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Introduction to NI ELVIS

1. Op Amp Ly Zi Gain Basic R R Rel R Highpass R R Xc Re R Xc7 Lowpass Re Xe R Re Xc R Bandpass Ret Xer Ri Xc Re Xo Ri Xc For any frequency you can use the Impedance Analyzer to measure the impedances Zr and Z A LabVIEW program can calculate the ratio of two complex numbers The magnitude of the ratio IZ Z is the gain 3 Note You can also use the Impedance Analyzer to find the frequencies where R4 equals Xc and Ry equals X to verify that the lower and upper frequency cutoff points from the Bode plot are equal to these frequencies National Instruments Corporation 4 15 Introduction to NI ELVIS Digital 1 0 Digital electronics is the heart and soul of modern computers The ability to set and read digital lines is essential to digital circuit diagnostics oii amp a Hu Big teH ETT ee Figure 5 1 Typical NI ELVIS Protoboard Circuit National Instruments Corporation 5 1 Introduction to NI ELVIS Lab5 Digital 1 0 Goal This lab focuses on the NI ELVIS digital tools such as a digital clock digital counter and a logic state analyzer to study circuits Soft Front Panels Used in This Lab This lab requires the following SFPs Digital Writer Digital Reader Oscilloscope Components Used in This Lab This lab requires the following components Introduction to NI ELVIS 10 kQ resistor Ra brown black
2. NATIONAL INSTRUMENTS MANUAL SUPPLY Voltage aliras Sa tz 6 09 v RESET 3 From either the workstation front panel controls or the SFP virtual controls test the motor End of Exercise 10 1 National Instruments Corporation 10 3 Introduction to NI ELVIS Lab 10 Mechanical Motion Exercise 10 2 The Tachometer Using an IR LED and phototransistor or an integrated LED phototransistor module you can build a simple motion sensor Complete the following steps to build a simple motion sensor 1 On the protoboard insert the components shown in the circuit diagram in the following figure Emitter Detector 5 V 1 Kas 10 KQ To ACH4 GND 7 In the case of an LED phototransistor module an internal LED is used for the optical source and is powered from the 5 V power supply A 1 kQ resistor is used in series with the LED to limit the current A 10 KQ resistor is connected from the phototransistor emitter to ground and the same power supply is connected to the phototransistor collector The voltage developed across the 10 kQ resistor is the phototransistor or tachometer signal 2 Connect leads from the 10 KQ resistor to ACH4 and ACH4 pin sockets Introduction to NI ELVIS 10 4 ni com Lab 10 Mechanical Motion 3 Select Oscilloscope from NI ELVIS Instrument Launcher and select the settings shown in the following figure gt NI ELVIS Oscilloscope E a 5
3. 3 Close the NI ELVIS software suite and launch LabVIEW 4 From the Hands On NI ELVIS VI Library folder select Rc Transient vi This program uses the LabVIEW API to turn the power supply on for five seconds then off for five seconds while the voltage across the capacitor is displayed on a LabVIEW chart This type of square wave excitation dramatically shows the charging and discharging characteristics of a simple RC circuit as shown in the following illustration The circuit time constant T is defined as the product of R3 and C Introduction to NI ELVIS 1 10 ni com Lab1 MI ELVIS Workspace Environment RC Charging and Discharging 6 0 5 0 4 0 3 0 R 2 0 1 0 o l y a 9 gt p m 9 a 0 S 1 j 1 I 0 10 20 30 40 50 60 70 80 90 100 Time 0 1 sec Kirchoff s laws show that the charging voltage V across the capacitor is given by and the discharge voltage Vp is given by You can extract the time constant from the measured chart Observe the LabVIEW diagram window to see how this program works RC Charging and Discharging oma od oKees eee Doo i ooo ET 0 IN 0HN lt lt Double click DAQ lt lt Double click DAQ Jassistant to change Jassistant to change b
4. 4 Select the function DMM A and measure the current I calculated I measured 5 How well does the measured value agrees with the calculated value End of Exercise 1 3 National Instruments Corporation 1 7 Introduction to NI ELVIS Lab1 NI ELVIS Workspace Environment Exercise 1 4 Observing the Voltage Development of an RC Transient Circuit Complete the following steps to observe the voltage development of an RC transient circuit 1 Build the RC transient circuit as shown in the following figure It uses the voltage divider circuit where R is now replaced with R3 1 MQ resistor and R is replaced with the 1 uF capacitor C 2 Move the front panel leads back to the DMM VOLTAGE inputs and select DMM V To 5V To DMM Voltage HI 1 uF To Ground lt q af To DMM Voltage LO 3 Note The NI ELVIS version 1 workstation has limited input impedance 1 MQ for the DMM channel To read the correct voltage values you must buffer the input voltage for this measurement Refer to the Limited Input Impedance Solution section for a simple solution using a unity gain circuit with a FET Op Amp This limitation will be remedied in a future version Using the analog input channels of the DAQ device as described in Exercise 1 5 prevents this problem When the circuit is powered on the voltage across the capacitor rises exponentially Power on the circuit and watch the voltage change on the DMM
5. EEE V i 8 Complete the following steps to build and perform measurements on a 555 digital clock circuit 1 Using the DMM Q and DMM C measure the component values and fill in the following Ry Q 10 kQ nominal Rpg Q 100 kQ nominal C UF 1 uF nominal 2 Build the clock circuit on the protoboard as shown in the following figure Voc gt 5 V 4 8 R A 555 L 3 Output i Discharge ae Rg 3 8 Threshold 2 _ Trigger Cas 1 C 1uF Power 5 V goes to pins 8 and 4 and the ground goes to pin 1 The timing chain of R4 Rpg and C straddles the power supply It has a connection between the resistors going to pin 7 and a connection between Rpg and C going to pins 2 and 6 3 Wire the 555 output pin 3 to the parallel input port pin socket DI 0 i Note The digital input pins lt DIO 0 7 gt are located in the upper right hand corner of the NI ELVIS protoboard National Instruments Corporation 5 5 Introduction to NI ELVIS Lab5 Digital 1 0 Introduction to NI ELVIS 4 From the NI ELVIS Instrument Launcher select Digital Reader check your circuit and enable power to the protoboard on the NI ELVIS workstation NI ELVIS Digital Bus Reader NATIONAL INSTRUMENTS en sme The Digital Bus Reader allows the current state of the parallel input port to be read on demand single shot or continuously If the clock
6. Set the Mode to Continuous and Pattern to Manual as shown in the following figure gt NI ELVIS Digital Bus Writer NATIONAL INSTRUMENTS Pattern Manual Manual Pattern ame Wy Y 6 5 4 Action 2 Shift Left Right 7 9 Introduction to NI ELVIS Lab7 LEDs to the Rescue 9 To activate the port click the Write button When all switches bits 0 2 and 4 6 are HI all the LEDs should be lit When all these switches are LO all the LEDs should be off You can now use these switches to find out what 8 bit codes are necessary to control the various cycles of a stoplight intersection Here are some clues for the intersection The basic operation of a stoplight is based on a 60 second time interval with 30 seconds for red followed by 25 seconds for green followed by 5 seconds for yellow For a two way intersection the yellow light say in the North South direction is on while the red light in the East West direction is also on This modifies the 30 second red timing interval to two timing intervals a 25 second cycle followed by a 5 second cycle There are four timing periods T1 T2 T3 and T4 for a two way intersection 10 Study the following chart to see how a two way stoplight intersection works LEDs North South East West Timing R Y G R Y G Timing Interval 8 Bit Numeric Period seconds 0 1 2 4 5 6 Code Value Tl
7. NATIONAL CHANNEL B INSTRUMENTS AS E A Display Display Source Source BNC Board CHA w BNC Board CHB w VERTICAL VERTICAL Position Position D a Scale Scale A J 2y v idiv J 1 v idiv Coupling Coupling TIMEBASE TRIGGER Source D Immediate J CURSORS Timeout Run e Single Log i D Acquired ay Note ACH4 inputs are the same source as BNC Board CH B on the protoboard 4 Power on the protoboard and run the Oscilloscope SFP 5 Pass a piece of paper through the IR motion sensor You should see the oscilloscope trace change HI LO HI With a thin piece of paper you might catch the pulse generated as you drag it through the sensor 6 Pass acomb with many teeth through the sensor Dragging it through the sensor generates a train of pulses You can run it back and forth through the sensor to generate a continuous stream of pulses as shown in the previous figure End of Exercise 10 2 National Instruments Corporation 10 5 Introduction to NI ELVIS Lab 10 Mechanical Motion Exercise 10 3 Building a Rotary Motion System The rotary motion demonstration system consists of the DC motor controlled by the variable power supply and the IR motion sensor configured as a tachometer To complete the tachometer you must attach a disk of about 2 in diameter disk to the shaft of the motor by completing the Introduction to NI ELVIS following steps 1 Cuta 2 in diameter disk from a pie
8. ELVIS Lab 10 Mechanical Motion Exercise 10 5 A LabVIEW Measurement of RPM LabVIEW has several VIs in the Functions All Functions Waveform Waveform Measurements palette that are convenient for measuring timing periods of a continuous waveform The Pulse Measurements vi can measure the period pulse duration or duty cycle from a waveform array RPM x1000 Pulse Measurements vi 3 Note If you are using LabVIEW 7 0 or later you can use the Express template for Timing and Transitions Measurements You can convert the period measurement to RPMs by inverting the period to get frequency then multiplying by 60 to get RPM For scaling divide by 1 000 to get KRPM Using Lab VIEW complete the following steps to measure timing periods on a continuous waveform 1 Launch LabVIEW and open RPM vi from the Hands On NI ELVIS Library folder 2 Open the diagram window and study the program samples per channel DAQmx Physical OAQmx Create IDAQm x Start Channel Virtual Channel vi pevanje Al Voltage Sample Clock INI ELVIS Initialize vi INI ELVIS YPS Initialize vi JPS INI ELVIS VPS Update vi JPS 5 00 Calculates Running Average Introduction to NI ELVIS 10 8 ni com Lab 10 Mechanical Motion Data acquisition VIs are used to sa
9. OUT 2 7 6 gt y 741 To CHB OSC Ground 4 Configure the SFP function generator for TTL output levels e Amplitude 2 2 V e Offset 2 5 V e Waveform Square e Frequency 1 kHz 5 Observe the transmitted and received signals on the oscilloscope e Channel A goes to pin 3 of the 7408 chip the transmitter signal e Channel B goes to pin 6 of the Op Amp the receiver signal 6 Trigger on Channel A You should see the transmitted message S on Channel A and the received signal on Channel B End of Exercise 9 5 Introduction to NI ELVIS 9 10 ni com Lab9 RF Wireless Communication For Further Exploration Hearing is Believing With a little more gain on the receiver side and a conversion of the signal into a current you can drive a small loudspeaker to hear beep beep beep pause beep beep beep faintly but clearly Enjoy the challenge National Instruments Corporation 9 11 Introduction to NI ELVIS Mechanical Motion The ability to translate electrical signals into motion in the real world coupled with the ability to measure position allows you to exploit the power of the computer to generate computer automation the source of much of the modern world conveniences Goal In this lab the NI ELVIS variable power supply capacity is used to run and control the speed of a small DC motor Using a modified free space IR link a tachometer is built to measure the sp
10. T T T o T T 5 T Se T T o T 5 T E T O wo Ww 1O wo O ie LO o q T T l N N oO B g Temperature C Figure 2 1 Resistance Temperature Curve of a Thermistor End of Exercise 2 1 National Instruments Corporation 2 3 Introduction to NI ELVIS Lab2 Digital Thermometer Exercise 2 2 Operating the Variable Power Supply Complete the following steps to take a measurement using the variable power supply 1 From the NI ELVIS Instrument Launcher select Variable Power Supplies There are two controllable power supplies with NI ELVIS 0 to 12 V and 0 to 12 V each with a 500 mA current limit 2 Onthe NI ELVIS workstation slide the VPS switch to Manual 3 Note In manual mode the controls on the VPS SFP are grayed out and you cannot use the controls A green LED indicates that the VPS is in manual control In manual mode only the front panel controls can change the output voltage 3 Connect the leads from VPS and Ground sockets of the NI ELVIS prototyping board to the workstation DMM voltage inputs 4 Select DMM V 5 Rotate the manual VPS knob on the workstation and observe the voltage change on the DMM V i Note The zero voltage position for VPS control is counter clockwise CCW and for VPS control is clockwise CW NI ELVIS Variable Power Supplies NATIONAL INSTRUMENTS MANUAL MANUAL SUPPLY SUPPLY Voltage Voltage silty sili ah the ube TRE A Y
11. and a high gain Op Amp is the receiver The classic message is formulated using the NI ELVIS arbitrary waveform generator Soft Front Panels Used in This Lab This lab requires the following SFPs Oscilloscope OSC Arbitrary Waveform Generator ARB Components Used in This Lab This lab requires the following components Introduction to NI ELVIS 1 kQ resistor brown black red Two 100 kQ resistors brown black yellow 741 Op Amp or FET Op Amp 753 7408 digital IC Paper clip 9 2 ni com Lab9 RF Wireless Communication Exercise 9 1 The Transmitter Complete the following steps to build a simple antenna from a paper clip 1 Straighten a paper clip and cut it into a 2 5 in long piece 2 Push one end of the paper clip into the output pin socket of the function generator When FGEN is running the output voltage leaks out of the pin socket to the paper clip antenna and radiates a small RF signal A similar antenna about a centimeter away can pick up this signal and amplify it to a higher signal level You will use the transmitter in Exercise 9 2 1 Straight Paperclip 2 Stepped Paperclip Figure 9 1 Paperclip Antenna 3 Initially use a sine wave to test the transmitter by setting the SFP function generator to sine waveform 2 5 V amplitude and 10000 Hz frequency End of Exercise 9 1 National Instruments Corporation 9 3 Introduction to NI ELVIS Lab9 RF Wireless Communication E
