DCM555 - Data Communications Lab 6 Transferring Waveforms
Contents
1. ArrayFormat Block area eparator PY MultiFieldForma E Design E IconAppearance IconPicture Centered Showlcon itle True F i g u re 6 In the Data Format section ensure that the Array Format is Block and the Array Separator is set to a comma between double quotes This uses a comma as the delimiter between each character of the string which is formed from the array The Data Format part of the To String Properties box should appear as shown on the right of Figure 6 This will insert an ASCII comma character between sample characters In the To String object double click on the Transaction Line and form a transaction as shown in Figure 7 Make sure the String Formatis selected kO Transaction ARITE TEST la STRINGFORMAT oe ALL CHARS EOL GN OK MOF Cancel Figure 7 Select OK and connect the output of the Unbuild Waveform object to the Real64 Ary input of the To String object This part of the program should appear similar to Figure 8 The Unbuild Waveform object separates the waveform Time Span from the actual waveform samples ee he CH Reald Ary i AlphaMumerit To String Time Span I WRITE TEXT a STR EOL Double Click ta Add Transaction Figure 8 17 Insert a Logging Alohanumeric object into the work space from Display gt Logging Alohanumeric This is the type of display used for strings Connect the Result output of the2. Dcortfset Func 4 ee Phase igs Time Span 8 Num Points T 456 4 Figure 3 12 Push the Play button Precisely what do you see Use the horizontal and vertical sliders to move around the display Right click on the Waveform Display object and experiment with the Auto Scale and Zoom features Also experiment with the settings under Properties gt Scales 13 Move the mouse cursor over the line connecting function generator and display It will change into a magnifying glass as shown in Figure 4 Ea Trat Figure 4 Click on the line This shows the contents of the waveform Describe precisely what information about the waveform is displayed 4of 10 Seneca College School of Information and Communications Technology C Rodgers 14 How does the number of elements in the array correspond to the number of points set in the function generator object Record the value in any element of the array except the first and the element index You will use this later Array value Array index 15 We will now prepare the waveform data for transfer to the 33220A Arbitrary Waveform generator The waveform data is actually a composite data type consisting of the array and a Time Span We need to Unbuild the waveform first Insert an Unbuild Waveform object into the work space from Data gt Unbuild Data gt Waveform Double click on the object Insert two alohnumeric displays from Display gt Alphanumeri
3. look like Figure 9 Examine the command explanations and make sense of them for yourself ReSeTs the 33220A Sets the output for an INFinite LOAD i e the scope 1MQ Waveform to be transferred to 33220A VOLATILE memory from W input Sets the USER waveform to VOLATILE Sets waveform FREQuency from F input Sets VOLTs UNIT to Vp p Sets waveform amplitude from A input Assigns current waveform FUNC to USER Turns OUTPut to ON 19 Insert sliders for F and A as in Step 8 Set each slider to Auto Execute by setting the AutoExecute Behaviour in the slider Properties window to True This will cause your VEE program to execute whenever the slider settings are changed eliminating the need to push the Play button See Figure 10 Seneca College School of Information and Communications Technology C Rodgers Connect the Result output of the To String object to the W input When complete your program should appear similar to Figure 11 Set the slider minimum and maximum values to those shown m Functinn CGarnaratar r CHON Generale Function Sine Frequency 1 Amplitude 1 Deofset oo Fhase Deg o Time Span 7 S gt Num Points TEG o2 04 06 08 1 Time F result Realh4 Ary i Time Span li WRITE TEXT RST EOL WRITE TEXT QUTP LOAD INF EOL WRITE TEXT DATA VOLATILE WW EOL WRITE TEXT FUN C USER YOLATILE EGL WRITE TEXT FREQ F EOL WRITE TEST YOLTU
