can reverse
3. Users Manual SYNC OUT This socket is used when SYNC OUT the instrument is the master in a master slave set up It provides a signal to drive the EXT TRIG front panel input of the slaved instrument shx0014f gif Master slave operation is beyond the scope of this Getting Started Manual but is covered in chapters 12 and 13 of the Users Manual 271 Getting Started Manual TRIG SWEEP OUT The TRIG SWEEP output Socket provides both trigger and marker signals depending on the instrument s mode of operation shx0016f gif Its primary use is for triggering an oscilloscope or other recording device but it can also provide z axis bright up markers during sweep and frequency hopping modes 10 RS232 and GPIB Interface Connectors These sockets are for controlling the instrument remotely using a PC or other controller device Remote control is beyond the scope of this Getting Started Manual but is covered in detail in chapter 16 of the Users Manual shx00171 gif GPIB Using the Instrument While familiarizing yourself with the instrument you will find it useful to observe the outputs on an oscilloscope For most purposes it is sufficient to connect the MAIN OUT front panel socket to the oscilloscope s Y input and the AUX OUT front panel socket to the oscilloscope s trigger input If no oscilloscope is available you can still learn a great deal about the instrument settings since the effect of
4. reserves the right to invoice Buyer for importation costs of repair replacement parts when product purchased in one country is sub mitted for repair in another country Fluke s warranty obligation is limited at Fluke s option to refund of the purchase price free of charge repair or replacement of a defective product which is returned to a Fluke authorized service center within the warranty period To obtain warranty service contact your nearest Fluke authorized service center to obtain return authorization information then send the product to that service center with a description of the difficulty postage and insurance prepaid FOB Destination Fluke assumes no risk for damage in transit Following warranty repair the product will be returned to Buyer transportation prepaid FOB Destination If Fluke determines that failure was caused by neglect misuse contami nation alteration accident or abnormal condition of operation or handling including overvoltage failures caused by use outside the product s specified rating or normal wear and tear of mechanical components Fluke will provide an estimate of repair costs and obtain authorization before commencing the work Following repair the product will be returned to the Buyer transportation prepaid and the Buyer will be billed for the repair and return transportation charges FOB Shipping Point THIS WARRANTY IS BUYER S SOLE AND EXCLUSIVE REMEDY AND IS IN LIEU OF ALL OTHER WARRANTIES EXPRE
5. screens for HOP mode press EDIT then the numeric 5 key MODE TRIG GATE LI LI FSK AM 1 1 STAIR ARB de 1 To return to the main menu Cle 27 A from any edit menu press T the ESCAPE key shx0010f gif Getting Started Controls and Connections UTILITIES Keys The UTILITIES keys give access to the STORE RECALL and REMOTE edit menus The instrument can store up to nine set ups numbered 1 to 9 and can recall any of those plus set up 0 which is the factory default set up and is not editable UTILITIES RECALL Shx0011f gif The MAN SYNC key is used for manual triggering and synchronizing two or more generators when suitably connected together Further information on synchronizing two generators is given in the Users Manual OUTPUT Key The OUTPUT key turns the MAIN OUT on and off on OUTPUT When the output is on the 9 LED next to the key is lit The default state at power up is with the output off shx0018f gif 271 Getting Started Manual Front Panel Inputs and Outputs MAIN OUT MAIN OUT is the 50 Q or 600 output from the main generator It will provide up to 20 V p p into a high impedance load or 10 V p p into a matched 50 or 600 load It can tolerate a short circuit for 60 seconds AUX OUT The AUX OUT socket provides a two level TTL and CMOS compatible signal synchronous with the signal from the MAIN OUT
6. socket MAIN E d shx0005f gif shx0006f gif The symmetry of the AUX OUT signal is the same as that set for the main output but you can adjust the phase relationship between MAIN OUT and AUX OUT using the PHASE setting in the TRIG menu AUX OUT logic levels are nominally 0 V and 5 V from typically 50 O AUX OUT will withstand a short circuit EXT TRIG EXT TRIG is the external trigger input for the non continuous modes trigger gate sweep FSK and hop and for synchronizing the generator as a slave to an external master generator Getting Started Controls and Connections Rear Panel Connectors CLOCK IN OUT This socket operates both as an input and as an output depending on the mode in which the instrument is being used shx0013f gif As an input it can be used either to run the instrument from an external master clock or as a synchronization input when slaved to another instrument as the master As an output it provides the internal master clock or the master synchronization output for another instrument as the slave In both modes the levels are TTL and CMOS compatible VCA IN This is the modulation input for voltage controlled amplitude 2 5 V will drive the amplitude to 100 of its programmed value The input impedance is approximately 6 shx0013f gif Modulation is beyond the scope of this Getting Started Manual but is covered in detail in chapter 8 of the