12. can see the curves developed quickly resulting in a family of IV curves with different individual base currents Observe that for a given collector voltage the collector current increases with an increase in base current A phototransistor has no Base lead Instead light falling on the transistor generates a base current proportional to the light intensity For example with no light the transistor follows the bottom yellow curve A low light level follows the middle red curve and a higher light intensity generates the upper green curve For collector voltages greater than 0 2 V such as 1 0 V the collector current follows the light intensity falling on the base region in an almost linear fashion To build an optical detector all that you need is a power supply a current limiting resistor and a phototransistor as shown in the following figure 8 4 ni com Lab 8 Free Space Optical Communication Output 5V K Phototransistor a4 3 470 Q T GND 5 Close any SFPs End of Exercise 8 1 National Instruments Corporation 8 5 Introduction to NI ELVIS Lab 8 Free Space Optical Communication Exercise 8 2 Introduction to NI ELVIS Infrared Red Optical Source The optical transmitter is made up of two components an IR LED forward biased and a current limiting resistor Complete the following steps develop a simple optical data link 1 Connect the IR LED to the DMM current inputs Make
13. circuit is running correctly and continuously as shown in the previous figure you should see the least significant bit flashing If not use the DMM V to check the voltage on the 555 pins With the clock circuit running you can now make some useful circuit measurements The 555 Timer oscillator circuit has a Period T of T 0 695 R 2Rp C seconds The 555 Timer oscillator circuit frequency is related to the period by F tHe The 555 Timer oscillator circuit has a Duty Cycle On time Period of pea Rat Re Ry 2R Close all SFPs and click the Oscilloscope button Connect the front panel BNC Scope CH A input leads to pin 3 of the 555 Timer chip and any ground You should now observe the digital waveform on channel A of the oscilloscope Select Trigger Source CH A This option takes the signal from channel A sets the Trigger Type to Analog SW and allows you to set the Trigger slope and Level Set the Level to 1 V Utilizing the MEAS option for channel A observe the frequency in the scope window Turn CURSORS CH A button ON by clicking and dragging the Cursors 10 Measure the period and duty cycle 5 6 ni com 11 12 13 Lab5 Digital 1 0 Fill in the following information T seconds y seconds DC volts F Hz Compare the measurements with the previous theoretical predictions Close any SFPs End of Exercise 5 2 National Instruments Corporation 5
14. diode across the DMM current leads Make sure the cathode is connected to the black banana input 2 Launch the NI ELVIS Instrument Launcher and select Two Wire Current Voltage Analyzer A new SFP opens that allows you to display the I V curve for the device under test This SFP applies a test voltage to the diode from a starting voltage level to an ending level in incremental voltage steps all of which you can select 3 For a silicon diode set the following parameters e Start 2 V e Stop 2 0 V e Increment 0 1 V 4 Set the maximum current in either direction to ensure the diode does not operate in a current region where damage can occur 5 Click Run to see the I V curve i NI ELVIS Two Wire Current Voltage Analyzer Settings NATIONAL INSTRUMENTS Voltage Sweep v Start Stop 2 00 2 00 Increment o10 g Current Limits mA Negative Positive 10 00 10 00 Display Autoscale Mapping Voltage Current OFF Linear Linear Cursor Position National Instruments Corporation 7 5 Introduction to NI ELVIS Lab7 LEDs to the Rescue Introduction to NI ELVIS In the reverse bias direction the current should be very small uA and negative In the forward bias direction you should see that above a threshold voltage the current rises exponentially to the maximum current limit 6 Change the Display buttons Linear Log to see the curve plotted on a different
15. display It takes about five seconds to reach the steady state value of V When you power off the circuit the voltage across the capacitor falls exponentially to 0 V Introduction to NI ELVIS 1 8 ni com Lab1 NI ELVIS Workspace Environment 3 Power up and then power off the circuit to observe the rise and fall of voltage In Exercise 1 5 you will view this transient effect on a plot of capacitor voltage versus time Limited Input Impedance Solution Using an FET Op Amp such as the LM356 build a unity gain circuit and connect it as shown in the following figure By connecting the output pin 6 to the input pin 2 the gain of this circuit is set to 1 However the input impedance pin 3 is now hundreds of megaohms and the output voltage pin 6 follows the capacitor voltage allowing the DMM voltage input to read the correct values To 5V ue To DMM Voltage HI 1 uF ae Capacitor To Ground lt gt To DMM Voltage LO End of Exercise 1 4 National Instruments Corporation 1 9 Introduction to NI ELVIS Lab1 NI ELVIS Workspace Environment Exercise 1 5 Visualizing the RC Transient Circuit Voltage Complete the following steps to visualize the RC transient circuit voltage 1 Remove the 5V power lead and replace it with a wire connected to the Variable Power Supply socket pin VPS as shown in the following figure 2 Connect the output voltage V to ACHO and ACHO
16. displays the word Good as shown in the following figure gt NI ELVIS Digital Multimeter NATIONAL INSTRUMENTS v v ax ar a 4 oon Function Nun VDC Run Single u Range National Instruments Corporation 7 3 Introduction to NI ELVIS Lab7 LEDs to the Rescue Introduction to NI ELVIS In the reverse bias direction the display shows the open circuit value 3 5 V and displays the word Open as shown in the following figure aE NATIONAL INSTRUMENTS v V0 A AX O 44 ot pe 2 Function Range Auto m an Nua Run Single sa ae Run this test to see these results The way this works is that the display shows the voltage required to generate a small current flow of about 1 mA In the forward bias region this voltage level is small and related to the materials used in the manufacture of the diode In the reverse bias direction no current flows and the tester displays the open circuit voltage about 3 5 V End of Exercise 7 1 7 4 ni com Exercise 7 2 Lab7 LEDs to the Rescue Characteristic Curve of a Diode The characteristic curve of a diode that is a plot of the current flowing through the device as a function of the voltage across the diode best displays its electronic properties Complete the following steps to display the characteristic curve of a diode 1 Place the silicon
17. measure the values of the individual circuit components 1 6 Launch NI ELVIS 2 Select Digital Multimeter 3 Use DMM Q to measure the resistors 4 5 Fill in the following information Use DMM C to measure the capacitors R Q 10 kQ nominal Rr Q 100 kQ nominal Ci uF 1 uF nominal Ch uF 0 01 uF nominal Close the DMM End of Exercise 4 1 4 2 ni com Lab4 Op Amp Filters Exercise 4 2 Frequency Response of the Basic Op Amp Circuit Complete the following steps to build and perform measurements on an Op Amp circuit 1 On the workstation protoboard build a simple 741 inverting Op Amp circuit with a gain of 10 as shown in the following schematic diagram Ry WW 15V Ry V4 To FUNCOUT Www p ear 741 L_ To CHA 4 15V T To CHA The following figure shows what the circuit looks like on the NI ELVIS protoboard ser e eee nee ee nene rrrrrrrin QA eacaaaa oe e Ae LE E E E eet le a s r _ _ ceeenana reret m e see m e e ca o FUNC T The Op Amp uses both the 15 V and 15 V DC power supplies These are found on the protoboard pin sockets labeled as 15V 15V and Ground 2 Connect the Op Amp input voltage V to FUNCOUT 3 Connect the Ground pin sockets National Instruments Corporation 4 3 Introduction to NI ELVIS Lab4 Op Amp Filters 4 Connect the Op Amp output volta
18. name Devl Ensure that the DAQ device to which the NI ELVIS workstation connects is configured in NI DAQmx as Dev as follows 1 Open Measurement amp Automation Explorer MAX 2 Under My System expand Devices and Interfaces 3 Expand NI DAQmx Devices 4 Find the DAQ device to which the NI ELVIS workstation connects and rename it Dev1 by right clicking the device and selecting Rename from the list if it currently has a different name 5 Close MAX National Instruments Corporation vil Introduction to NI ELVIS NI ELVIS Workspace Environment The NI ELVIS environment consists of the following components e Hardware workspace for building circuits and interfacing experiments e NI ELVIS software created in LabVIEW which includes the following Soft front panel SFP instruments LabVIEW ELVIS API The NI ELVIS software includes additional LabVIEW VIs for custom control and access to the features of the NI ELVIS benchtop workstation National Instruments Corporation 1 1 Introduction to NI ELVIS Lab1 NI ELVIS Workspace Environment Goal These exercises introduce the NI ELVIS workstation and demonstrate how you can measure electronic component properties You can build circuits on the protoboard and later analyze them with the NI ELVIS software suite of LabVIEW based SFPs or software instruments These exercises also demonstrate the use of NI ELVIS within the LabVIEW programming enviro
19. panel shown in the following figure to view the program flow Initialize Array F fp lumber of Data Points Bit Bundle ia zaz il Ek o 7 mrn Em e e Data Arra Build amp rra A rar H Measurement Volts DC v Device Name NI ELVIS DMM Initialize vi INT ELVIS Dum Close vi Ee Devi fv DMM j x DMM 4 NIELVIS DMM Configure Measurement vi INI ELVIS DMM Read vi Wait ms Plot Button b status w u ore National Instruments Corporation 6 9 Introduction to NI ELVIS LEDs to the Rescue A property of an electronic diode is that in one direction current flows easily forward biased while in the other direction current flow is blocked The simple switching nature of diodes an OFF state and an ON state yields many interesting analog and digital circuits Goal This lab focuses on using NI ELVIS to illuminate diode properties diode test methods bit patterns for a two way stop light intersection and the use of NI ELVIS APIs in a LabVIEW program to run the stoplights automatically National Instruments Corporation 7 1 Introduction to NI ELVIS Lab7 LEDs to the Rescue Soft Front Panels Used in This Lab This lab requires the following SFPs e Digital Diode tester DMM e Two wire Current Voltage Analyzer e Digital Writer Components Used in This Lab This lab requires the following components e Sili
20. probably blown Refer to the NI ELVIS User Manual for fuse replacement information If the protection board uses a resettable circuit for the power a dim LED indicates a potential short in the circuit If your protection board has resettable fuses power cycle the NI ELVIS to reset the resettable fuses 6 Move the front panel leads back to the DMM VOLTAGE inputs and select DMM V 7 Connect the DMM front panel leads to V and measure the input voltage using the DMM V According to circuit theory the output voltage V is as follows eel ee 1 R R 8 Using the previously measured values for R R gt and V calculate V Next use the DMM V to measure the actual voltage V V calculated V measured 9 How well does the measured value agrees with the calculated value End of Exercise 1 2 Introduction to NI ELVIS 1 6 ni com Lab1 MI ELVIS Workspace Environment Exercise 1 3 Using the DMM to Measure Current According to Ohms law the current I flowing in the previous circuit is equal to V R gt 1 Using the measured values of V and R calculate the current 2 Perform a direct measurement by moving the external leads to the workstation front panel DMM Current inputs HI and LO 3 Connect the other ends to the circuit as shown in the following figure I To 5V lt _e _ Vo R4 1 0 KQ V R 2 2 kQ To Ground q e To DMM Current Pi To DMM Current HI
21. resulting tone burst signal from the FGEN can radiate the message to the world Complete the following steps to program a waveform to produce a Morse code transmission 1 From the NI ELVIS Instrument Launcher select Arbitrary Waveform The arbitrary waveform generator allows you to create unique waveforms such as Marconi s first message You can use a special program called the waveform editor to create all kinds of unique diagnostic and control waveforms 2 Click the Waveform Editor button to link you to this program National Instruments Corporation 9 7 Introduction to NI ELVIS Lab9 RF Wireless Communication 3 Note 6 Introduction to NI ELVIS NI ELVIS Arbitrary Waveform Generator NATIONAL INSTRUMENTS Output Settings Update Rate 1000 0 s s Trigger Source Immediate v Play Stop All gt e DACO Waveform Name 1 sine1000 wdt x CLEAR Waveform Name Gain DACO Play Stop 1 00 DAC1 Gain lt empty gt 10 4 a The Arbitrary Waveform SFP provides waveform control over the DACO and DAC1 outputs Click the browse icon next to the DACO Waveform Name box From the waveform menu select 1VSine1000 wdt file When you click the DACO Play Stop button a 1 0 V amplitude sine wave at 1 000 Hz is applied to the DACO pin socket Connect the oscilloscope Channel A input to the DACO pin socket Click the DACO Play Stop button and observe a 1 KHZ sine wa
22. source to the output of the function generator Connect the output of the phototransistor to ACHO pin sockets Taken together these circuits form a simple optical data link The following figure shows this circuit on the NI ELVIS protoboard Close any SFPs End of Exercise 8 2 National Instruments Corporation 8 7 Introduction to NI ELVIS Lab8 Free Space Optical Communication Exercise 8 3 Free Space IR Optical Link Analog Complete the following steps to observe the transmitted and received signal of a free space IR optical link 1 8 From the NI ELVIS Instrument Launcher select Function Generator and Oscilloscope The function generator provides the analog signal to be transmitted The oscilloscope monitors the input signal CH A Select FUNC_OUT and the output signal CH B Select ACHO To transmit an analog signal on the LED it is necessary to bias the LED into the linear region with a voltage greater than the critical voltage Make sure the function generator is not set for Manual mode on the front panel workstation On the FGEN SFP set the offset voltage to 1 5 V Set the following parameters on the FGEN SFP e Amplitude 0 5 V e Voltage 1 5 V e Waveform Sine e Frequency 1000 Hz Run the function generator and oscilloscope and observe the transmitted and received signals Change the offset voltage and amplitude levels When the received sine wave Starts to distort the transmi