4. Address e Agilent DSO X 2002A Mixed Signal Oscilloscope Utility gt I O gt LAN Settings then IP Address DSO X 2002A IP Address 2 Turn on one of the lab station PCs and log on 3 From Windows launch VEE Pro from the desktop icon Agilent folder 4 It will be necessary to first establish the LAN connection interfaces in VEE Pro for all devices to be used Follow the procedure used in the previous Intro lab to initialize the VEE LAN TCP IP interface NOTE It is often a good idea to keep a VEE Pro template file set up for your lab station If the Save I O Configurations with Program box is checked when saving the file in the last lab all interface configuration data will be retained and it will be unnecessary to repeat these steps the next time when you simply open the template file in VEE Pro then save it with a new name keeping your template file pristine for future use 1 of 10 Seneca College School of Information and Communications Technology C Rodgers 5 We ll now use VEE to access a function built into the 33220A which produces an AM waveform Create a Direct I O box for the 33220A into the VEE workspace Enter the following Standard Commands for Programmable Instruments SCPI program into the 33220A transaction box FUNC SHAP SIN VOLT UNIT VPP VOLT 1 0 FREQ 100E3 AM INT FUNC SIN AM INT FREQ 1E3 AM DEPT 50 AM STAT ON OUTP ON When completed the transaction box should appear similar to
5. Auto Execute pull down menu Change the value from False to True This causes the VEE program to automatically run whenever the slider position is changed From the Properties window you can also change the slider titles from Real64 to more appropriate names like Carrier Freq etc 2 of 10 Seneca College School of Information and Communications Technology C Rodgers When completed the program should appear similar to Figure 2 Set the minimum and maximum values for each slide bar as shown en ee ee ee ee oe Aar lacetti aont fama ssa ee fT oe De Cee CST oe F Biani Put Hef beat 2h i F O a E UTI of fs S UW pad peat saint r ii SPD ptr mT aha F Baes E A TAA r WRITE TEXT FUNG SHAFP SIN EGL ARITE TEST OLTUMNIT YPP EOL WRITE TEXT VOLT 1 0 EOL WRITE TEXT FREQ fe EOL WRITE TEXT AMINT FUNG SIN EOL WRITE TEST AMINT FREG fi EOL WRITE TEXT AW DEPT m EOL WRITE TEXT AM STAT ON EGL WRITE TEXT OUTP ON EOL Double click to Add Transaction Figure 2 8 Turn the DSO X 2002A to Run Vary each of the slide bars in turn and look at the DSO X 2002A display Describe what happens 9 Set the AM waveform for a 100kHz carrier a 1kHz intelligence and a modulation index of 100 Set the time base to 500us div Capture and save the DSO X 2002A time domain display for your report 10 Select the frequency domain function of the DSO X 2002A Math gt FFT Turn Off the time domain displa
6. Figure 1 Examine the command explanations and make sense of them for yourself Sets carrier signal type FUNC to SINe Sets VOLTs UNIT to Vp p Sets carrier amplitude WRITE TEXT FUNC SHAP SIN EQL 4 WRITE TEXT VOLT UNIT YPP EOL WRITE TEXT VOLT 1 0 EOL WRITE TEXT FREQ 100E3 EOL WRITE TEST AMINT FURMIC SIN EOL WRITE TEAT AMINT FREQ 1E3 EOL Sets INTernal modulating WRITE TEST AM DEFPT 50 EOL FREQuency WRITE TEXT AM STAT ON EOL Sets AM DEPTh J Sets carrier FREQuency sets INTernal modulating signal type to SINe WRITE TEXT OUTP ON EOL Double Click to Add Transaction modulation index Sets AM STATus to ON Figure 1 Turns OUTPut to ON 6 Connect the 33220A output to the DSO X 2002A probe Set the time base to 500us div Run the program An AM waveform should appear on the oscilloscope display Stop the DSO X 2002A and view the AM waveform Use the oscilloscope cursor functions to measure the carrier frequency and modulating frequency from the envelope Also determine the modulation index Record your values below Recall m 7 Modify your program to make the carrier frequency the intelligence frequency and the modulation index all variable from a slide bar from Data gt Continuous gt Real64 Don t forget to put a space before the As each slide bar is inserted examine the Properties window on the left of the screen Under Behavior select the