7. still display the rms values but the dBm representation is excluded from the list 271 Getting Started Manual Numeric Units and SET Keys You can use these keys to enter parameter values directly For example to set the period to 125 us select the first field FREQ THORNE Hz ms dBm change it to period PER OOO by pressing DIGIT key then enter 1 2 5 us on the keypad kHz us mV Ooo mHz s Ooo shx0009f gif If the numeric value is dimensionless for example a BURST COUNT the ENTER key terminates the entry otherwise it is terminated by the units key If you are editing one of the parameters in the main FREQ PER menu frequency period amplitude dc offset or symmetry you can use one of the SET keys to navigate to the appropriate field directly shx0007f gif The CE key clears the entry one key press at a time The ESCAPE key abandons the current editing action 6 In addition if the display is of any menu other than the main menu the ESCAPE key will return you to the main menu MODE Keys Alternate presses of a MODE key will turn the mode TRIG GATE AM etc on or off and when the function is on the associated lamp is lit If you press the EDIT key then press a MODE key you will see the edit menu for that mode The associated lamp flashes when the edit menu is displayed Some of the modes share keys with the numeric keypad For example to see the edit
8. the direction on the first sweep edit menu by changing MODE BEG END to MODE END BEG You can also set up to initiate the sweep manually do this by changing TRIG SRC CONTINUOUS to TRIG SRC MAN REMOTE Single sweeps are now initiated by pressing the MAN SYNC key Note that the settings for the internal trigger generator have no bearing on the sweep in this instance 17 271 Getting Started Manual Generating a Triggered Burst In this exercise you will use the internal trigger generator to initiate a burst of 500 cycles of a 2 kHz tone twice every second The period of the internal trigger generator is thus 500 ms Press RECALL 0 ENTER to reset to the factory defaults Then press EDIT and TRIG The lamp next to the TRIG key should flash and the display should show SOURCE EXT TGEN 1 00ms 1 000kHz BURST COUNT 0001 PHASE 000 000 Change the settings to SOURCE TGEN FREE TGEN 500 ms 2 000 Hz BURST COUNT 0500 PHASE 000 000 The word FREE against the SOURCE parameter indicates that the internal trigger generator has not already 18 been assigned to some other function If it had been that function would be shown in place of the word FREE Press ENTER turn the output on and set the frequency on the main menu to 2 kHz which at that point will be a continuous tone FREQ 2 000000kHz VhiZ 20 0 Vpp 500 DC 0 00mV 0 00mvV SYM 50 0 50 0 Press TRIG to initiate the triggered bur
9. the right of the programmed dc offset is the value which results from the application of 20 dB of attenuation It may differ slightly from the calculated value 150 mV because of the attenuator s saved calibration factors Asymmetric waveforms Symmetry adjustments work in much the same way as dc offset adjustments However because of the lengthy calculations which the instrument makes following a change to the symmetry setting you may find it easier to use direct numeric entry rather than the rotary control Again the symmetry of the output is displayed in brackets at the right of the programmed value and in certain circumstances the programmed and actual values may differ For example at high output frequencies the specification limits for symmetry are 20 to 80 for a square wave but 1 to 99 96 for a sine wave Full details are given in the Specifications section in chapter 1 of the Users Manual Adjusting the phase The AUX OUT socket supplies a TTL and CMOS compatible 0 4 V reference signal against which you can adjust the phase of the signal at the MAIN OUT Socket Return to the factory default settings by pressing RECALL 0 ENTER then press the EDIT key followed by TRIG Getting Started Using the Instrument The lamp next to the TRIG key will flash and you should see a screen like this SOURCE EXT TGEN 1 00ms 1 000kHz BURST COUNT 0001 PHASE 000 4000 The instrument is still operating in continuou
