Practicum 1: Multisim and myDAQ Tutorials
Introduction
The purpose of performing these tutorials is to acquaint you with the NI myDAQ
measurement module and the NI Multisim circuit simulation software. These tutorials will need
to be completed before performing Practicum 2 exercises involving the simulation and
measurement of the gain of an op amp circuit. While performing these tutorials, please provide
documentation and screen captures of your activity so as to summarize what was accomplished
in your electronic notebook.
Objectives
The objectives of this practicum are to
1. get acquainted with performing basic measurements with the myDAQ
2. learn how to setup the simulation of an op amp circuit using Multisim
3. learn how to use the myDAQ in tandem with Multisim
Rationale for the Use of the NI myDAQ Module in the Electronics Curriculum at VU
In the electronics curriculum for ECE 2550 and ECE 3550 the National Instruments’ myDAQ module
has been adopted to encourage a student to learn at his or her own pace wherever and whenever. The
pedagogy of these courses will emphasize developing an individual student’s knowledge on a certain
topic outside of class before structured, group-related activities are performed in a lab setting. Outside of
the classroom, a student will design, simulate, and measure the specifications of a circuit. As a result, a
student can more effectively contribute to peer-to-peer learning in the classroom, since each individual
will be well equipped to bring specific expertise to the group. Individual efforts combined with grouprelated activities will provide a new dynamic whereby each activity type feeds off the other and produces
motivated self-learners who are also strong collaborative members of a team. We believe that by doing
so, we would (1) provide opportunities for faculty to challenge the students to perform more complex
electronic circuit designs and (2) foster more productive and student-centered peer-to-peer interactions.
Ultimately, this increases the level of student engagement in classroom activities and the effectiveness of
the faculty’s teaching in the limited formal class time.
Getting Started with the NI myDAQ
National Instruments website provides all of the necessary background material to get started with the
myDAQ module (depicted below). Also, refer to the myDAQ_use_guide.pdf file at the course website.
To get started go to http://www.ni.com/white-paper/11213/en/#GetStarted . Install the software
drivers for the myDAQ and install the LabVIEW software. Also, install the Multisim circuit simulation
software. Once the installation is complete, familiarize yourself with the use of the myDAQ as a digital
multimeter (DMM), oscilloscope (Scope), function generator (FGEN), and DC power source (+/- 15V).
Basic Lab Measurement Exercises with the NI myDAQ and the NI ELVISmx Software Instruments Panel
1. Use the DMM features of the myDAQ through the control of the NI ELVISmx software instruments
panel (shown above) to measure DC voltage, current, and resistance. Use the red and black probes
and the banana jack connections on the bottom side of the myDAQ. To measure voltage or
resistance, connect the red probe to the HI port on the left and the black probe to the COM port in the
middle. To measure current, connect the red probe to the HI port on the right and the black probe to
the COM port in the middle. Refer to the Making Signal Connections with NI myDAQ section in the
myDAQ_user_guide.pdf for more information.
a. Obtain a 10 K resistor and measure its resistance with the DMM. Record its value.
b. Use the +15 V DC power source and connect the 10 K resistor between the +15 V and the
ground (AGND) connections (screw connectors on the right side of the myDAQ). Use the DMM
to measure the DC voltage across the resistor. Record its value. A virtual depiction of the simple
measurement circuit in Multisim is shown below. Note: all of the AGND connections are at the
same ground reference point, and the locations of the AGND connections in the Multisim
schematic depict the locations of the AGND connections in the original version of the myDAQ
module. Therefore, the locations of the AGND connections on your myDAQ module will be
different than the locations on the Multisim schematic.
c. Now measure the DC current in the simple power supply and resistor circuit. Remember to place
the red probe into the banana jack on the right HI to measure current. Place the DMM probes in
series between +15 V connector and the one end of the resistor. Measure the DC current through
the resistor. Record its value. Use the prior measured DC voltage and resistor values to verify
that the DC current measurement is correct. A virtual depiction of the simple measurement
circuit in Multisim is shown at the top of the next page.
2. Use the oscilloscope (Scope) and the function generator (FGEN) to capture a single AC signal.
a. Configure the function generator to generate a 2 Vpp sinewave signal with a 1 V DC offset at 1
KHz. The FGEN uses AO 0 on the screw terminal on an NI myDAQ for its output and AGND as
its ground reference.
b. Capture the sinewave signal using one of the two AI channels (AI 0 or AI 1) on the oscilloscope.
To use the AI 0 channel, use the 0+ and 0- connections. Provide a screen capture of the
measured signal. A virtual depiction of the simple measurement circuit in Multisim is shown
below along with the virtual scope screen shown at the top of the next page. (note the settings on
the FGEN and Scope control panels).
NI myDAQ Specifications
For the DMM, the maximum DC voltage is 60 VDC, the maximum AC voltage is 20 Vrms, the
maximum DC current is 1A, and the maximum AC current is 1Arms.
Input protection is achieved by an internal ceramic fuse, 1.25 A, 250 V, fast-acting, 5 x 20 mm,
F 1.25A H 250V (Littelfuse part number 02161.25). How to replace the internal fuse is described on page
14 of the myDAQ_user_guide.pdf.
Refer to the Specifications section in the myDAQ_user_guide.pdf for more information.
Getting Started with NI Multisim
Go to http://www.ni.com/multisim/technical-resources/ and go to the section on Getting
Started With Multisim. Click on the link Capture and simulate in less than 30 minutes and perform the
tutorial on the op amp circuit shown below.
Using myDAQ with NI Multisim Circuit Design Software
Go to http://www.ni.com/white-paper/11423/en/ and follow the tutorial on this webpage so
that you get additional experience with the myDAQ and the virtual myDAQ interface in
Multisim.