23. to a phototransistor detector Several modulation schemes including amplitude modulation and Non Return Zero NRZ digital modulation are featured National Instruments Corporation 8 1 Introduction to NI ELVIS Lab 8 Free Space Optical Communication Soft Front Panels Used in This Lab This lab requires the following SFPs e Two Wire I V Analyzer e Three wire I V Curve Tracer e Function Generator e Oscilloscope e Digital Writer Components Used in This Lab This lab requires the following components e 220 Q resistor red red brown e 470 Q resistor yellow violet brown e 1kQ resistor brown black red e 22kQ resistor red red orange e 0 01 uF capacitor e IR Emitter LED e IR Detector photoresistor e 2N3904 NPN transistor e 555 Timer chip 1 The RS276 142 IR Emitter and Detector pair are available at www radioshack com Introduction to NI ELVIS 8 2 ni com Lab8 Free Space Optical Communication Exercise 8 1 A Phototransistor Detector Understanding how a phototransistor works starts with understanding transistor characteristic curves A transistor is basically a current controlled current amplifier A small base current controls the current flowing through the transistor from the collector to the emitter Complete the following steps to use a phototransistor to develop characteristic curves current curves at different base voltages 1 Insert a 2N3904 transistor into the pin s
24. tone burst of 40 KHz square waves while a LO level is signaled by the absence of any signal The tone burst is generated using the 555 Timer circuit shown in the following figure A digital switch is connected to pin 4 RESET so that when the switch is HI a tone burst is generated When the switch is LO no oscillations occur Introduction to NI ELVIS To Digital Write Line Vec gt 5 V 1 0 kQ 3 Ra 8 4 Transmitter Detector 3 m 5 V 7 IR LED K Phototransistor 10 0 kQ 3 Rg 6 555 2 H aC 220 Q 470 Q 3 To ACHO m ea S GND mie GND To demonstrate the modulation scheme use a 1 0 kHz tone burst so it is easier to view with the oscilloscope Complete the following steps build a gated oscillator 1 Build a gated oscillator using a 555 timer chip and the following components Ra 1 0kQ e Rg 10 0 KQ e C 0 1 uF Connect pin 4 on the 555 timer chip to the digital line DO 0 output parallel port on the NI ELVIS protoboard Connect the oscillator output pin 3 to the IR LED transmitter power source Connect the output of the detector circuit to ACHO pin sockets 5 Connect pin 1 of the 555 timer chip to the ground 8 10 ni com Lab 8 Free Space Optical Communication 6 From the NI ELVIS Instrument Launcher select the Oscilloscope and Digital Writer 7 For the oscilloscope select CHANNEL A Source as ACHO Use the Channel A analog tr
25. 25 0 O 1 1 0 0 00010100 20 T2 5 0 1 O 1 0 0 T3 25 1 0 O0 0 0 1 T4 5 1 0 0O 1 0 0 Bit number R red Y yellow and G green Introduction to NI ELVIS 11 Use the Digital Writer to determine what 8 bit code needs to be written to the digital port to control the stop lights in each of the four timing intervals For example T1 requires the code 00101000 Computers read the bits in the reverse order least significant bit on the right The above code then becomes 00010100 In the previous table you can read the radix of the switch pattern in binary 00010100 decimal 20 or hexadecimal 14 7 10 ni com Lab7 LEDs to the Rescue 12 Click the white X in a gray background next to the Numeric Value to change the radix You can use this feature to determine the numeric codes for the other timing intervals T2 T3 and T4 Now if you output the 8 bit code for each of the timing intervals in sequence you can manually operate the stoplights Repeating this four cycle sequence automates to the intersection End of Exercise 7 3 National Instruments Corporation 7 11 Introduction to NI ELVIS Lab7 LEDs to the Rescue Exercise 7 4 Automatic Operation of the Two Way Stoplight Intersection Complete the following steps to automate the timing cycle on the stoplight circuit 1 Close NI ELVIS and launch LabVIEW 2 Open the program StopLights vi There is only one control on the SFP a Boolean switch used to stop the ope
26. 3 Exercise 9 2 Th Recevet nn n aa TAE Raa 9 4 Exercise 9 3 Testing the RF Transmitter and Receiver eeeeeeerereeeererrsee 9 5 Exercise 9 4 Building a Unique Test Signal with the Arbitrary Waveform Analyzer seseseseesseesseesseeseeeessetsstesstesseesseeesseeessreseessees 9 7 Exercise 9 5 A Demonstration of Marconi s RF Transmission Signal 9 10 FOE PUrener Exploration nen n aces a e SE E AE 9 11 Lab 10 Mechanical Motion Goal ao E E EIRE e REA Ne ne O E E ERER 10 1 Soft Front Panels Used in This Lab seeeseeesseeesesssesssseessseesseessensserssseeesseessresseessee 10 2 Components Used in This Lab sessessesssessseeessseesseessressersseresseessstsseesseresseeesseesseesse 10 2 Exz rcise 10 1 Start Your BW Sine saris csnsasyacbecssandcnadedesdaneas gie e i a an 10 3 Bxercise 10 2 Th Taconic er caniin hnn a e aia iterates 10 4 Exercise 10 3 Building a Rotary Motion System sessesssssessesssessserssseesssesseesee 10 6 Exercise 10 4 Testing the Rotary Motion System sessessssesssssesssessessseressseessesse 10 7 Exercise 10 5 A LabVIEW Measurement of RPM ccceescceeseceesteceesteeetteeeenes 10 8 For Further Exploration soldier a a A eee 10 10 Appendix A Additional Information and Resources National Instruments Corporation v Introduction to NI ELVIS Guide to Preparation for This Course The example programs in this course were created using the device
27. 4 Introduction to NI ELVIS 4 10 ni com Exercise 4 5 Lab4 Op Amp Filters Lowpass Filter The high frequency rolloff in the Op Amp circuit is due to the internal capacitance of the 741 chip being in parallel with the feedback resistor Ry If you add an external capacitor C in parallel with the feedback resistor Ry you can reduce the upper frequency cutoff point to fy You can predict the new cutoff point from the equation 1 BAG Complete the following steps to perform an additional frequency measurement on the Op Amp circuit 1 Short circuit the input capacitor do not remove it as you will use this in Exercise 4 6 2 Add the feedback capacitor Crin parallel with the 100 KQ feedback resistor as shown in the following figure C VVV Ry 15V Ry V4 To FUNCOUT WwWv A To CHA 15V To CHA National Instruments Corporation 4 11 Introduction to NI ELVIS Lab4 Op Amp Filters Introduction to NI ELVIS 3 Runa third Bode plot using the same scan parameters The following graph shows the high frequency response is attenuated more than the basic Op Amp response SUF NATIONAL PV INSTRUMENTS connections ACHO Signal ACH1 FGEN FUNC_OUT Gain dB 1 10 100 1000 10000 100000 Frequency Hz 4 Use the cursor function to find the high frequency cutoff point that is the frequency at which the amplitude has fallen by 3 dB o
28. 5 278 9 976 6 104 60 025 12 559 4 649 54 057 15 811 3 507 48 012 19 905 2 504 41 384 25 059 1 735 34 955 31 548 1 177 29 064 39 716 0 779 23 805 50 000 0 512 19 374 62 946 0 292 14 617 79 245 0 195 11 932 99 763 0 122 9 445 National Instruments Corporation 3 13 Introduction to NI ELVIS Op Amp Filters Adding a few capacitors and resistors to the basic Op Amp circuit yields many interesting analog circuits such as active filters integrators and differentiators Filters are used to pass specific frequency bands integrators are used in proportional control and differentiators are used in noise suppression and waveform generation circuits Goal This lab uses the NI ELVIS suite of instruments to measure the characteristics of a lowpass highpass and bandpass filter Soft Front Panels Used in This Lab This lab requires the following SFPs Digital Multimeter DMM Q C Function Generator FGEN Oscilloscope OSC Impedance Analyzer Bode Analyzer Components Used in This Lab This lab requires the following components National Instruments Corporation 10 KQ resistor R brown black orange 100 KQ resistor Ry brown black yellow 1 uF capacitor C 0 01 uF capacitor Cp 741 Op Amp 4 1 Introduction to NI ELVIS Lab4 Op Amp Filters Exercise 4 1 Introduction to NI ELVIS Measuring the Circuit Component Values Complete the following steps to
29. 7 Introduction to NI ELVIS Lab5 Digital 1 0 Exercise 5 3 Introduction to NI ELVIS Building a 4 Bit Digital Counter Complete the following steps to build a 4 bit digital counter 1 Insert a 7493 4 bit binary ripple counter into the protoboard next to the 555 digital clock circuit This chip contains a divide by two and a divide by eight counter 2 Configure the chip as a divide by sixteen counter by jumpering pin 12 Q1 to pin 1 Clock 2 on the 7493 chip as shown in the following figure Ve 3 5 V Q1 Q2 Q4 Q8 5V 4 8 C2 R 3 555 Discharge 3 C1 Rg 3 Threshold Output Clock Input 2 Trigger Cs GLAIF Oset a2 GND 7493 4 Bit Binary Counter 3 On the 7493 binary counter chip connect 5 V power to pin 5 and ground to pin 10 4 Ensure that the Oset and pins 2 and 3 are grounded 5 Connect the outputs Q1 Q2 Q4 and Q8 to the LED and digital input 9 ports of the NI ELVIS protoboard using the following mapping scheme e QI pin 12 to LED 4 and DI 4 e Q2 pin 9 to LED 5 and DI 5 e Q4 pin 8 to LED 6 and DI 6 e Q8 pin 11 to LED 7 and DI 7 e 555 Clock pin 3 to LED 0 and DI O Connect the 555 digital clock output pin 3 to the 7493 clock1 input pin 14 Power on the chips and watch the binary counts accumulate on the LEDs From the NI ELVIS Instrument Launcher select Digital Reader This allows you t
30. Corporation 3 11 Introduction to NI ELVIS Lab3 AC Circuit Tools ACH1 ACH0 31 ko To Ground ACH1 1 uF amp ACHO 3 Verify that the circuit is connected as shown in the previous figure and click the Run button ELVIS Bode Analyzer NATIONAL INSTRUMENTS Settings Frequency Hz Start 10 00 Stop 5000 00 FGEN FUNC_OUT Peak Amplitude 20 AKR Steps 10 g per decade Op Amp Signal Polarity Normal v Loa Display Y Scale Phase w Cursors Maximum 180 0 gt Minimum 180 0 Position 4 Use the Display options to select the graphing format and use the cursors to read points off the frequency characteristic frequency where the phase is 45 degrees End of Exercise 3 4 Introduction to NI ELVIS 3 12 Note The frequency where the signal amplitude has fallen to 3 dB is the same ni com Lab3 AC Circuit Tools For Further Exploration Both the Oscilloscope and Bode Analyzer SFPs have a Log button When activated the data presented on the graphs is written to a spreadsheet file on the hard drive For further analysis you can read this data with Excel LabVIEW DIAdem or another analysis or plotting program The following figure shows a sample log file 11 07 2003 4 09 PM Amplitude 2 00 V Frequency Hz Gain dB Phase dig 5 000 11 313 73 929 6 295 9 341 69 780 7 924 7 661 6
31. E a A a Ea E ia E E a oats 1 2 Exercise 1 1 Measuring Component Values 00 eee eeseeseeeeneecneeceneeeseeeeaeessaeens 1 3 Exercise 1 2 Building a Voltage Divider Circuit on the NI ELVIS Protoboard 1 5 Exercise 1 3 Using the DMM to Measure Current sesssseesseessesseesseseessressees 1 7 Exercise 1 4 Observing the Voltage Development of an RC Transient Circuit 1 8 Exercise 1 5 Visualizing the RC Transient Circuit Voltage 1 10 For F rther Exploration esien ena E E EA E Senses E 1 13 Lab 2 Digital Thermometer Go brngonpyonpranme aia e beatin dan aaa E EIA OA AA TN 2 1 Soft Front Panels Used in This Lab esseseseseseesesesessessessresressersresresstesreseeeseesseseessee 2 2 Components Used an This Labis esii nine s 2 2 Exercise 2 1 Measuring the Resistor Component Values ee ceeeeeeeeseeeeeeee 2 3 Exercise 2 2 Operating the Variable Power Supply sesssssssssssssesssessseresssesseess 2 4 Exercise 2 3 Building a Thermistor Circuit for DAQ Operation ee 2 6 Exercise 2 4 Building an NI ELVIS Virtual Digital Thermometer 0 000 00 2 8 BOE Further Exploratioi sss e e s a ee ae r a eeaalesteonnee 2 11 Lab 3 AC Circuit Tools Go hniosutiu enn a e a A A E A reiecummsraaomuatane 3 2 Soft Front Panels Used in This Lab essesesesseseesesssesressessresressernresrenseeseesrrrsresseseeesee 3 2 Conmiponents Used w This Labreche n a a E O eee eas 3 2 Exercise 3 1 Measuring the Circuit Component Valu
32. F nominal 3 Note If you are using an electrolytic capacitor be sure to connect the lead of the capacitor to the DMM current input and click the electrolytic button of the DMM C End of Exercise 1 1 Introduction to NI ELVIS 1 4 ni com Lab 1 NMI ELVIS Workspace Environment Exercise 1 2 Building a Voltage Divider Circuit on the NI ELVIS Protoboard Complete the following steps to build a voltage divider 1 Using the two resistors R and R3 assemble the following circuit on the NI ELVIS protoboard To 5V V R 10k Vy Ro To DMM Voltage HI To Ground lt e Common amp To DMM Voltage LO 2 Connect the input voltage V to the 5V pin socket 3 Connect the common to the NI ELVIS Ground pin socket 4 Connect the external leads to the DMM voltage inputs HI and LO on the front panel of the NI ELVIS workstation 3 Note NI ELVIS has separate input leads for voltage and impedance current measurements 5 Check the circuit and then apply power to the protoboard by switching the Prototyping Board Power switch to the up position The three power indicator LEDs 15V 15V and 5V should now be lit y 15V 9 ISV d lt 5v National Instruments Corporation 1 5 Introduction to NI ELVIS Lab1 NI ELVIS Workspace Environment B Notes If any of these LEDS are not lit while the others are lit and your protection board is the fused type the fuse for that power line is
33. IS Variable Power Supplies Bode Analyzer Dynamic Signal Analyzer Arbitrary Waveform Generator Digital Reader Digital Writer Impedance Analyzer Two Wire Current Voltage Analyzer Three Wire Current Voltage Analyzer Launch LabVIEW tal v 2 0 Initializing C National Instruments Corporation 1 3 Introduction to NI ELVIS Lab NI ELVIS Workspace Environment 4 Select Digital Multimeter You can use the Digital Multimeter SFP for a variety of operations The notation DMM X is used to signify the X operation 5 A message box will open Read the message and click OK 6 Click the Null button 7 Click the Q ohm button to use the Digital Ohmmeter function DMM Q to measure R R gt and R3 Fill in the following data R Q 1 0 KQ nominal R3 Q 2 2 KQ nominal R Q 1 0 MQ nominal AA Note Ifthe Function Generator is in manual mode the resistance and capacitance buttons are grayed out On the workstation switch the manual mode of the function generator to off in order to use the buttons NI ELVIS Digital Multimeter F NATIONAL INSTRUMENTS v ve ae a a at oa 9 Function null Ohms 3M 300k PEW 3k Run Single o at at Range 8 Click the capacitor button and measure the capacitor C with DMM C using the same leads Fill in the following data C uf 1 u