10. FLLIKE 271 Programmable 10 MHz DDS Function Generator Getting Started Manual PN 2423297 January 2005 2005 Fluke Corporation All rights reserved Printed in USA All product names are trademarks of their respective companies LIMITED WARRANTY AND LIMITATION OF LIABILITY Each Fluke product is warranted to be free from defects in material and workmanship under normal use and service The warranty period is one year and begins on the date of shipment Parts product repairs and services are warranted for 90 days This warranty extends only to the original buyer or end user customer of a Fluke authorized reseller and does not apply to fuses disposable batteries or to any product which in Fluke s opinion has been misused altered neglected contaminated or damaged by accident or abnormal conditions of operation or handling Fluke warrants that software will operate substantially in accordance with its functional specifications for 90 days and that it has been properly recorded on non defective media Fluke does not warrant that software will be error free or operate without interruption Fluke authorized resellers shall extend this warranty on new and unused products to end user customers only but have no authority to extend a greater or differ ent warranty on behalf of Fluke Warranty support is available only if product is purchased through a Fluke authorized sales outlet or Buyer has paid the applica ble international price Fluke
11. SS OR IMPLIED INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE FLUKE SHALL NOT BE LIABLE FOR ANY SPECIAL INDIRECT INCIDENTAL OR CONSEQUENTIAL DAMAGES OR LOSSES INCLUDING LOSS OF DATA ARISING FROM ANY CAUSE OR THEORY Since some countries or states do not allow limitation of the term of an implied warranty or exclusion or limitation of incidental or consequential damages the limitations and exclusions of this warranty may not apply to every buyer If any provision of this Warranty is held invalid or unenforceable by a court or other decision maker of competent jurisdiction such holding will not affect the validity or enforceability of any other provision Fluke Corporation Fluke Europe B V P O Box 9090 P O Box 1186 Everett WA 98206 9090 5602 BD Eindhoven U S A The Netherlands 11 99 To register your product online visit register fluke com Safety This function generator is a Safety Class instrument according to IEC classification and has been designed to meet the re quirements of EN61010 1 Safety Requirements for Electrical Equipment for Measurement Control and Laboratory Use It is an Installation Category Il instrument intended for operation from a normal single phase supply This instrument has been tested in accordance with EN61010 1 and has been supplied in a safe condition This Getting Started Manual contains some information and warnings which must be followed b
12. adjust the display contrast using a small screwdriver or trimmer tool inserted in the hole marked LCD At power up the instrument goes through a self test cycle and the display shows the firmware revision number for a few seconds If any tests fail the display will show a message indicating the nature of the fault if this happens refer to the Users Manual The display shown above is called the main menu and shows the frequency or period amplitude dc offset and symmetry of the waveform Other menus called edit menus are called when you press the EDIT key followed by a MODE key If the main menu display is not as shown in figure 1 above then you should reset all settings to their factory defaults Do this by pressing RECALL then the numeric 0 key then ENTER Controls Function Keys These three keys are used to choose between the basic waveforms sine square and triangular FUNCTION O SQUARE waves and pulses and O Puse ramps of either polarity O TRIANGLE O RAMP shx0008f gif Repeated presses of a key will cycle the selection through the two or three choices offered The associated LED will light FIELD and DIGIT Keys and the Rotary Control The FIELD keys move the display cursor between 4 fields L lt FIELD DIGIT gt The fields in the display shown in figure 1 above Too are FREQ 10 00000 Shx0004f gif kHz Vhiz and so on Each field is one of three types a p
13. arameter name a parameter value or a unit name The DIGIT keys work in different ways depending on selected field type When the field contains a numeric parameter value the DIGIT keys move the cursor right less significant or left more significant The rotary control will then increment or decrement the digit indicated When the field contains a unit name the DIGIT keys have the effect of multiplying or dividing the value by 10 they simultaneously set the display of the value and its unit in the most convenient engineering format The rotary control has the same effect Getting Started Controls and Connections Thus for example if you select kHz with the FIELD key successive presses of the right DIGIT key or rotating the knob clockwise change the value and the units as follows 10 00000kHz 100 0000kHz 1 000000MHz 10 00000MHz When the field contains a parameter name successive presses of the DIGIT keys allow you to make a selection from all the possible choices for that parameter Again the rotary control has the same effect For example with VhiZ selected in the start up screen above successive presses of the right DIGIT key or rotating the knob clockwise change the amplitude displayed as follows VhiZ 20 0 Vpp VhiZ 7 07 Vrms 10 0 Vpp 3 54 Vrms QUT 24 0dBm V V All of these are equivalent representations of the output amplitude for a sine wave If the waveform is not sinusoidal then you can
