EET 438b SequentialControl and Data Acquisition

SIUC Department of Technology

Lab Activities

General Lab Materials and Policies

This course requires completing several laboratory activities that demonstate the theory and application of data acquisition and sequential control. These activities include both contructing hardware circuits and programming assignments using software.

Course lab activities utilizes circuit simulation software distributed by Cadence Design Systems  Cadance Design provides a student version of the OrCad PCB Designer Lite software is available from this site.  This software is a suite of software packages that provide Pspice circuit simulation and printed circuit board design capabilities.  The lite version is has limitations, but they will not imped use in this course.

This course using LabVIEW, by National Instruments to developed data collection and control applications.  The software simplifies the construction of user interfaces and the collection and scaling of measurements made with environmental transducers. Student versions of this software are available. Follow this link to access a supplier site. It can also be obtained from National Instruments directly.  The free version has limitations.  Make sure you have what you need for the course.

LabVIEW Tutorial Materials

LabVIEW software is a powerful graphical programming tool that allows developers to quickly create user interfaces, collect analog and digtial inputs, process the collected data, and display it in a meaningful way.. It combines with the Measurement and Automation Explorer Software to create data collection and tasks and channels. The links in this section lead to the National Instrument (NI) student tutorial website.   These videos will help you learn to use these software tools to perform to develop programs, collect transducer measurements and analyze the results

The first link leads to the National Instruments opening tutorial page.  You can select the topics to review from this location.  It includes learning LabVIEW and also includeds information on using the Measurement and Automation Explorer (MAX) software. This software provides the softwae drivers and hardware setup functions for all NI hardware.  Note that NI is always improving its software products and will be providing support for other microcontroller based devices.  Refer to this site for the latest developments and driver downloads.

The remaining tutorials from NI cover specific aspects of using the LabVIEW development system and programming in LabVIEW.  LabVIEW uses a graphical programming technique that can produce complex user interfaces quickly. Using LabVIEW conjunction with the MAX application, a developer can quickly product a data collection and control program that can reading analog information from transducers and sensors, make control decisions based on the acquired readings and output apropriate analog and digital control signals through a data acquistion device installed in a PC or connected to a host computer using a USB interface.

The tutorial links above give general information about program and using LABVIEW.  Each laboratory activity has a collection of specific video presentations that help you in performing the lab activities.

Laboratory Activities

Activity 1: Introduction to the LabVIEW Programming Enviornment

The lab activity introduces students to the graphical programming environment of LabVIEW.  In this programming system, a developer places interface elements on a simulated instrument panel.  Variables appear on a block diagram and are interconnected using lines.  This programming environment allows rapid development of applications and gives easy access to signal and measurement collected from analog and digital sensor acquired through a data acquisition card.  This activity asks students to develop simple programs that build skill in programming in LabVIEW.  Estimated Completition Time: 2 hours

The lab videos are a collection of tutorials from the makers of LabVIEW and others are created specifically for the lab assignments.

Activity 2: Programming Structures in LabVIEW

In this laboratory activity students will use programming structures to create more complex programs in LabVIEW. The activity show the use of the IF-THEN-ELSE, CASE, FOR loop and WHILE loops in the LabVIEW programming environment.  The activity presents the state-machine concept to handle sequential processes.  Student use a state-machine shell to produce a counter with a display  Estimated Completition Time: 3 hours

The Lab 2 videos link to the National Instrument website tutorial demonstrations.  Other videos give specific demonstrations for this lab activity.

Activity 3: Analog Data Acquisition Using LabVIEW and the Measurementand Automation Explorer (MAX)

This laboratory shows how to set up an analog measurement using the LabVIEW and Measurement and Automation Explore (MAX) softwares. The activity shows students how to set up and test an anlog channel using the MAX software. The activity demonstrates how LabVIEW programs gain access to defined channels.  This activity demonstrates the effects of sampling analog signal through an experiment that injects sine signals and observes if folding or aliasing occurs in the reconstucted samples.  Students design anti-aliasing filers and test their effectiveness comparing results to unfiltered results. Estimated Completition Time: 3-5 hours.

The lab videos show how to use the MAX and LabVIEW to collect analog information.

Activity 4: Analog Measurement and Digital Control Integration Using LabVIEW

This lab uses LabVIEW analog inputs and digital outputs to control a simple process. This activity shows how to configure analog inputs for both single-ended and grounded operation.  Students identify the voltage and current limitations of the data acquisition card's digital input/output port.   They will also design an analog scaling circuit to utilize the full range analog input.  Students write a LabVIEW program that senses light intensity values and change the light output of an LED array in discreet steps.  Estimated Completition Time: 3-4 hours.

The lab videos demonstrate how to create analog and digital channels using the MAX software.  Other videos show how to use Excel to plot non-linear sensor responses and use logarithems to produce a linear plot.  The Excel videos also show how to design a voltage divider using a photo resistor.

Activity 5: Dc Bridges in Measurement and Data Acquisition

This lab demonstrates the use of the dc or Wheatsone bridge.  This circuit is the basis for many commerical industrial transducers that measure, temperature, preasure, flow and force.  The activity shows how a dc bridge can operate in either the balanced or unbalanced mode and deliver accurate measures of small resistance changes in sensors.  Students constuct a bridge and use an analog output voltage controlled by a LabVIEW program to automatically balance a dc bridge. Student develop this program based on pseudo-code given in the lab documents. They then use derived formulas to convert the balancing voltage into a measured resistance value.  This project uses both analog inputs and outputs to monitor and control the system. Estimated Completition Time: 6-8 hours.

Activity 6: Introduction to Connected Components Workbench and Do-More Designer Software

This lab gives students expeience with Programmable Logic Controllers (PLCs).  These devices are a key building block of modern industrial automation.  This activity introduces the software used to develop and load programs into PLC's from the Connected Components line of controllers offered by Allen-Bradley.  Online students will use Do-More Designer by Automation Direct to develop their programs.  Students will learn to create and save simple ladder logic programs using a free software package provided.  They will also learn to download and monitor program operation using the debug/monitor functions of the software   Estimated Completition Time: 2-3 hours.

The lab videos introduce the PLC programming tools and demonstrate programming techniques.

Activity 7: PLC Function Programming Using Ladder Logic

This lab Introduces more advanced PLC programming structures.  These include on/off delay timers and up/down counters.  This activity sohws how to integrate these programming structures into PLC programs.  The lab activity shows how to develop PLC programs using logical state equations.  This method produces structured PLC programs that are easiser to implement and troubleshoot than those produced using other methods.  Students develop and debug a state-based PLC program that simulates an industrial process     Estimated Completition Time: 2-3 hours.

The lab videos demonstrate the use of timers and counters in a PLC program.

Activity 8: IEC 1131 PLC Programming Languages 1:  Introduction to Function Block Programming of a PLC

This lab gives students experience in programming a PLC using other standard forms of programming that are defined in the international standard IEC 1131.  These types of programming include the use of functional blocks similar to LabVIEW programming and structured text, which is similar to programming in C/C++.  Students use the Connected Components software to program PLCs using these other methods. Students will convert a electromechanical ladder control diagram into an equivalent function block program, load it into a PLC and test its operation. Estimated Completition Time: 2-3 hours.

The lab videos demonstrate the use of functional block and structured text programming.

Activity 9: Analog Input and Output USing PLCs

This lab gives students experience in programming a PLC using other standard forms of programming that are defined in the international standard IEC 1131.  C and test its operation. Estimated Completition Time: 2-3 hours.

The lab videos show the technical details of anlog expansion modules.  Other videos demonstrate how to use anlog inputs in a ladder logic program.