34. Introduction to NI ELVIS by Professor Barry Paton Dalhousie University Course Software Version 2 0 October 2005 Edition Part Number 323777C 01 Copyright 2004 2005 National Instruments Corporation All rights reserved Universities colleges and other educational institutions may reproduce all or part of this publication for educational use For all other uses this publication may not be reproduced or transmitted in any form electronic or mechanical including photocopying recording storing in an information retrieval system or translating in whole or in part without the prior written consent of National Instruments Corporation Trademarks National Instruments NI ni com and LabVIEW are trademarks of National Instruments Corporation Refer to the Terms of Use section on ni com legal for more information about National Instruments trademarks Other product and company names mentioned herein are trademarks or trade names of their respective companies Members of the National Instruments Alliance Partner Program are business entities independent from National Instruments and have no agency partnership or joint venture relationship with National Instruments Patents For patents covering National Instruments products refer to the appropriate location Help Patents in your software the patents txt file on your CD orni com legal patents Worldwide Technical Support and Product Information ni com National Instruments Co
35. NSTRUMENTS Pattern gt a le mer Manual Pattern Action Direction shit e it 5 3 Introduction to NI ELVIS Lab5 Digital 1 0 4 After a digital pattern is set click Write green arrow to send the pattern to the parallel output port DO lt 0 7 gt which in turn are passed onto the green LEDs i Note You can set the Mode to output a single pattern or to continuously output the pattern In continuous operation the hardware is updated continuously with the current pattern displayed in software The set pattern is echoed on blue LED indicators of the Bus State on the SFP Also in the Action box SFP you can Toggle Rotate or Shift the bit pattern right or left 5 Click the Stop red box button to cease updating the port In testing digital circuits there are several patterns often used for diagnostic checks 6 Click the Pattern selector on the SFP to view the options available e Manual Load any 8 bit pattern e Ramp 0 255 Computer Instruction INC e Alternating 1 0s Computer Instruction INVERT e Walking 1s Computer Instruction SHIFT LEFT LOGIC 7 Try to output each bit pattern 8 Close the Digital Bus Writer window End of Exercise 5 1 Introduction to NI ELVIS 5 4 ni com Lab5 Digital 1 0 Exercise 5 2 555 Digital Clock Circuit You can configure a 555 timer chip together with resistors R4 Rg and capacitor C to act as a digital clock source 7 lt i J
36. V e VPS APIs Components Used in This Lab This lab requires the following components e 10kQ resistor R brown black orange e 10kQ thermistor Ry Introduction to NI ELVIS 2 2 ni com Exercise 2 1 Lab2 Digital Thermometer Measuring the Resistor Component Values Complete the following steps to observe the change in resistance across a thermistor 1 Launch NI ELVIS 2 Select Digital Multimeter and click the Q button 3 Connect the test leads to DMM CURRENT 4 Insert the 10 kQ resistor and the thermistor into the prototype board 5 Connect the DMM and probes to the 10 KQ resistor and the thermistor individually and measure the component values 6 Fill in the following chart 10 kQ resistor Q Thermistor Q 7 Place the thermistor between your fingertips to heat it and watch the resistance values change The fact that the resistance decreases with increasing temperature negative temperature coefficient is one of the key characteristics of a thermistor Thermistors are manufactured from semiconductor material whose resistivity depends exponentially on ambient temperature and results in the following nonlinear response Compare the thermistor response with an RTD 100 Q platinum resistance temperature device shown in the following figure 10M 1M w Thermistor Sg N 2252 Q at 25 C 100k g 10k _ _ F i PT 100 2 oe Ik s 100 oneee eel 1o Seg T FR
37. al Byte Patterns seeeseeeeeeeseseeeesressrseresressereresrerse 5 3 Exercise 5 2 555 Digital Clock Circuit ssessssessessseeeseeessstessressresseesseressseesseese 5 5 Exercise 5 3 Building a 4 Bit Digital Counter sssssessseeesseeesseesseesseesseressseesseso 5 8 Exercise 5 4 LabVIEW Logic State Analyzer sesssessseessseeessresseessersseressseesresse 5 9 For Further Px PlOratiOn cs nne e eaa E e e O I N ESE 5 11 Lab 6 Magnetic Field Sensor COL E E E E E eaduat eaaneaisla 6 2 Soft Front Panels Used in This Lab neeenneoeseoeseeseeorssoerssssesessserssoernsosessesesessserssoo 6 2 Components Used im This Lab essciesiiii iisi tiia Es 6 2 Exercise 6 1 Testing the Analog Magnetic Field Sensor with NL ELVIS T00ls 3 4 cauiee GOA CGE i NG EEE S 6 3 Exercise 6 2 Hysteresis Characteristic of a Magnetic Field Switch 6 5 Exercise 6 3 Counting Pulses with a Magnetic Switch Sensor eee eee eeee 6 6 Exercise 6 4 Automatic Counting using a LabVIEW Program eeeeeee 6 7 BOF Further Exploration asnes rare essene oaea Tan SEa Ea ee ra iS 6 9 Lab 7 LEDs to the Rescue CO sca isis seancatencaretes dane ra e E E EE E EERENS 7 1 Soft Front Panels Used in This Labueiineiies s ia a E E dees 7 2 Components Used m This La oa cass espe as aac yu sstiaa a a eave ae sacedecbstansecev esse 7 2 Exercise 7 1 Testing Diodes and Determining Their Polarity 0 0 0 eee 7 3 Exercise 7 2 Characteristic Curve of a Diode 0 0 e
38. amed after him was equal to the vector cross product of the current and magnetic field Vy YX Bl RA En Ux H Ht et ttt _ This means that you can use a Hall probe to measure current magnetic field or the angle between the sensor axis and an external field Today integrated Hall Effect sensors have an internal constant current source and an Op Amp amplifier to buffer the output signal These sensors are inexpensive robust and can be interfaced to both analog and digital circuits National Instruments Corporation 6 1 Introduction to NI ELVIS Lab6 Magnetic Field Sensor Goal This lab focuses on using NI ELVIS tools to study the properties of Hall Effect sensors During the lab a simple Gaussmeter and a digital counter interface are built using a linear Hall Effect sensor and a Hall Effect switch respectively Soft Front Panels Used in This Lab This lab requires the following SFPs e DMM V e Oscilloscope OSC e LabVIEW VIs for the Digital Counter Components Used in This Lab Introduction to NI ELVIS This lab requires the following components e Small horseshoe magnet e Linear Magnetic Field Sensor Allegro A3240UA e Hall Effect Switch Allegro A3212UA Contact Allegro at www allegro com to request a free sample of these sensors 6 2 ni com Exercise 6 1 Lab6 Magnetic Field Sensor Testing the Analog Magnetic Field Sensor with NI ELVIS Too
39. as fallen by 3 dB This point 3 dB occurs when the impedance of the capacitor equals that of the resistor The highpass Op Amp filter equation is similar At the 3 dB point the impedance of the input resistor is equal to the impedance of the input capacitor 1 R X 21f C Ry WWW 15 V R4 C V4 To FUNCOUT wv A To CHA 15V To CHA Introduction to NI ELVIS 4 8 ni com Lab4 Op Amp Filters The following figure shows the circuit on the NI ELVIS protoboard Pet seen meen seran menee OPE manne saan aagana anne ARAARA TEPE naan aaaae 2 Runa second Bode plot using the same scan parameters as in Exercise 4 3 3 Observe that the low frequency response is attenuated while the high frequency response is similar to the basic Op Amp Bode plot We NATIONAL Pe INSTRUMENTS Connections ACHO Signal ACH1 FGEN FUNC_OUT Gain dB m o 5 ol o g T g L ET g g EIT g soroj 1 10 100 1000 10000 100000 Frequency Hz National Instruments Corporation 4 9 Introduction to NI ELVIS Lab4 Op Amp Filters 4 Use the cursor function to find the low frequency cutoff point which is the frequency at which the amplitude has fallen by 3 dB or the phase change is 45 degrees 5 Compare your results with the following theoretical prediction 1 2ni 1 RC End of Exercise 4
40. capacitor C 6 Fill in the following values Resistor R Q 1 kQ nominal Capacitor C uF 1 uF nominal 7 Close the DMM window End of Exercise 3 1 National Instruments Corporation 3 3 Introduction to NI ELVIS Lab3 AC Circuit Tools Exercise 3 2 Measuring Component and Circuit Impedance Z For a resistor the impedance is the same as the DC resistance You can represent it on a 2 D plot as a line along the x axis which is often called the real component For a capacitor the impedance or more specifically the reactance Xc is imaginary depends on frequency and is represented as a line along the y axis of a 2 D plot It is called the imaginary component Mathematically the reactance of a capacitor is represented by the following equation E joc Xc where is the angular frequency measured in radians sec and j is a symbol used to represent an imaginary number The impedance of an RC circuit in series is the sum of these two components where R is the resistive real component and Xcis the reactive imaginary component 1 Z R4 Xo R4 A Q c j C You can also represent this as a phasor vector on a polar plot with Magnitude IR EA and 1 3 Phase 0 tan A resistor has a phasor along the real X axis A capacitor has a phasor along the negative imaginary Y axis Recall from complex algebra that j J Introduction to NI ELVIS 3 4 ni com Lab3 AC Circuit Tools Complete the following
41. ce which includes access to hundreds of Application Engineers worldwide in the NI Developer Exchange at ni com exchange National Instruments Application Engineers make sure every question receives an answer For information about other technical support options in your area visit ni com services or contact your local office at ni com contact e System Integration lIf you have time constraints limited in house technical resources or other project challenges National Instruments Alliance Partner members can help The NI Alliance Partners joins system integrators consultants and hardware vendors to provide comprehensive service and expertise to customers The program ensures qualified specialized assistance for application and system development To learn more call your local NI office or visit ni com alliance If you searched ni com and could not find the answers you need contact your local office or NI corporate headquarters Phone numbers for our worldwide offices are listed at the front of this manual You also can visit the Worldwide Offices section of ni com niglobal to access the branch office Web sites which provide up to date contact information support phone numbers email addresses and current events National Instruments Corporation A 1 Introduction to NI ELVIS Appendix A Additional Information and Resources Other National Instruments Training Courses National Instruments offers several training cours
42. ce of thin but sturdy cardboard or plastic 2 Cuta slot about 0 25 in wide and 0 25 in deep near on the circumference of the disk as shown in the following figure 3 Punch or drill a small hole at the center point 4 Glue the disk to the end of the motor shaft 5 Mount the motor so the slot lines up with the IR transmitter receiver beam In operation each revolution generates one pulse 5 V GND Emitter Detector 1k 8 10k0S gt To ACH4 c VPS 12 V DC Motor End of Exercise 10 3 10 6 ni com Lab 10 Mechanical Motion Exercise 10 4 Testing the Rotary Motion System Complete the following steps to test the rotary motion system 1 Power on the protoboard and run the motor using the NI ELVIS VPS SFP to control the VPS 2 Adjust the motor position so the disk does not touch the sensor slot Observe on the oscilloscope trace the pulses generated by the rotating motor as shown below 4 Using the measurement option Channel B MEAS take the frequency measurements at a variety of power supply levels A plot of frequency versus VPS voltage demonstrates the linearity of the rotary motion system Frequencyvs VPS 200 gt N 150 100 S 50 ae 0 0 2 4 6 8 10 12 14 VPS Volts 5 Close NI ELVIS and all SFPs End of Exercise 10 4 National Instruments Corporation 10 7 Introduction to NI
43. con diode e Six light emitting diodes 2 red 2 yellow and 2 green e Six 220 Q resistors Introduction to NI ELVIS 7 2 ni com Exercise 7 1 Lab7 LEDs to the Rescue Testing Diodes and Determining Their Polarity A semiconductor junction diode is a polar device often labeled on one end with a band called the cathode the other lead is called the anode While there are many ways to indicate this polarity in the packaging of a diode one thing is always the same a positive voltage applied to the anode results in the diode being forward biased so that current can flow You can use NI ELVIS to figure out the diode polarity Complete the following steps to set up the NI ELVIS for diode and polarity tests 1 Launch the NI ELVIS Instrument Launcher and select DMM 2 Click the button 3 Connect one of the LEDs to the workstation leads DMM current HI and LO When the diode blocks the current the display shows the same value as it does when no diode is connected open circuit When the diode allows current to flow the LED gives off light and the display reads a voltage level less than the open circuit value Run current through a red LED in both directions When you see light the diode lead connected to the LO or black banana jack is the cathode You can use this simple test on other diodes to determine their polarity For a silicon rectifying diode in the forward bias direction the display shows a voltage less than 3 5 V and
44. display e Meter e Thermometer Often only one or two display formats are required when performing measurements with NI ELVIS However adding a logging feature makes it possible to observe the temperature trend In DT Logger vi found in the Hands On NI ELVIS VI Library folder a chart on the front panel is added You can add this feature as a single LabVIEW control Waveform Chart on the front panel found by selecting the Controls Graph menu From the Hands On NI ELVIS VI Library folder load and view DT Logger vi End of Exercise 2 4 2 10 ni com Lab2 Digital Thermometer For Further Exploration You can use NI ELVIS VPS with workstation front panel controls SFPs or within a LabVIEW program to build a custom instrument There are many other features you can add to the digital thermometer program such as a Hold Update button with which you can sample and hold the current value on a digital display By toggling a button you can update the temperature Open the Sample_HoldThermometer VI from the Hands on ELVIS Library folder to see how this feature is implemented in LabVIEW You can also plot AT versus time to determine the reference temperature National Instruments Corporation 2 11 Introduction to NI ELVIS AC Circuit Tools Many electronic circuits contain alternating current AC Designing good circuits requires tools used to measure components and impedance and the tools to display circuit properties With g