14. e and if inevitable shall be carried out only by a skilled person who is aware of the haz ard involved e Make sure that only fuses with the required rated current and of the specified type are used for re placement The use of makeshift fuses and the short circuiting of fuse holders is prohibited A Caution If the instrument is clearly defective has been subject to mechanical damage excessive moisture or chemical corrosion the safety protection may be impaired and the apparatus should be withdrawn from use and returned for checking and repair Note 85 This instrument uses a Lithium button cell for non volatile memory battery back up Typical battery life is 5 years In the event of replacement becoming necessary replace only with a cell of the correct type a V Li Mn02 20 mm button cell type 2032 Do not mix with solid waste stream Do not cut open incinerate expose to temperatures above 60 or attempt to recharge Used batteries should be disposed of by a qualified recycler or hazardous ma terials handler Contact your authorized Fluke Service Center for recycling information A Caution Do not wet the instrument when cleaning it and in particular use only a soft dry cloth to clean the LCD win dow Safety continued The following symbols are used on the instrument and in this manual A Caution refer to the accompanying documentation incorrect operation may damage the instrument d Terminal connected to chassis ground
15. eform with up to 16 steps To demonstrate the set up process we will create a signal that approximates a 625 line PAL TV line signal This is the signal applied to the Z axis of the TV s CRT to modulate the brightness of the spot The refresh rate in PAL TV is 25 Hz 40 ms and the screen is rasterized into 625 lines Thus each line takes 64 us and the line frequency is the inverse of this 15 625 kHz By definition the black level called the blanking level because it cuts off the electron beam completely is 30 of peak amplitude and the white level is 100 These levels usually correspond to 0 3 V and 1 0 V respectively The line sync pulse is negative going and takes the level down to 0 It is nominally 4 7 us wide and it occurs in the first few microseconds of the cycle just before a region called the back porch which precedes the scan The horizontal scan runs from 12 05 to 63 70 us outside this period the CRT is blanked To produce an image on the TV screen we will divide the scan period into five approximately equal segments and 19 271 Getting Started Manual set the levels to produce five monochrome stripes from left Our line signal thus looks like the drawing below to right grey white grey black and grey again 100 65 Blanking level black Back porch Sync level A 0 18 65 124 224 32 8 43 1 53 4 63 7 64 0 us shx0019f gif Figure 2 625 line PAL TV Sig
16. front panel operations is visible in the LCD display in the form of text messages parameter information menus and status information Getting Started Using the Instrument Starting up The ac supply on off switch is located at the bottom left side of the front panel Caution Before connecting to the ac supply check that the supply voltage setting is correct for the region Please refer to the Users Manual if it needs to be changed Plug in and switch on the instrument On power up the LCD panel illuminates and the instrument performs a series of self tests In the event that an error message is displayed please refer to the Users Manual Check the LCD Display It should look similar to the main menu shown in figure 1 If not press RECALL 0 ENTER to bring up the factory default main menu 11 271 Getting Started Manual Generating Continuous Signals Select SINE on the function keys if it is not already selected If there is no signal at the oscilloscope input it will almost certainly be because the generator s output is switched off If the lamp next to the MAIN OUT socket is not lit press the OUTPUT key The AUX OUT socket is always on Press the right FIELD key to put the cursor in the numeric part of the top line and move the cursor a couple of digits to the right with the right DIGIT key You can experiment with the rotary control to adjust the frequency setting You can also experiment with enter