7. RBIT YPF EOL WRITE TEXT VOLT A EGL WRITE TEXT FUNC USER EOL WRITE TEXT QUTP ON EOL Double Clickto Add Transaction Figure 11 20 Ensure that the output of the 33220A is still connected to the probe to the DSO X 2002A Oscilloscope Push the Auto Scale button on the DSO X 2002A Push the Play button for your program Watch the DSO X 2002A scope display After a delay the 33220A waveform should change to that generated by your program Experiment with varying the function generator waveform and the frequency and amplitude sliders What takes place 21 Change the number of points in the function generator object to 1000 Push Play and again examine the waveform using the magnifying glass What changed Change the number of points to 5 and push Play Describe the waveform displayed on the DSO X 2002A 8 of 10 Seneca College School of Information and Communications Technology C Rodgers Also try other larger values including up to 64k that is 65 536 pushing play then watching the DSO X 2002A display each time What do you notice about the time taken to transfer the waveform over the LAN Return the number of points in the function generator object to 256 22 Adjust the frequency slider to 1000 and the amplitude to 2 On the DSO X 2002A set the vertical amplifier to 500mV div and the timebase to 2ms div Capture and save the DSO X 2002A time domain display for your report Activate the FFT of t
8. Seneca College School of Information and Communications Technology C Rodgers DCM555 Data Communications Lab 6 Transferring Waveforms over the LAN Name St Section Note Show all of your calculations express your answer to the appropriate number of significant digits at least three and use the correct units in your answer Place your answer in the space provided Lab Objectives e to review LAN amp GPIB configuration procedures for remote control of Agilent instruments e to access and vary settings for the built in waveforms of the Agilent 33220A Function Arbitrary Waveform Generator e to use Agilent Visual Engineering Environment VEE Pro to create arbitrary waveforms and send them to the Agilent 33220A Function Arbitrary Waveform Generator over the LAN for production Components Required e none Equipment Required With DSO X 2000 e Agilent 33220A Arbitrary Waveform Generator _ series Oscilloscope e Agilent Keysight DSO X 2002A Mixed Signal Oscilloscope e Agilent Visual Engineering Environment VEE Pro Lab Exercise Built in Arbitrary Waveforms 1 Turn on the Agilent 33220A Function Arbitrary Waveform Generator and the Agilent DSO X 2002A Mixed Signal Oscilloscope Determine the LAN address for each instrument device to be used and record them below Do not change any of the LAN IP addresses and configuration e Agilent 33220A Function Arbitrary Waveform Generator Utility gt O gt LAN Current Config 33220A IP
9. To String Object to the Logging Alphanumeric input 6 of 10 Seneca College School of Information and Communications Technology C Rodgers RST OUTP LOAD INF DATA VOLATILE W FUNC USER VOLATILE FREQ F VOLT UNIT VPP VOLT A FUNC USER OUTP ON TO Paria ea ee See ee Ne Re a nee a ge a ee ieee Pee eee eee RE z a p F DRE iaaa an y e py be rya T ere n a an i a ag T e A aA Srn aan da an T EN a F ag PS PS Aas rl marn 1 ami ei A a l T ie g Taare ells i a PIP dh bee oa zeh WRITE TEXT REST EOL WRITE TEXT QUTP LOAD INF EOL WRITE TEST DATA VOLATILE YW EOL WRITE TEXT FUNC USER VOLATILE EOL WRITE TEXT FREGQ FEOL B WRITE TEXT VOLT UNIT FP EQL lt q WRITE TERT VOLT A EOL WRITE TEXT FUNC USER EOL WRITE TEXT OUTP ON EOL Double Click to Add Transaction Es A Ba Anm Figure 9 E Behavior AutoE secube Break pointe nabled Wait For Input Desinn True Figure 10 7 of 10 True Push the Play button Describe how the Logging Alphanumeric Display data differs from the Alphanumeric Display of the array 18 From the Instrument Manager insert a 33220A transaction box into the work space Enter the following sequence of transactions This will insert three inputs on the transaction box one each for frequency F amplitude A and the waveform string W When complete the 33220A I O transaction box should
10. c and connect them to the Real64 Ary and Time Span outputs of the Unbuild object The program should appear similar to Figure 5 Function Generator Function Sine 0 8 0 6 Frequency 1 mag 0 4 0 2 Amplitude 0 2 Dcofset 0 cd 0 6 Phase Deg 0 Trace U8 Time Span 1 HI Mur Points J56 Jiem es LINE J rset i t Realit Ary Wit Data jan p Time Span Figure 5 Push the Play button What do the two alphanumeric displays show Use the slide bar if present 16 We will now convert the data to a string that is to say 8 bit digital samples of will be treated as ASCII character This is a data format which can be received and understood by the 33220A Insert a To String object into the work space from I O gt To gt String Right click on the To String object and select Properties A Properties side panel will appear on the left side of the screen as shown on the left of Figure 6 5 of 10 Seneca College School of Information and Communications Technology C Rodgers To String To String M 5 M ae 24 E Appearance BackColor C Object Font Object Text ForeColor BB Object Text ShowT erminals True ShowTitleB ar True El Data Format Title To String Title BackColor Object Title ArayF ormat Block Title Font Object Title Text TET TjjSareee Ti Array Separator f Behavior BreakpointEnabled False ha lt eld ormat Surber E DataFormat