45. e Connect the workstation front panel BNC connector CH A to the output signal from the Hall Effect switch pins 3 and 2 On the oscilloscope panel e Select Channel Source BNC Board CH A and the following Source CH A Type Analog Slope Rising Level 2 V Observe the Hall voltage on channel A as you rapidly move the magnet toward and away from the sensor With the oscilloscope trace on a long time base 100 ms div you can observe the pulse train An angle shaft encoder a tachometer and a dwell sensor all use magnetic switches to generate pulses Counting pulses accumulates events Counting pulses within a select time interval measures frequency Next you will use a LabVIEW VI to count pulses generated by the sensor 7 Close all SFPs and remove the voltage probe End of Exercise 6 3 Introduction to NI ELVIS 6 6 ni com Lab6 Magnetic Field Sensor Exercise 6 4 Automatic Counting using a LabVIEW Program Complete the following steps to perform an automatic counting operation using a LabVIEW VI 1 Connect the output of the Hall Effect switch to the following NI ELVIS counter inputs e Hall Output pin 3 to CTRO_SOURCE e Hall Ground pinl to GROUND 2 Launch LabVIEW 3 From the Hands On NI ELVIS Library folder select Ha11 Counter vi This simple program allows you to accumulate counts as a magnetic field is passed in and out from the Hall effect switch Dividing the accumulated cou
46. e Analyzer 2 Connect the signals input V and output V to the analog input pins as follows e V ACH1 from the FUNCOUT Ground ACH1 Vout ACHO from the Op Amp Output Ground gt ACHO 3 From the Bode Analyzer set the scan parameters as follows e Start 5 Az e Stop 50000 Hz e Steps 10 per decade 4 Click Run and observe the Bode plot for the Inverting Op Amp circuit Observe the phase response Introduction to NI ELVIS 4 6 ni com Lab4 Op Amp Filters The gain is flat until approximately 10 000 Hz where it starts to roll off as shown in the following graph This graph is as expected because the high frequency response of an Op Amp depends on the circuit gain in the high frequency limit For this lab take this curve as the basic Bode plot for a 741 Op Amp Connections ACHO Signal ACH1 FGEN FUNC_OUT 1 10 100 1000 10000 100000 Frequency Hz End of Exercise 4 3 National Instruments Corporation 4 7 Introduction to NI ELVIS Lab4 Op Amp Filters Exercise 4 4 Highpass Filter Complete the following steps to modify the Op Amp circuit and perform a frequency measurement 1 Adda 1 uF capacitor Cin series with the 1 KQ input resistor R in the Op Amp circuit as shown in the following figure The low frequency cutoff point f is given by the equation 1 2nf RC where f is measured in Hertz The low frequency cutoff point is the frequency where the Gain dB h
47. e Analyzer window End of Exercise 3 2 Introduction to NI ELVIS 3 6 ni com Lab3 AC Circuit Tools Exercise 3 3 Testing an RC Circuit with the Function Generator and Oscilloscope Complete the following steps to build and test an RC circuit 1 On the workstation protoboard build a voltage divider circuit using a 1 uF capacitor and a 1 KQ resistor 2 Connect the RC circuit inputs to FUNCOUT and Ground pin sockets as shown in the following figures 4 To FUNCOUT lt _____e 1uF To Ground lt ______ National Instruments Corporation 3 7 Introduction to NI ELVIS Lab3 AC Circuit Tools The power supply for an AC circuit is often a function generator which you can use to test the RC circuit 3 From the NI ELVIS Instrument Launcher select Function Generator i gt NI ELVIS Function Generator NATIONAL INSTRUMENTS MANUAL MODE Frequency Waveforms olr Peak Amplitude DC Offset 500 Hz 8 A a j ie 0 07 25 4 5 4 5 250 kHz 1799 80 Hz 1o BE 0 04 v The FGEN SFP has the following controls which you can use to do the following e set the Frequency by decades Course and by Hz Fine e select the waveform type Sine Square or Triangle e select the waveform amplitude All of these controls are also available on the workstation front panel You can select them by sliding the workstation front panel funct
48. e Ny 0 00 RESET Se Le JE Introduction to NI ELVIS 2 4 ni com Lab2 Digital Thermometer 6 Slide the workstation switch for VPS down not Manual Now you can use the virtual VPS controls on the computer screen 7 Click and drag the virtual knob to change the output voltage 3 Notes The RESET button quickly resets the voltage back to 0 VPS works in a manner similar to VPS except the output voltage is negative when using VPS End of Exercise 2 2 National Instruments Corporation 2 5 Introduction to NI ELVIS Lab2 Digital Thermometer Exercise 2 3 Building a Thermistor Circuit for DAQ Operation Complete the following steps to build and test a thermistor circuit 1 On the workstation protoboard build a voltage divider circuit using the 10 kQ resistor and a thermistor The input voltage is wired to VPS and Ground sockets Measure the voltage across the thermistor with the DMM V and workstation leads To VPS To DMM Voltage HI Thermistor To Ground lt To DMM Voltage LO Figure 2 2 Thermistor Circuit Make sure the workstation VPS knob is set CCW 0 V position and the slide switch is set to Manual Power on the protoboard and observe the voltage levels on the DMM V As you increase the voltage from 0 to 5 V the voltage across the thermistor Vz should increase to about 2 5 V 5 Reduce the power supply voltage to 3 V 6 Heat the the
49. eed of the motor Coupling the motor and tachometer with a LabVIEW program brings computer automation to the system National Instruments Corporation 10 1 Introduction to NI ELVIS Lab 10 Mechanical Motion Soft Front Panels Used in This Lab This lab requires the following SFPs e Variable Power Supply VPS e Oscilloscope OSC e LabVIEW Components Used in This Lab This lab requires the following components e 1 KQ resistor brown black red e 10kQ resistor brown black orange e IR LED Phototransistor module e DC motor e Small punch or drill e Glue e Several combs with varying numbers of teeth per inch Introduction to NI ELVIS 10 2 ni com Exercise 10 1 Start Your Engine Lab 10 Mechanical Motion You can inexpensively purchase a small DC motor such as the Radio Shack SR65S DC These motors require a voltage source from 0 to 12 V producing a maximum RPM of about 15 000 at 12 V With no load the current requirement is about 300 mA NI ELVIS VPS can supply up to 500 mA at 12 V Also by changing the polarity of the applied voltage you can change the direction of rotation Complete the following steps to install and run a motor on the NI ELVIS protoboard 1 Connect a DC motor to the VPS output terminals supply and ground 2 Launch the NI ELVIS Instrument Launcher and select Variable Power Supply gt NI ELVIS Variable Power Supplies SUPPLY Voltage MANUAL
50. eeeeeeeeeneecneeceeeeseeeeneeenaeens 7 5 Introduction to NI ELVIS iv ni com Contents Exercise 7 3 Manual Testing and Control of a Two Way Stoplight PIGS CCV naea aun e ESE Ei ESEAS 7 8 Exercise 7 4 Automatic Operation of the Two Way Stoplight Intersection 7 12 For Further EXploration sca raa a awe teases eens owiieund aa E ae ease 7 14 Lab 8 Free Space Optical Communication Cor EA eR PRE RCI E COSIT ROP APS SEROE PY SRO E E ROPER TOO 8 1 Soft Front Panels Used in This Gab i ccc ssicisssccasscansdaxcveveicnsesededasabestaceosendonvnateoanettededes 8 2 Components Used in This Loa cg esces cesta scutes iotpaspniceuns tao ecadunecateacessehe sacs aves Bans 8 2 Exercise 8 1 A Phototransistor Detector 0 eecceeesceceeececeeeeeceeeeeceeeeecseeeeneeeees 8 3 Exercise 8 2 Infrared Red Optical Source o 7 s03 06sosteas fg eceenets whee wanes 8 6 Exercise 8 3 Free Space IR Optical Link Analog eeeceeeeeeeeeeeeeeeteeeeeneeeees 8 8 Exercise 8 4 Amplitude and Frequency Modulation Analog s es 8 9 BOE Further Exploration wesc csssareycdsavet rn nen a n tiae a n ega e aha 8 10 Lab 9 RF Wireless Communication OO a sorene ai E E E R a a oS 9 2 Soft Front Panels Used in This Lab neeessesseessesssesssseessseesseessessseresseessseesseessesssee 9 2 Components Used in This Lab sacezsecasscasesasceasscodoasnasaserasaceeeeasctaecasaamevssaicsnestecesetes 9 2 Exercise 9 1 The Transmitter charra tee E R E EEE ORE EAE 9
51. ent DMM and showed how you can use the workstation front panel connectors shown in the following figure for the DMM measurements NI ELVIS CURRENT VOLTAGE Pe PLITUDE However you are not restricted to using only these four DMM inputs You can also use the four DMM inputs present on the protoboard strip sockets National Instruments Corporation 1 13 Introduction to NI ELVIS Digital Thermometer A thermistor is a 2 wire device manufactured from semiconductor material It has a nonlinear response curve and a negative temperature coefficient Thermistors make excellent sensors for measuring temperature over a wide dynamic range They are also useful in temperature alarm circuits Goal This lab introduces the NI ELVIS variable power supply You can use it with the workstation front panel controls with the virtual controls on the computer screen or embedded inside a LabVIEW program The VPS is used to excite a 10 kQ thermistor in a voltage divider circuit The voltage measured across the thermistor is related to its resistance which in turn is related to its temperature This lab demonstrates how LabVIEW controls and indicators are used with NI ELVIS APIs to build a digital thermometer National Instruments Corporation 2 1 Introduction to NI ELVIS Lab2 Digital Thermometer Soft Front Panels Used in This Lab This lab requires the following SFPs e Digital Ohmmeter DMM Q e Digital Voltmeter DMM
52. es seeseeceeeeeeeeeesreereree 3 3 Exercise 3 2 Measuring Component and Circuit Impedance Zo eee eeeee 3 4 Exercise 3 3 Testing an RC Circuit with the Function Generator ANG OS CUIOSCODE rne o e a A s ea e a a aas 3 7 Exercise 3 4 The Gain Phase Bode Plot of the RC Circuit 3 11 For Further Explorations e a e a a e N E 3 13 National Instruments Corporation iii Introduction to NI ELVIS Contents Lab 4 Op Amp Filters Goal esheets St te irate A hi ae aa antes tate h niet ALD Re Ge ential oie ae 4 Soft Front Panels Used in This Lab ii c2hu nyc ninwn uns dodanie aes 4 1 Components Used in This LabDssrsecirige eeaeee a rae ee E E E Eesi 4 1 Exercise 4 1 Measuring the Circuit Component Values ccceeeceeeseeeeeteeeeees 4 2 Exercise 4 2 Frequency Response of the Basic Op Amp Circuit 4 3 Exercise 4 3 Measuring the Op Amp Frequency Characteristic eeeeeeeeeee 4 6 Exercise 4 4 Highbpass Pultetis iiecccscsssesasyscasteesseededeasestancoandedassacs ec iasaassdauecassdaneacdseie 4 8 Exercise 4 9 Lowpass Filter sisser e ea a a a a Eat 4 11 Exercise 4 6 Bandpass Filter ssiissciacevascisacaisavecvads segs secusnncaseastegadeaavonadevanossuonsveeans 4 13 For F rthet TSOP ALON a e EEEE E EE RE TA od Seeds RE 4 15 Lab 5 Digital 1 0 CO cca enra E E T ATE RE E R EINS 5 2 Sotti Front Panels Usedin This ab sass ia Gne a a E TR 5 2 Components Used in This Labas artise deed ie a e 5 2 Exercise 5 1 Visualizing Digit
53. es for NI ELVIS users These courses continue the training you received here and expand it to other areas Visit ni com training to purchase course materials or sign up for instructor led hands on courses at locations around the world National Instruments Certification Earning an NI certification acknowledges your expertise in working with NI products and technologies The measurement and automation industry your employer clients and peers recognize your NI certification credential as a symbol of the skills and knowledge you have gained through experience areas Visit ni com training for more information about the NI certification program NI ELVIS Resources You can find additional information about NI ELVIS at ni com academic Introduction to NI ELVIS A 2 ni com
54. g the program and passing any error messages onto the front panel INI ELVIS DIO Initialize vi PINT ELVIS DIO Read vi INI ELVIS DIO Close vi DI Introduction to NI ELVIS The 4 bit logic state analyzer samples the NI ELVIS parallel port NI ELVIS DIO Read vi and presents the bits as a numeric number blue line LabVIEW converts the numeric number into an 8 bit Boolean array thick green line Bit 4 on the port Q1 is mapped to the fifth element index 4 of the array The Index Array VI extracts a particular bit for example index 4 and sends Q1 to the Trace 0 and then onto the plot routine Each Boolean bit is converted back to a numeric value either 0 or 1 and then bundled together with the other traces for plotting the timing diagram for Q1 Q2 Q3 and Q4 The many formats of LabVIEW chart options allow the data presentation in an expected format for a timing diagram End of Exercise 5 4 5 10 ni com Lab 5 Digital 1 0 For Further Exploration If you are using a 74393 IC 8 bit binary counter you can modify the previous LabVIEW program to build an 8 bit logic state analyzer National Instruments Corporation 5 11 Introduction to NI ELVIS Magnetic Field Sensor In 1879 Edwin Hall discovered that when a current flows through a block of semiconductor material in the presence of a magnetic field a voltage is generated across it He found that this voltage now n
55. ge V to the oscilloscope input pin sockets CHA and CHA 5 From the NI ELVIS Instrument Launcher select Function Generator and Oscilloscope 6 On the Oscilloscope SFP set CHANNEL A Source to BNC Board CH A To view the input signal set CHANNEL B Source to FGEN FUNC_OUT 3 Note This shortcut on channel B allows you to link the channel B input to the oscilloscope without any additional wiring 7 On the function generator panel set the following parameters e Waveform Sine wave e Peak Amplitude 0 1 V e Frequency 1000 Hz e DC Offset 0 0 V 8 Check the circuit and then power on the protoboard 9 Run the FGEN and OSC continuous mode The test voltage V is shown on channel B and the Op Amp output voltage V on channel A 10 Because the test signal originates from FGEN select SYNC_OUT for the trigger source Introduction to NI ELVIS 4 4 ni com Lab4 Op Amp Filters i gt NI ELVIS Oscilloscope E z amp NATIONAL CHANNEL B INSTRUMENTS Display Display Source Source BNC Board CHA w FGEN FUNC_OUT w VERTICAL VERTICAL Position Position Scale Scale LJ 1 v Idiv J 100 my div Coupling Coupling DC DC Autoscale TIMEBASE TRIGGER Source A SYNC_OUT j Type Digital v 500 ys Vilidiv slope CURSORS Timeout Run Single Log gt i D Acquired 11 Measure the amplitude of the Op Amp input CH B and output CH A from the Oscilloscope
56. he FGEN SFP and the OSC SFP Play with the FGEN controls virtual or real and observe the changes on the oscilloscope window National Instruments Corporation 3 9 Introduction to NI ELVIS Lab3 AC Circuit Tools There are measurement options such as frequency and Amplitude P P that are accessed by clicking the MEAS buttons for either channel A or B Measurements show up at the bottom of the oscilloscope screen You can activate the cursors for channel A or B to make amplitude and time measurements 6 Connect the workstation BNC SCOPE input CH B to the 1 KQ resistor ays Note You can also use the channel B inputs on the protoboard pin sockets labeled Oscilloscope CH B and CH B The following conditions are true e The input signal is still on channel A e The output signal for the RC circuit is on channel B e The trigger is still on the FGEN SYNC_OUT e Select a Sine wave on the FGEN The ratio of the amplitude on channel B to the amplitude on channel A defines the circuit gain at a particular frequency Because there is no amplifier in the circuit the gain is less than one By looking at different frequencies you can get a feel for the frequency characteristics of the RC passive filter circuit Challenge Find the frequency for which the gain equals 4 2 On the oscilloscope screen measure the phase difference between the channel A trace and channel B trace at this frequency Can you relate this phase measureme