17. he local supply If it is necessary to change the operating voltage follow the procedure described in Appendix A of the Users Manual 271 Getting Started Manual Externally Applied Voltages AN Caution Front Panel Sockets To avoid risk of damage to the instrument Do not apply external voltages to the MAIN OUT or AUX OUT sockets Do not apply external voltages exceeding 10 V to the TRIG IN socket Caution Rear Panel Sockets To avoid risk of damage to the instrument Do not apply external voltages to the SYNC OUT or TRIG SWEEP OUT sockets Do not apply external voltages exceeding 10 V to the VCA IN socket Do not apply external voltages exceeding 7 5 V or 2 5 V to the CLOCK IN OUT socket Getting Started Controls and Connections Controls and Connections FLUKE EZB UU MIRI SN UI equo zi Ro 2 TRIG GATE FREQ PER PULSE RAMP O SQUARE O PULSE STAIR ARB O TRIANGLE SWEEP EDIT Cie 0s LOCAL 1 E 1 L1 EJ JAUUTUUUUUUUUUUI shx0001f gif Figure 1 Model 271 Front Panel 271 Getting Started Manual The Liquid Crystal Display The 4 line x 20 character LCD panel is used to display and edit all the parameter values The paradigm used for selecting fields and editing values is described below If necessary because of temperature variations etc you can
18. in which the length and level have been keyed in immediately before the final press of the ENTER key VALS ABS AUTO YES STEP 08 ACTIVE LENGTH 0005 LEVEL 153_ The remaining steps 9 to 15 inclusive are all inactive Press ESCAPE to complete this part of the set up You should see a brief display indicating that the instrument is making some calculations on the new waveform When the calculations are complete the display will return to the main menu on which you can complete the set up 22 by changing the amplitude to 1 0 V peak into 50 O and the frequency to 15 625 kHz or the period to 64 us To initiate the signal turn the output on and press the STAIR key Saving and Recalling Settings Having done all this work it would be wise to save the settings for future use You can do this simply by pressing the STORE key followed by a number in the range 1 to 9 and the ENTER key Store 0 is reserved for the factory default settings You can recall the set up at any time using the RECALL key Getting Started Using the Instrument Arbitrary Waveforms Arbitrary waveforms are best defined on a PC and downloaded to the instrument via the RS232 or GPIB interface Each is identified by a name with up to 16 characters Several commonly used waveforms are available from the internal read only memory ROM and can be recalled by pressing the EDIT then the ARB keys The display will look something like this RECALL ARB N
19. ing frequencies using the numeric keypad and with using the DIGIT key to adjust the frequency in decades to do this put the cursor under the rightmost units field Set a frequency for example 12 5 kHz You can do this by either of the methods above The easiest is probably to key FREQ PER 1 2 5 kHz ENTER 12 The display should look like this FREQ 12 50000kHz VhiZ 420 0 Vpp 502 DC 0 00mV 0 00mv SYM 50 0 50 0 You can also view and edit in terms of period Move the cursor into the first field and press one of the DIGIT keys The display should change to PER 80 00000us Vhiz 420 0 Vpp 500 DC 0 00mV 0 00mvV SYM 50 0 50 0 Set the amplitude to 10 dBm You can do this by keying AMPL 1 0 dBm The display will now look like this PER 80 00000us QUT 410 0dBm 500 DC2 0 00mV 0 00mv SYM 50 0 50 0 If you switch the amplitude display back to Vhiz you should see PER 80 00000us XhiZ 44 00 Vpp 500 DC24 0 00mV 0 00mv SYM 50 0 50 0 If you are using a 50 Q termination on the oscilloscope input then the signal amplitude will be half the displayed value 2 V p p Getting Started Using the Instrument Have a look at some other waveforms Using the function keys you can select any of the waveforms and observe them on the oscilloscope display Change the dc offset If the output is still set to 4 V p p then with the dc offset in the fractional mill
20. ivolts range you will not be able to see changes on the oscilloscope so the first thing to do is to force a range change Do this by pressing the DC OFFSET key and entering say 1 5 V You can then use the rotary control to adjust the waveform offset in steps which depend on the cursor position For smoother control press the right DIGIT key PER 80 00000us Vhiz 4 00 Vpp 500 DC 1 50 V 1 50 V SYM 50 0 50 0 Note that with the cursor placed as shown pressing the key will change the polarity of the offset voltage 13 271 Getting Started Manual Effect of the output attenuator The instrument has an output attenuator with fixed steps of 20 dB The attenuator follows the output stages so any dc offset added to the waveform is subject to the attenuator With the waveform amplitude set to 4 V p p the attenuator is switched out however if you adjust the output to say 0 4 V p p 20 dB of attenuation is switched in When this happens you will be warned that the dc offset has been changed Try it Set the amplitude to 4 V p p and the dc offset to 1 5 V Now change the amplitude by pressing AMPL 0 4 V The instrument will beep and you should see something like this for a few seconds WARNING 07 DC OFFSET CHANGE BY OUTPUT LEVEL kkkkkkkkkkkkkkkkkkkk 14 Then this PER 80 00000us Vhiz 4 00 Vpp 502 DC 1 50 V 151 mv SYM 50 0 50 0 The figure in brackets to