11. he DSO X 2002A Math gt FFT and turn off the time domain display Under Settings set the Center frequency to 5kHz and the Span to 10KHz Use the Cursor function to measure the spectral peak frequency Capture and save the DSO X 2002A frequency domain display for your report 23 Turn off the FFT display and turn the time domain display back on with the timebase set to 500us div In your VEE program change the frequency in the function generator object to a non integral value such as 1 2 Push the Play button Describe what you observe on the DSO X 2002A Capture and save the DSO X 2002A time domain display for your report 24 Adjust the time base back to 2ms div Reactivate the FFT and turn off the time domain display Use the Cursor function to measure the spectral peak frequencies Describe what you observe on the DSO X 2002A Capture and save the DSO X 2002A frequency domain display for your report 25 Using the Function menu of the VEE Function Generator experiment with other waveforms such as Square and so forth Change the amplitude and frequency settings and observe the corresponding changes in the time and frequency domain of the DSO X 2002A 9 of 10 Seneca College School of Information and Communications Technology C Rodgers Further study 26 In Step 6 did the measured values for fc fi and m equal those specified by the program If not offer a possible reason why 2 Describe the advantage of the slide ba
12. r Auto Execute feature 28 How does your estimate FFT resolution in Step 11 compare with the IFR spectrum analyzer used previously in A4056 Why is spectrum analysis FFT resolution important 29 From the array index you recorded in Step 14 calculate what the array value should be Hint You divided one sine wave cycle into 255 intervals How does this compare with the value recorded in Step 14 Calculated Array value 30 Based on Step 15 give the advantage and disadvantage of increasing the number of waveform points 31 The waveform generated in your program was transmitted in a string format Describe a disadvantage of transmitting the waveform as a string 32 What was the difference between the 33220A waveform in Steps 22 and 23 Based on the FFT Spectra for Step 22 and 23 describe the precautions which must in general be taken when transmitting an arbitrary waveform 10 of 10
13. y Under Settings adjust the Center frequency to that of the carrier and the Span to 10kHz Use the cursor functions to measure the three peak frequencies and powers in dBV Record them below P fp P fe P Capture and save the DSO X 2002A frequency domain display for your report Adjust each of the sliders and monitor what happens in the spectrum By varying the intelligence frequency lower and lower try to determine the maximum resolution of the DSO X 2002A FFT that is the minimum discernable frequency separation between spectral peaks FFT resolution There are other built in modulation types and arbitrary waveforms in the 33220A all of which can be accessed from a User I O interface as above Search for the 33220A User Manual at www agilent com 3 of 10 Seneca College School of Information and Communications Technology C Rodgers User Defined Arbitrary Waveforms 11 We ll now use VEE to generate waveforms Start a new VEE Pro program File gt New Select Device gt Virtual Source gt Function Generator and place the object on the work space Then select Display gt Waveform and place the object on the work space Join the output of the function generator Func to the input of the display Trace 1 Change the Function to Sine and the Frequency and Time Span both to 1 The program should appear similar to Figure 3 Mag oe 0 6 Function 0 4 Frequency 0 2 Amplitude 0 2
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