57. hematical equations T 1 0 04452 In R 29 95798 R i emperature C DEI hermistor R N End of Exercise 2 3 National Instruments Corporation 2 7 Introduction to NI ELVIS Lab2 Digital Thermometer Exercise 2 4 Building an NI ELVIS Virtual Digital Thermometer The digital thermometer program activates the VPS to power on the thermistor circuit It then reads the voltage across the thermistor and converts it into temperature The basic program is a variation of the Simple Variable Power Supply Application found in the NI ELVIS User Manual The following figure shows the digital thermometer diagram hermometer 4 emperature INI ELVIS VPS Close vi VPS Introduction to NI ELVIS NI ELVIS has the same Device Number usually Dev1 as the DAQ device The NI ELVIS VPS Initialization VI selects VPS Supply and then the voltage level on the power supply is set with the NI ELVIS Update VI which sets the VPS output to 3 V Measurement scaling calibration and display occur in sequence within the While Loop VoltsIn vi measures the thermistor voltage Scaling vi converts the measured voltage to resistance according the scaling equation above Convert R T vi uses a known calibration equation to convert the thermistor resistance into temperature Finally the temperature is displayed on the LabVIEW front panel in a variety of formats The Wait function of 100 mil
58. igger with a trigger level at 0 5 V In operation every time you set bit 0 DO 0 of the Digital Writer to HI a 1 0 kHz signal appears on the oscilloscope No signal is presented when Bit 0 is LO Try some of the other digital patterns like Walking 1 s or Ramp and view the modulation scheme on the Oscilloscope SFP In remote controllers the encoding scheme is slightly more complicated If you are interested in building a computer controlled IR remote transmitter to control an item such as a stereo refer to Sensors Transducers and LabVIEW by Barry E Paton for details NI ELVIS National Instruments Corporation 8 11 Introduction to NI ELVIS RF Wireless Communication Midday at Signal Hill St John s Newfoundland Canada Guglielmo Marconi pressed his ear to a telephone head set connected to an experimental wireless receiver 1 700 miles away at Poldu Cornwall England his co workers were about to send the Morse code letter S which is three dots Faintly but clearly psht psht psht pause psht psht psht came through the earphone The date was December 12 1901 and the first Trans Atlantic message has just been sent and received National Instruments Corporation 9 1 Introduction to NI ELVIS Lab9 RF Wireless Communication Goal In this lab a paper clip antenna is used to send this classic message and other waveforms over a wireless radio frequency link The NI ELVIS function generator is the transmitter
59. ion generator switch to Manual As with the Variable Power Supply manual control turns on the green LED display on the SFP and grays out the virtual controls 3 Note If you want to add a DC offset to the AC signal it is only available on the FGEN SFP Introduction to NI ELVIS 3 8 ni com Lab3 AC Circuit Tools You can use the oscilloscope to analyze the voltage signals of the RC circuit by completing the following steps 1 From the NI ELVIS Instrument Launcher select Oscilloscope The oscilloscope SFP is similar to most oscilloscopes but the NI ELVIS oscilloscope can automatically connect inputs to a variety of sources i NI ELVIS Oscilloscope NATIONAL INSTRUMENTS Timeout D Acquired en 5 ot Display Source FGEN FUNC_OUT v VERTICAL Position J Scale J 1v Coupling aag CHANNEL B Display Source FGEN SYNC_OUT v VERTICAL Position J Scale J y Coupling v idiv TIMEBASE J Source SYNC_OUT Type Digital v Slope TRIGGER CURSORS Click the CHANNEL A Source drop down list Set the Source on CHANNEL A Source on CHANNEL B TRIGGER and TIMEBASE inputs as shown in the previous figure This configuration allows the oscilloscope to measure the output of the function generator on channel A the FGEN TTL synchronization signal SYNC_OUT on channel B and be triggered with the SYNC_OUT signal 4 Click the Run button of t
60. liseconds ensures the voltage is sampled every 0 1 seconds The digital thermometer continues running until the Stop button on the front panel button is activated or an error occurs When the loop ends the supply reference is closed and the VPS is set to 0 V 2 8 ni com Lab2 Digital Thermometer Complete the following steps to open and view the components and code in the digital thermometer VI 1 From the Hands On NI ELVIS VI Library folder open Digital Thermometer vi 2 Open the program and subVIs to view the program flow and see how the subVIs and the Read and Convert functions are coded With the calibration equation for the thermistor you can update the subVI Convert R T with the proper equation and use it to have a functioning digital thermometer If you want to write your own program you can use DT Template vi found in the Hands On NI ELVIS VI Library folder and add your programming style The VPS API functions are located in Functions All Functions Instrument I O Instrument Drivers NI ELVIS Variable Power Supplies 1 All Functions Instrument I O Variable Power Supplies ei Variable Power Supplies YPS YPS VPS p fial VPS National Instruments Corporation 2 9 Introduction to NI ELVIS Lab2 Digital Thermometer Introduction to NI ELVIS The simple digital thermometer program displays the following three indicators on the front panel e Digital
61. ls The Allegro devices have three terminals V power Gnd and the Hall output Complete the following steps to install and perform measurements on a Hall Effect sensor 1 Insert a linear Hall device A3240 into the protoboard 2 Connect the power 5V pin socket to the V 3 4 Connect the DMM voltage leads to the Hall output and Ground Connect the ground pin socket to Ground L Top View Hall IC Hall Voltage to DMM Voltage HI 12 3 Ground Lead to DMM Voltage LO To 5V Hall voltage To Ground National Instruments Corporation Launch the NI ELVIS Instrument Launcher and select Digital Multimeter Bring a small magnet field intensity of several hundred gauss in close proximity to the face of the Hall sensor In the absence of a magnetic field the sensor reads one half of V or about 2 5 V As you bring the magnet closer to the sensor the Hall voltage either rises greater than 2 5 V or falls to less than 2 5 V depending on the magnet polarity The south end of the magnet causes a rise the north end a fall The sensor saturates near 5 or O V in a field in excess of 500 gauss The Hall voltage is quite nonlinear with the distance between the sensor and the magnet face To observe this relationship make distance and voltage measurements and then plot the observations The distance between adjacent pin socket holes is 0 1 in Place the magnet on the protoboard direc
62. lt in Exercise 9 2 then power on the protoboard 2 Move the receiver antenna a few millimeters away from the transmitter antenna 3 Connect the oscilloscope workstation BNC CH A inputs to the Op Amp output pin 6 and ground Typical oscilloscope settings are e Channel A ACH5 e Trigger Settings SYNC_OUT 4 Decrease the oscilloscope timebase until you see a sine wave If you cannot see a signal right away touch the two antenna tips with your fingertip This simulates the high impedance of the atmosphere and allows a small signal to propagate Adjust the FGEN amplitude and frequency until you get a good signal Measure the signal level as you separate the receiver antenna from the transmitter antenna You can easily measure the separation with a ruler You can quickly get an idea of how rapidly the signal level falls off with distance a long antenna helps in receiving distant signals Marconi at Signal Hill used a kite to carry his antenna hundreds of feet into the atmosphere to receive a better signal Now that the transmitter receiver is working it is time to duplicate Marconi s classic message Marconi s first RF transmitter consisted of a spark gap connected to a resonant circuit and a very long antenna often carried high on a balloon or kite When a spark discharged between the electrodes an intense RF pulse is generated with a short time duration of a few milliseconds It takes 30 000 V to produce a spark betwee
63. ly the threshold voltage Vy by the electronic charge e the product is energy and it is close to the band gap energy of the semiconductor material used in the manufacture of the semiconductor diode Further in the forward biased region the light from the LED has an energy of hc A where h is Planck s constant c is the speed of light and is the wavelength of the center of the energy distribution Conservation of energy yields the equation E where e is the electron charge From the LED specifications you can determine the wavelength or color of the LED For example red LEDs have a wavelength of about 560 nanometers From the I V characteristic curve of the LED shown in Exercise 7 2 you can measure the threshold voltage Vz Ifyou plot Vrversus 1 A for the three different colored LEDs you will find a straight line with a slope approximately equal to hc e a fundamental constant 7 14 ni com Free Space Optical Communication You are familiar with a number of remote controllers lying around the house such as those controlling televisions stereos and DVD players Do you know how these controllers work The secret is an infrared optical data link a type of free space optical communications link Figure 8 1 shows an example circuit on the protoboard NI ELVIS Figure 8 1 Free Space Infrared Optical Digital Communications Link Goal This lab uses an infrared optical source to communicate information over free space
64. mple the tachometer signal and provide an input signal array for Pulse Measurements vi The RPM signal is sent to a front panel meter and displayed in units of KRPM The RPM signal also goes to a shift register with five elements This provides an averaged RPM signal on the front panel The motor speed is manually controlled by the Setpoint front panel knob There is also a graph of the tachometer signal as a function of time on the front panel 3 Run Pulse Measurements vi to run the motor See and hear how responsive the motor is to a rapid change in the RPM setpoint End of Exercise 10 5 National Instruments Corporation 10 9 Introduction to NI ELVIS Lab 10 Mechanical Motion For Further Exploration Computer Automation of the Rotary Motion System National Instruments provides a proportional integral and derivative PID Toolkit included in an academic site license that has additional LabVIEW VIs to add computer automation to the rotary system These control algorithms move a system from one set point initial RPM to another set point final RPM in an optimized manner The addition of PID vi brings optimal control to the program The algorithm compares the target RPM final RPM with the current RPM averaged RPM signal to generate a DC error signal that drives the variable power supply Integration and differentiation parameters are used to adjust the VPS voltage smoothly from one measurement to the next output ra
65. n electrodes separated by 1 cm and the current can be large A single spark followed by a pause was a dot A longer spark followed by a pause was a dash Together this was all the ingredients needed for a Morse code transmission The letter S is three dots in rapid succession The letter O is three dashes in rapid succession The distress call S O S is dot dot dot dash dash dash dot dot dot National Instruments Corporation 9 5 Introduction to NI ELVIS Lab9 RF Wireless Communication For the first Trans Atlantic message Marconi chose the simpler signal dot dot dot End of Exercise 9 3 Introduction to NI ELVIS 9 6 ni com Lab9 RF Wireless Communication Exercise 9 4 Building a Unique Test Signal with the Arbitrary Waveform Analyzer A dot is a signal usually an oscillation followed by silence no signal Each part lasts for about 0 1 second A dash is a signal lasting for the duration of three dots or 0 3 second followed by a pause The encoding scheme is a simple tone burst with different duration times The letter S is encoded as dot dot dot or in binary 101010 where 1 is the dot and 0 is the pause A longer message consisting of multiple letters like SSS has a longer pause 0 4 second placed between each letter This message in binary is 101010 0000 101010 0000 101010 0000 If you can generate this waveform on the NI ELVIS Digital to Analog Converter DAC you can use the DAC output to gate the function generator The
66. nge setpoint output process variable PID gains dt out s dt s reinitialize F PID vi PID algorithm For simple PID applications or high speed control applications that require an efficient algorithm PID algorithm features control output range limiting with integrator anti windup and bumpless controller output for PID gain changes If you are more familiar with control you can use PID Autotuning vi to set the initial PID parameters automatically You can then fine tune the parameters to the specific system You can get the PID Toolkit at ni com PID CHART Introduction to NI ELVIS 10 10 ni com Additional Information and Resources This appendix contains additional information about National Instruments technical support options and NI ELVIS resources National Instruments Technical Support Options Visit the following sections of the National Instruments Web site at ni com for technical support and professional services e Support Online technical support resources at ni com support include the following Self Help Resources For answers and solutions visit the award winning National Instruments Web site for software drivers and updates a searchable KnowledgeBase product manuals step by step troubleshooting wizards thousands of example programs tutorials application notes instrument drivers and so on Free Technical Support All registered users receive free Basic Servi