21. nal In the instrument the number of horizontal points which We can produce a table of all nine steps of the waveform make up the complete waveform is 1024 so the horizontal numbered 0 to 8 as follows steps must be scaled to the range 0 1023 Similarly the full scale signal amplitude is defined by values up to 511 so the vertical amplitudes must be scaled to to the range 0 511 20 Getting Started Using the Instrument amplitude start step amplitude step name start us scaled to 0 1024 length scaled to 0 511 0 0 3096 0 29 153 1 sync pulse 1 8 096 29 75 0 2 back porch 6 5 3096 104 90 153 3 50 grey 12 1 6596 194 165 332 4 white 22 4 100 358 165 511 5 50 grey 32 8 65 525 165 332 6 black 43 1 30 690 165 153 7 50 grey 53 4 65 854 165 332 8 front porch 63 7 30 1019 5 153 These values can now be entered in the staircase set up screens Press EDIT then the STAIR key You should see this screen VALS ABS AUTO YES STEP 00 ACTIVE LENGTH 0256 LEVEL 511 Change the length for the first step 00 to 29 and the level to 153 If you use the numeric and ENTER keys to make the change the step number automatically increments after the level has been entered 21 271 Getting Started Manual The second screen appears VALS ABS AUTO YES STEP 01 ACTIVE LENGTH 0256 LEVEL 000 Continue entering the pairs of length and level values in the table until the last step 08 This is the final screen
22. o 14 SINX X ENTER TO EXECUTE Or possibly like this RECALL ARB No 03 ARB 03 IS EMPTY ENTER TO EXECUTE The ROM is used for the factory preset waveforms 06 to 21 inclusive and the internal non volatile RAM is used for 23 271 Getting Started Manual arbitrary waveforms 01 to 05 These first five store locations are available for waveforms downloaded from a PC When you press the ENTER key the output switches to the selected waveform but the display does not change press ESCAPE to return to the main menu then press ARB and switch the output on to initiate the signal Note that there are no facilities for storing waveforms edited using the instrument itself However certain waveforms for example waveforms which emulate the effect of passing sharp edges through low pass filters can be generated without the aid of a computer There are some examples described in chapter 15 Application Examples of the Users Manual 24 Other Functions and Waveforms The instrument offers a number of additional capabilities and features which are beyond the scope of this Getting Started Manual These include e Amplitude modulation e Frequency hopping e Phase locking e Noise generation e Synchronizing two or more generators in master slave mode e Remote operation through the RS232 and GPIB interfaces These are all covered in detail in the Users Manual
23. performance within the specification limits Performance criterion B During test temporary degradation or loss of function or performance which is self recovering Performance criterion C During test temporary degradation or loss of function or performance which requires operator intervention or system reset occurs vi Table of Contents Title Page Introduction iret 1 Before XOU Start 2 icm a ae N a aa an aeie A ae Ea Nee 1 Mains Supply Voltage ritenere eE E Heu ege ia 1 Externally Applied Voltages essent 2 Gontrols and Connections ssa onde ire erp rine ttes taie ep escis 3 The Liquid Crystal DiSplay e re tere m Ee C 4 COMMONS i ee Need pact REG UG GE DER ee 4 Function Keys oe LE eere I eee cte e Pe Pete ge i e HEC D Cds 4 FIELD and DIGIT Keys and the Rotary 5 Numeric Units and SET 6 MODE I amp GyS unione repr reat rt ere cea aie ee in ee co ue CENA 7 UTILITIES Keys arte dre ette eden e li tes 7 QUTIPUT e ee 7 Front Panel Inputs and Outputs 8 ET 8 vii 271 Getting Started Manual AUX OUT zin piene e RPM 8 EXT TRIG Bit att ands ti dd daphne ed 8 Rear Panel Conriectots acean cere e ree dece ee EC de nodes 9 CLOCK INOU T 2 gh a ede