67. nment Soft Front Panels Used in This Lab This lab requires the following SFPs e Digital Ohmmeter DMM Q e Digital Capacitance Meter DMM C e Digital Voltmeter DMM V Components Used in This Lab This lab requires the following components e 1 0 KQ resistor R brown black red e 2 2 KQ resistor R3 red red red e 1 0 MQ resistor R3 brown black green e 1 uF capacitor C e FET Op Amp such as an LM356 Introduction to NI ELVIS 1 2 ni com Exercise 1 1 Lab1 MI ELVIS Workspace Environment Measuring Component Values Complete the following steps to measure component values 1 Connect two banana type leads to the DMM current inputs on the workstation front panel 2 Connect the other ends to one of the resistors Launch NI ELVIS by double clicking the NI ELVIS desktop icon After initializing as shown in the figure below the suite of LabVIEW software instruments opens Note If you receive an error check to see that the DAQ device cable is securely connected and that the NI ELVIS workstation is powered on NI ELVIS may also be communicating with the incorrect DAQ device if you have multiple DAQ devices in the system If more than one DAQ device is in the system select the DAQ device used by NI ELVIS in the window that opens gt ELVIS Instrument Launcher NATIONAL SNStRuments Configure Digital Multimeter Oscilloscope Function Generator NI ELV
68. nt to the Phasor phase measurement found with the Impedance Amplifier in Exercise 3 2 Close the function generator and oscilloscope End of Exercise 3 3 Introduction to NI ELVIS 3 10 ni com Lab3 AC Circuit Tools Exercise 3 4 The Gain Phase Bode Plot of the RC Circuit A Bode plot defines in a real graphical format the frequency characteristics of an AC circuit Amplitude response is plotted as the circuit gain measured in decibels as a function of log frequency Phase response is plotted as the phase difference between the input and output signals on a linear scale as a function of log frequency Complete the following steps to build an RC circuit and measure the gain and phase Bode plots of the circuit 1 From the NI ELVIS Instrument Launcher select Bode Analyzer The Bode Analyzer allows you to scan over a range of frequencies from a start frequency to a stop frequency in steps of AF You can also set the amplitude of the test sine wave The Bode Analyzer uses the SFP function generator to generate the test waveform You must connect the FUNCOUT output sockets to the test circuit and to ACH1 The output of the circuit under test goes to ACHO You can find further information by clicking the HELP button on the lower right corner of the Bode Analyzer window 2 Rebuild the RC circuit on the NI ELVIS protoboard similar to the following circuit and make connections as shown in Exercise 3 3 d Mational Instruments
69. nts by the Elapsed count time generates the average time per count or the frequency Tick Count ms Initial Time Double click DAQ assistant to change settings c DAQ Assistant error out ino ae E National Instruments Corporation 6 7 Introduction to NI ELVIS Lab6 Magnetic Field Sensor NI ELVIS has access to the DAQ device counters and this lab uses Dev1 Counter 0 The program uses the DAQ Assistant to control the DAQ device counters Two Tick Count functions are used to measure the timing interval End of Exercise 6 4 Introduction to NI ELVIS 6 8 ni com Lab6 Magnetic Field Sensor For Further Exploration In Exercise 6 1 you manually collected data and then plotted a graph However using the NI ELVIS APIs for the digital voltmeter DMM V within LabVIEW you can build a simple program to collect the Hall data on demand in a semi automated solution Complete the following steps to use a LabVIEW to automate data collection from the Hall device 1 From the Hands On NI ELVIS Library folder select Hall Sample vi 2 Place the magnet a known distance in front of the linear Hall sensor A3240 and enter the end face position of the magnet in the Position box 3 Click the Sample button when ready This data point Position Hall Voltage is automatically entered into an array of sampled points 4 When you have finished sampling click Plot to open the graph Open the diagram
70. o monitor the binary states on the computer and at the same time view the states on the green LEDs Close NI ELVIS End of Exercise 5 3 5 8 ni com Exercise 5 4 Lab 5 Digital 1 0 LabVIEW Logic State Analyzer The exercises up to this point have only covered the state of digital outputs at one point in time This exercise shows how a timing diagram is formed by stringing sequential states together sampled uniformly in time Plotting several digital lines together on the same graphs generates a digital timing diagram as illustrated below A binary counter has a unique timing diagram where the following falling edge of the previous bit causes the next bit to toggle 250 Sample Time ston Cc Using the LabVIEW APIs for digital I O you can build a simple 4 bit logic state analyzer The Digital I O palette is located in Functions All Functions Instrument I O Instrument Drivers NI ELVIS The top row of DIO VIs from left to right are Initialize Read Write and Close Launch LabVIEW and select Binary Counter vi from the Hands On NI ELVIS Library folder National Instruments Corporation 5 9 Introduction to NI ELVIS Lab5 Digital 1 0 On the diagram panel the NI ELVIS DIO icon on the left initializes the Read function on Dev1 default and creates a refnum green line The middle DIO icon reads the port and the DIO icon on the right closes the DIO operation freeing up any memory used in runnin
71. ockets labeled 3 WIRE CURRENT HI and CURRENT LO on the protoboard as shown in the following figure ik Note CURRENT HI is the base CURRENT LO is the emitter and 3 WIRE is the collector lead 2 Launch the NI ELVIS Instrument Launcher and select Three Wire Current Voltage Analyzer 3 Power on the protoboard 4 Set the Base Current and Collector Voltage as shown in the following figure and click Run National Instruments Corporation 8 3 Introduction to NI ELVIS Lab 8 Free Space Optical Communication NI ELVIS Three Wire Current Voltage Analyzer NATIONAL INSTRUMENTS Bf a CURRENT HI E CURRENT LO Base Current Ib Settings Start Number of Curves 30 00 4 p 3 Increment 15 00 pA Collector Voltage Yc Settings Start Stop 0 00 Ay 1 00 y Increment 0 050 Sy 10 00 Mapping Voltage Current Linear Linear Position Collector Current Limit Display Autoscale Cursor caa Introduction to NI ELVIS The graph shows the Collector Current versus Collector Voltage for different values of the base current You can set many parameters for the Collector Voltage and the Base Current ranges When run this SFP first outputs the set base current then outputs the collector voltage and finally measures the collector current Data points I V are plotted and sequential points with the same base current are connected with a line You
72. ood tools and minimal circuit knowledge you can modify any circuit to give optimal response NI ELVIS Oscilloscope NATIONAL INSTRUMENTS Eee CHANNEL A CHANNEL B Display Display Source Source FGEN FUNC_OUT w FGEN SYNC_OUT v VERTICAL VERTICAL Position i Position J J Scale Scale J 2y v div J 2 v Idiv Coupling Coupling TIMEBASE TRIGGER Source Level v Immediate v ims jdiv CURSORS Timeout ed Log i Acquired orr National Instruments Corporation 3 1 Introduction to NI ELVIS Lab3 AC Circuit Tools Goal This lab introduces the NI ELVIS tools for AC circuits a digital multimeter function generator oscilloscope impedance analyzer and Bode analyzer Soft Front Panels Used in This Lab This lab requires the following SFPs e Digital Ohmmeter DMM Q C e Function Generator FGEN e Oscilloscope OSC e Impedance Analyzer e Bode Analyzer Components Used in This Lab This lab requires the following components e 1kQ resistor R brown black red e 1 uF capacitor C Introduction to NI ELVIS 3 2 ni com Lab3 AC Circuit Tools Exercise 3 1 Measuring the Circuit Component Values Complete the following steps to obtain the values of the circuit components 1 Launch NI ELVIS 2 Select Digital Multimeter 3 Connect the test leads to DMM CURRENT 4 Use the DMM Q to measure the resistor R 5 Use DMM C to measure the
73. orange 100 KQ resistor Rg brown black yellow 1 uF capacitor C 555 Timer chip 7493 4 bit binary counter 5 2 ni com Exercise 5 1 Lab 5 Digital 1 0 Visualizing Digital Byte Patterns The NI ELVIS protoboard has a bank of eight green LEDs with pin sockets LED lt 0 7 gt You can use them as visual indicators of digital logic states On HI and Off LO Complete the following steps to output digital patterns using the Digital Writer 1 Wire the LEDs to the 8 bit parallel output bus sockets pins DO lt 0 7 gt For example connect DO 0 to the pin socket LED 0 Only one lead is required because the grounds are connected internally within NI ELVIS ik Note The digital output pins are located in the upper right hand corner of the NI ELVIS protoboard 2 Launch the NI ELVIS Instrument Launcher 3 Select Digital Writer A new digital logic diagnostic window opens National Instruments Corporation which allows you to set reset any of the write lines to a HI or LO state The Digital Output DO bits are labeled 0 to 7 reading right to left in the Manual Pattern box as shown in the following figure You can set reset HI LO on any bit by clicking the top or bottom portion of the virtual switch Collectively these eight bits constitute a byte which you can read in a binary hexadecimal or decimal format in the display box above the switches i gt NI ELVIS Digital Bus Writer NATIONAL I
74. plight intersection z oO 3 4 5 8 7 au rrree Zee jA ia verre eRe anu rrer e 8 4a rrerreFr EEE eer r 4 oe eee rrr wiles s Fr rere cer a2 a b kd rrrrr zzz Re e aa rrreree zea rer i ibd rrrrr E E E ET nw or o o vy To Ground Each LED is controlled by one binary bit on the 8 bit parallel bus on the NI ELVIS protoboard Output pin sockets are labeled DO lt 0 7 gt 2 Connect the pin socket DO 0 through a 220 Q resistor to the anode of the red LED in the north south up down direction 3 Connect the other end of the LED to one end of a 220 Q resistor Sy Note The resistor is used to limit the current through the LED Introduction to NI ELVIS 7 8 ni com Lab7 LEDs to the Rescue 4 Connect the other end of the 220 Q resistor to the ground The following figure illustrates this circuit DO X Gu 220 0 National Instruments Corporation Connect the remaining colored LEDs in a similar fashion Here is the complete mapping scheme DO 0 Red N S direction DO 4 Red E W direction DO 1 Yellow N S direction DO 5 Yellow E W direction DO 2 Green N S direction DO 6 Green E W direction From the NI ELVIS Instrument Launcher select Digital Writer Using the vertical slide switches select any 8 bit pattern and output it to the NI ELVIS digital lines Recall that Bit 0 is connected to the pin socket on the protoboard labeled DO 0
75. r the phase change is 45 degrees 5 Compare your results with the following theoretical prediction 2nfy ae ee End of Exercise 4 5 4 12 ni com Lab4 Op Amp Filters Exercise 4 6 Bandpass Filter If you allow both an input capacitor and a feedback capacitor in the Op Amp circuit the response curve has both a low cutoff frequency fz and a high cutoff frequency fy The frequency range fy f is called the bandwidth For example a good stereo amplifier would have a bandwidth of at least 20 000 Hz The following figure shows a bandpass filter on the NI ELVIS protoboard To FUNC OUT Remove the short on C and run a fourth Bode plot using the same scan parameters The following graph shows the results of using the bandpass filter MF NATIONAL p l UM Connections ACHO Signal ACH1 FGEN FUNC_OUT Gain dB E FEEN TF org ELLU TT oa T Terry 1 10 100 1000 10000 100000 Frequency Hz National Instruments Corporation 4 13 Introduction to NI ELVIS Lab4 Op Amp Filters By drawing a line at 3 dB below the maximum amplitude region the frequency range contained by all frequencies above this line defines the bandpass End of Exercise 4 6 Introduction to NI ELVIS 4 14 ni com Lab4 Op Amp Filters For Further Exploration The generalized Op Amp transfer curve is given by the phasor equation Z Vout a Vin where the Impedance values for the four circuits are
76. ration of the stoplights 3 Switch to the block diagram Window Show Block Diagram 4 Observe the four cycle sequence generated by the For Loop The subVI icon with the pencil icon NI ELVIS D1IO Write is the structure that outputs the 8 bit code to the stoplights This subVI expects the code input to be a numeric number For example the first timing interval T1 requires the code 20 twenty numeric You must transfer the four 8 bit codes numeric value from the table in Exercise 7 3 into the four blank elements of the code array blue labeled Output Pattern The NI ELVIS DIO Initialize subVI on the left requires the digital port and the I O operation write Like all NI ELVIS programming structures the DIO channel must be closed by the subVI NI ELVIS DIO Close on the right after completion While Loop is stopped NI fg Dev1 7 NI ELVIS DIO Initialize vi DIO NI ELVIS DIO Close vi lo Introduction to NI ELVIS 7 12 ni com Lab7 LEDs to the Rescue The timing intervals are stored in the four elements of the Time Delay array orange To speed up operation the 25 second time interval is reduced to 5 seconds and the 5 second time interval is reduced to 1 second End of Exercise 7 4 National Instruments Corporation 7 13 Introduction to NI ELVIS Lab7 LEDs to the Rescue For Further Exploration Introduction to NI ELVIS LEDs are amazing devices If you multip
77. rmistor with your fingertips and watch the voltage decrease You can now rearrange the standard voltage divider equation to calculate the thermistor resistance as follows _ RXT T 3 volts Vz At an ambient temperature of 25 C the resistance should be about 10 KQ This equation called a scaling function allows you to convert the measured voltage into the thermistor resistance You can easily measure Vy with the NI ELVIS DMM or within a LabVIEW program VI Introduction to NI ELVIS 2 6 ni com Lab2 Digital Thermometer In LabVIEW the previous scaling equation is coded as a subVI and looks like the following block diagram Reference R VPS V q A typical thermistor response curve demonstrates the relationship between device resistance and temperature It is clear from this curve that a thermistor has the following three characteristics e The temperature coefficient AR AT is negative e The response curve is nonlinear exponential e The resistance varies over several decades refer to Figure 2 1 You can produce a calibration curve by fitting a mathematical equation to the response curve LabVIEW has many mathematical tools to fit such a relationship When the correct equation is found you can calculate the temperature for any resistance within the calibrated region The following calibration VI is typical for a thermistor and demonstrates how you can use the LabVIEW formula node to evaluate mat
78. rporate Headquarters 11500 North Mopac Expressway Austin Texas 78759 3504 USA Tel 512 683 0100 Worldwide Offices Australia 1800 300 800 Austria 43 0 662 45 79 90 0 Belgium 32 0 2 757 00 20 Brazil 55 11 3262 3599 Canada 800 433 3488 China 86 21 6555 7838 Czech Republic 420 224 235 774 Denmark 45 45 76 26 00 Finland 385 0 9 725 725 11 France 33 0 1 48 14 24 24 Germany 49 0 89 741 31 30 India 91 80 51190000 Israel 972 0 3 6393737 Italy 39 02 413091 Japan 81 3 5472 2970 Korea 82 02 3451 3400 Lebanon 961 0 1 33 28 28 Malaysia 1800 887710 Mexico 01 800 010 0793 Netherlands 31 0 348 433 466 New Zealand 0800 553 322 Norway 47 0 66 90 76 60 Poland 48 22 3390150 Portugal 351 210 311 210 Russia 7 095 783 68 51 Singapore 1800 226 5886 Slovenia 386 3 425 4200 South Africa 27 0 11 805 8197 Spain 34 91 640 0085 Sweden 46 0 8 587 895 00 Switzerland 41 56 200 51 51 Taiwan 886 02 2377 2222 Thailand 662 278 6777 United Kingdom 44 0 1635 523545 For further support information refer to the Additional Information and Resources appendix To comment on National Instruments documentation refer to the National Instruments Web site at ni com info and enter the info code feedback Contents Guide to Preparation for This Course Lab 1 NI ELVIS Workspace Environment OAT es aesivas vast s Sanaa in e a a Gadeaan a E a a p EERE GAE 1 2 Soft Pront Panels Used in THS babi c esnsttanditsnietn a e a E a 1 2 Components Used This Labe e
79. scale 7 Try the Cursor operation It gives the I V coordinate values as you drag the cursor along the trace The threshold voltage is related to the semiconductor material of the diode For silicon diodes the threshold voltage is about 0 6 V while for germanium diodes it is about 0 3 V One way to estimate the threshold voltage is to fit a tangent line in the forward bias region near the maximum current refer to the following figure At the point where the tangent intersects the voltage axis defines the threshold voltage Observe the 1 V characteristic curve for a light emitting diode The threshold Voltage VT is given by the intersection of the tangent line with the voltage axis Current m 1 1 12 13 1 1 5 volage v 19 2 0 7 6 ni com Lab7 LEDs to the Rescue 8 Using the Two Wire Current Voltage Analyzer determine the threshold voltage for a red yellow and green LED and fill in the following information Red LED V Yellow LED V Green LED V Did you observe any trend End of Exercise 7 2 National Instruments Corporation 7 7 Introduction to NI ELVIS Lab7 LEDs to the Rescue Exercise 7 3 Manual Testing and Control of a Two Way Stoplight Intersection Complete the following steps to build and manually test and control a two way stoplight intersection simulation 1 Install two each of red yellow and green LEDs on the NI ELVIS protoboard positioned as a two way sto
80. settings b isettings DAQ Assistant T DAQ Assistant2 Ty TE ED eal data EDNA error in rem rs SH eroin es eroro E Ty n 0 00 SSS kc Charging and Dischar ging o RC Charging and Discharging m M 4 NI ELVIS VPS Initialize vi NI ELVIS VPS Update vi NI ELVIS PS Update vi INI ELVIS VPS Close vi Device Name l error Dl 62 voltage DAQmx Reset Device vi Supply Y 5 00 Les National Instruments Corporation 1 11 Introduction to NI ELVIS Lab1 NI ELVIS Workspace Environment Introduction to NI ELVIS The following sequence of events occurs 1 The VPS Initialize VI on the left starts NI ELVIS and selects the power supply 2 The Update VI sets the output voltage on VPS to 5 V 3 The first sequence measures 50 sequential voltage readings across the capacitor In the For Loop the DAQ Assistant VI takes 100 readings at rate of 1 000 samples per second and passes the values to an array The array is passed to the Mean VI which returns the average value of the 100 readings The average is passed to the chart using a local variable terminal RC Charging and Discharging The next sequence sets the VPS voltage equal to 0 V 8 The last sequence measures another 50 averaged samples for the discharge cycle End of Exercise 1 5 1 12 ni com Lab MI ELVIS Workspace Environment For Further Exploration This chapter introduced the software instrum
81. steps to visualize this phasor in real time 1 Select Impedance Analyzer from the NI ELVIS Instrument Launcher menu i NI ELVIS Impedance Analyzer NATIONAL INSTRUMENTS Display Settings Measurement Frequency Visible Section Scale AN 1000 00 Hz 2 Connect leads from the front panel DMM current inputs to the 1 kQ resistor Verify that the phasor is along the real axis and the phase is zero 4 Connect the leads to the capacitor Verify that the phasor is along the negative imaginary axis and that the phase is 270 or 90 degrees 6 Adjust the Measurement Frequency control box to observe that the reactance length of the phasor gets smaller when you increase the frequency and larger when you decrease the frequency 7 Connect the leads across the resistor and capacitor in series verify the circuit is not connected to ground The circuit phasor has both a real and an imaginary component 8 Change the frequency and watch the phasor move National Instruments Corporation 3 5 Introduction to NI ELVIS Lab3 AC Circuit Tools 9 Adjust the frequency until the absolute value of the reactance component X is equal to the absolute value of the resistance component R This is a special frequency value where the phase is 45 The magnitude also has special meaning at this frequency or phase angle What is the magnitude of the phasor at this point Answer R J2 10 Close the Impedanc
82. sure the black lead is connected to the LED anode short lead Select the Two Wire Current Voltage Analyzer and set the voltage sweep parameters to e Start 0 0 V e Stop 2 0 V e Increment 0 05 V Click Run The IV curve for the infrared diode is developed and displayed PMs Positive current limit exceeded Current m INN veyperrpeeryprer Voltage v 8 6 ni com Lab8 Free Space Optical Communication In the forward bias region the IR LED emits light for voltages greater than about 0 9 V Light is emitted at a wavelength of 950 nm outside the spectral range of human eyesight and in the near infrared region The LED specs tell us that the maximum allowed current is over 100 mA making IR LEDs about 10 times brighter than normal visible LEDs This is what gives the remote controllers so much range Connecting the LED in series with a 220 Q resistor and a 5 V power supply produces a current of about 17 mA yielding about 10 mW of invisible optical power It takes a special detector like the phototransistor to see it Build the LED transmitter circuit and the phototransistor circuit on the protoboard as shown in the following figure Transmitter Detector To FUNC OUT m 5 V IR LED Y K Phototransistor gt 220 o3 470 os To ACHO GND 1 eno 7 Connect the LED power
83. tly in front of the sensor and measure the Hall voltage in 0 1 or 0 05 in increments over a distance of about 1 in 6 3 Introduction to NI ELVIS Lab6 Magnetic Field Sensor 9 Record each reading in the following table Distance in Reading Distance in Reading 0 05 0 55 0 10 0 60 0 15 0 65 0 20 0 70 0 25 0 75 0 30 0 80 0 35 0 85 0 40 0 90 0 45 0 95 0 50 1 00 10 Plot the Hall voltage versus distance The plot should be similar to the following graph The response is quite nonlinear This demonstrates the importance of knowing the operating distance between the sensor and the magnet End of Exercise 6 1 Introduction to NI ELVIS 6 4 ni com Exercise 6 2 Lab6 Magnetic Field Sensor Hysteresis Characteristic of a Magnetic Field Switch Complete the following steps to perform measurements on the Hall Effect switch to determine its hysteresis characteristics 1 4 Replace the linear sensor with the Hall Effect switch A3212 The power connections are the same as the linear circuit Repeat the measurements for Hall voltage versus distance for both an increasing and a decreasing distance Plot each graph on the same set of axes It should look similar to the following graph 7 f i g 1 j S S i ro 4 a The Hall switch is a digital sensor whose output is either HI 5 V or LO 0 8 V A critical field B ay exists above
84. tter becomes nonlinear Find the best values of offset and amplitude for a linear no distortion transmission link The link is now ready to send data Leave the function generator and oscilloscope SFPs open End of Exercise 8 3 Introduction to NI ELVIS 8 8 ni com Lab8 Free Space Optical Communication Exercise 8 4 Amplitude and Frequency Modulation Analog Complete the following steps to build an elementary free space optical communication link 1 Wire the digital to analog output pin sockets DACO and DAC1 to the function generator pin sockets on NI ELVIS protoboard labeled AM IN Amplitude Modulation and FM IN Frequency Modulation respectively 2 Launch LabVIEW Select Modulation vi from the Hands On NI ELVIS Library folder This program sends DC signals from NI ELVIS DAC output to the function generator to produce an amplitude or frequency modulated signal The modulated signal is converted to light pulses sent across the free space link and then detected on the phototransistor and converted back into an electrical signal You have just built an elementary free space optical communication link for analog signals 3 Close any SFPs and LabVIEW End of Exercise 8 4 National Instruments Corporation 8 9 Introduction to NI ELVIS Lab8 Free Space Optical Communication For Further Exploration NRZ Digital Modulation IR remote controllers use a special encoding scheme called NRZ A HI level is signaled by a
85. ve signal on the oscilloscope window For a steady signal trace trigger oscilloscope on Channel A Return to the DACO browse icon and navigate to the Hands On NI ELVIS Library folder and select the file Morse wdt This file provides the waveform for the letter S in Morse code Change the gain for DAC 0 to 2 5 9 8 ni com Lab 9 RF Wireless Communication 7 Click DAQO Play Stop button and observe this signal on the oscilloscope i NI ELVIS Arbitrary Waveform Generator Output Settings 10000 1 Sis Update Rate Trigger Source Play Stop All gt a 1a Morse wdt Waveform Name DACO Play Stop lt empty gt DACI Waveform Name 8 For the real transmission change the Update Rate box to 100000 00 S s End of Exercise 9 4 National Instruments Corporation 9 9 Introduction to NI ELVIS Lab9 RF Wireless Communication Exercise 9 5 A Demonstration of Marconi s RF Transmission Signal To complete the transmitter station complete the following steps 1 Install a 7408 quad 2 input AND digital IC to the protoboard Power 5 V is pin 14 and ground is pin 7 2 Connect the DACO output pin socket on NI ELVIS protoboard to pin 1 of the 7408 IC 3 Connect the FGEN output to pin 2 of the 7408 IC The transmitter is now pin 3 of the 7408 IC is connected to the paper clip transmitter antenna ON Antenna To DAC 0 FGEN 7 3 Sonat FUNC
86. which the output is always HI and a critical field B in below which the output is LO A graph of Hall Voltage versus range from sensor demonstrates hysteresis between the response of approaching the sensor and of leaving the sensor The difference between the two limits h B max B min is a measure of the noise immunity of the sensor For example if the sensor takes a particular field to switch from LO to HI it then requires a much smaller field Bmax A to switch to the opposite state HI to LO Because you are using a fixed magnet you can translate these critical fields from previous exercise into critical positions Close the Digital Multimeter End of Exercise 6 2 National Instruments Corporation 6 5 Introduction to NI ELVIS Lab6 Magnetic Field Sensor Exercise 6 3 Counting Pulses with a Magnetic Switch Sensor Complete the following steps to perform a pulse count measurement using the Hall Effect Switch ih Place the magnet far enough away from the sensor so it is in the LO state Move the south end of a magnet toward the sensor The magnetic field eventually exceeds B and the logic state toggles HI Then as the magnet is pulled away and the magnetic field becomes less than Bnin it switches back to the LO state The entire sequence LO HI LO generates a positive pulse Repeating this operation numerous times generates a train of positive pulses From the NI ELVIS Instrument Launcher select Oscilloscop
87. window The output signal is inverted with respect to the input This is expected for an inverting Op Amp circuit 12 Calculate the voltage gain the amplitude ratio channel A channel B Try a range of frequencies from 100 Hz to 10 kHz Observe any changes How do the measurements agree with the theoretical gain of R R 3 Note You can also use an analog trigger source from CH A or CH B This choice sets the Trigger Type to Analog SW allowing you to set the trigger slope and level 13 Close the FGEN and OSC windows End of Exercise 4 2 National Instruments Corporation 4 5 Introduction to NI ELVIS Lab4 Op Amp Filters Exercise 4 3 Measuring the Op Amp Frequency Characteristic The best way to study the AC characteristic response curve of the Op Amp is to measure its Bode plot The Bode plot is basically a plot of Gain dB and Phase degrees as a function of log frequency The transfer function for an Inverting Op Amp circuit is given by R Voui ca Vy where V is the Op Amp output and V is the Op Amp input the amplitude of FGEN in the circuit The Gain is the quantity R R The minus sign inverts the output signal with respect to the input signal On a Bode plot you expect a straight line with a magnitude of 20 x log Gain For a gain of 10 the Bode amplitude should be 20 dB Complete the following steps to measure the Bode plot of the Op Amp circuit 1 From the NI ELVIS Instrument Launcher select Bod
88. xercise 9 2 The Receiver Complete the following steps to build the receiver 1 Bend a second paper clip into a step shape with the long side about 2 5 in long the step height about 0 25 in and the step width about 0 5 in 2 Insert the short end of the paperclip into a pin socket The mid section supports the antenna on the protoboard and allows you to rotate the antenna about the short end The long side sits vertical and is parallel to the transmitter antenna as shown in Figure 9 1 3 Build a high gain amplifier using a 741 Op Amp or 753 FET Op Amp in the simple noninverting configuration Antenna Connect the 1 KQ resistor to the input pin 2 Connect a 100 kQ bias resistor to the input pin 3 Connect the other end of the resistors to AIGND aN Connect the other 100 KQ resistor for the feedback resistor R from pin 2 to 6 8 To power the circuit connect 15 V on pin 7 and 15 V on pin 4 Nominally the Op Amp has a gain of 101 You can use other resistor combinations for higher gains 9 Connect the receiver antenna to the input pin 3 10 Connect the Op Amp output pin 6 to the oscilloscope End of Exercise 9 2 Introduction to NI ELVIS 9 4 ni com Lab9 RF Wireless Communication Exercise 9 3 Testing the RF Transmitter and Receiver A sine wave signal is used to test the transmitter receiver pair Complete the following steps 1 Check the circuit you bui

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