24. s not triggered mode so the settings for the trigger source the internal trigger generator and the burst count are not relevant here The only item on this menu which affects continuous modes as well as triggered and gated modes is the PHASE setting Move the cursor to the last digit of the phase numeric value field and use the rotary control to move the phase of the AUX OUT relative to that of the MAIN OUT SOURCE EXT TGEN 1 00ms 1 000kHz BURST COUNT 0001 PHASE 116 116 You may want to trigger the oscilloscope from the 15 271 Getting Started Manual instrument s AUX OUT socket in order to see the phase effects more clearly There are some limitations on using the phase control at frequencies above 30 kHz chapter 5 of the Users Manual explains these in detail 16 Generating Swept Signals The instrument has an independently controlled internal trigger generator which produces a square wave with a period from 20 us to 200 s in 20 us steps corresponding to a repetition frequency from 0 005 Hz to 50 kHz In most modes the signal is made available at the rear panel TRIG SWEEP OUT socket In sweep mode the sweep begins on the negative edge of the signal the transition from 4 to 0 V if you include markers in the sweep set up then each marker produces an additional narrow 1 V pulse on the TRIG SWEEP OUT signal For this tutorial we will generate a logarithmic sine wave sweep from 261 6 to 1108 7 Hz
25. st mode To synchronize an oscilloscope to the trigger generator rather than to the burst waveform itself connect the rear panel TRIG SWEEP OUT socket to the oscilloscope s trigger input Again by changing the trigger source to TRIG SRC MAN REMOTE you can initiate tone bursts by pressing the MAN SYNC key There are similar modes which use the internal trigger generator as the source of trigger signals and there are gated i e level sensitive modes which correspond to the edge sensitive triggered modes The Users Manual contains detailed information on these modes FSK Mode The FSK frequency shift keying mode can also be driven from the internal trigger generator Setting up is very straightforward the following settings give a continuous waveform which switches between 800 Hz and 1 2 kHz twice every second The edit menu for the FSK mode includes the basic settings for the trigger generator so there is no need to visit the trigger generator set up screen itself First free the internal trigger generator This is most easily done by returning to the factory default settings Press EDIT then FSK and enter the settings shown here FREQ A 800 0000 Hz FREQ B 1 200000kHz SOURCE TGEN FREE TGEN 250 ms 4 000 Hz Then press FSK again to start the generator with the new settings and turn the output on Getting Started Using the Instrument Special Waveforms Staircases The instrument can generate a staircase wav
26. t ra p MIS 9 Med PF 9 eL 9 TRIG SWEEP OUT watts ehm tede Ded te E ese tede ge dece etd ente 10 RS232 and GPIB Interface Connectors 10 Using the Iristr rmnent iere i ct erbe RU pa ee De pee ee 11 irte e PRECES EORR 11 Generating Continuous Signals sesseeeeeeneeeneenenneen nene 12 Generating Swept Signals sessessesseseseeeeeeee enne nnne 16 Generating a Triggered Burst nennen nennen nene 18 Special Waveforms io ete eee a ete er uu 19 Saving and Recalling Settings seen 23 Arbitrary WavefOrms 1 3 oet E eec EE D dece e tee 23 Other Functions and Waveforms sssssssssseeeeeeeeeen nennen nennen nnne 24 viii Introduction This Getting Started Manual for the model 271 Programmable 10 MHz DDS Function Generator is designed to provide an initial understanding of the way the instrument is operated The manual is set out in the form of a tutorial guiding you through a series of basic front panel operations in order to familiarize you with the controls and the modes of operation The Users Manual contains detailed specifications and descriptions of all the functions and operations accessible both from the front panel and by means of the remote interfaces Getting Started Before You Start Mains Supply Voltage Check that the instrument operating voltage marked on the rear panel is correct for t
27. y the user to ensure safe operation and to retain the instrument in a safe condition This instrument has been designed for indoor use in a Pollution Degree 2 environment in the temperature range 5 C to 40 C 20 80 RH non condensing It may occasionally be subjected to temperatures between 5 C and 10 C with out degradation of its safety Do not operate the instrument while condensation is present Use of this instrument in a manner not specified by these instructions may impair the safety protection provided Do not op erate the instrument outside its rated supply voltages or environmental range AA Warning To avoid the possibility of electric shock e This instrument must be earthed e interruption of the mains earth conductor inside or outside the instrument will make the instrument dangerous Intentional interruption is prohibited The protective action must not be negated by the use of an extension cord without a protective conductor e When the instrument is connected to its supply terminals may be live and opening the covers or re moval of parts except those to which access can be gained by hand is likely to expose live parts 271 Getting Started Manual e The apparatus shall be disconnected from all voltage sources before it is opened for any adjustment replacement maintenance or repair e Any adjustment maintenance and repair of the opened instrument under voltage shall be avoided as far as possibl
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