CheckSum TR-4/6 Instruction Manual · Model TR-4/6 Automated Test System INSTRUCTION MANUAL CheckSum, Inc. P.O. Box 3279 Arlington, WA 98223 (360) 435-5510 Web Site:

Model TR-4/6Automated Test SystemINSTRUCTION MANUAL

CheckSum, Inc.P.O. Box 3279

Arlington, WA 98223(360) 435-5510

Web Site: www.checksum.com

P/N 4400-010Revision 12/2003

Copyright © 1990-2003 - CheckSum, Inc. - all rights reservedLitho in U.S.A.

Specifications and operational characteristics of the System are subject to change. CheckSum, Inc.cannot take responsibility for any direct or consequential damages arising from use of this manual orthe related product.

IBM-PC, IBM-XT, and IBM-AT are trademarks of International Business Machines, Inc. MS-DOSis a trademark of Microsoft Inc. OrCad is a trademark of OrCad Systems Corp. CadStar is atrademark of Racal-Redac.

Table of Contents

Chapter 1 Introduction Getting Started 1-1System Overview 1-2

Chapter 2 Operational Overview Installation 2-1Connection to the UUT 2-4Creating a Spec File 2-5Testing an Assembly 2-7

Chapter 3 Specifications Model TR-4 MDA System 3-1Model TR-6 Functional Test System 3-6Model TR4/6 CheckSum Test System Software 3-13Model RM-1 Relay Module 3-15Model GPIB IEEE-488 Interface 3-15System Configuration 3-18

Chapter 4 Theory of OperationModel TR-4

Overview 4-1Current Mode 4-2Voltage Mode 4-6

Model TR-6Overview 4-11

Measurement Guidelines 4-16

Chapter 5 Installation InstructionsOverview 5-1Model TR-4 System Module Installation 5-3Model MPX-3-200/TR-4-1D MPX Module Installation 5-6Model TR-6 System Module Installation 5-9Model TR-6-1 Relay MPX Module Installation 5-9Accessory Module Installation 5-10Completing the Hardware Installation 5-13CheckSum Test System Software Installation 5-14Connection to the UUT 5-19

CheckSum Model TR-4/6 Manual Page i

Chapter 6 Testing an AssemblyOverview 6-1Selecting the Proper Spec Data 6-4Performing the Test 6-8Concluding the Test 6-12

Chapter 7 Learning an AssemblyOverview 7-1Assembly Learn Menu 7-3Assigning Connection Information 7-6Enter/Edit Spec Data 7-8Autolearn/Autoguard Use and Configuration 7-13QuickGuard Configuration 7-16Measurement Analysis 7-18Nominal Fit 7-22Dynamic Point Analysis 7-25Edit/Enter Continuity Test Data 7-28Edit/Enter IC Test Data 7-33DMM Interactive Control 7-36UCT Interactive Control 7-38Assigning Operator Messages 7-40Global Spec File Operations 7-42Edit/Enter Fixture-Check Data 7-45Special Features 7-46Assign Other Measurement Characteristics 7-48Auto Programming 7-50Translating Spec Data To and From an ASCII File 7-54Assign Measurement Characteristics 7-56Assign Operator Setup Screen 7-58Printing Specification or Wire List Data 7-60Testing Multi-PCB Panels 7-61Multi-PCB Panel Configuration 7-65Testing Digital Logic 7-69

Chapter 8 CAD Data ConversionOverview 8-1Generating the Spec File 8-2CAD Conversion Selections Menu 8-4Enter/Edit Reference Designator Template 8-8Selective Spec Data Generation 8-9Notes on P-Cad Data Conversion 8-12Notes on Mentor Data Conversion 8-14

CheckSum Model TR-4/6 Manual Page ii

Chapter 8 CAD Data Conversion, continuedNotes on OrCAD Data Conversion 8-16Notes on HP-BCF Data Conversion 8-18Notes on Cadence Data Conversion 8-19Notes on Racal-Redac Data Conversion 8-20Notes on ViewLogic Data Conversion 8-22Notes on Tango Data Conversion 8-24Notes on ComputerVision Data Conversion 8-26Notes on Pads2000 Data Conversion 8-29Notes on Schema Data Conversion 8-31Notes on Scicards Data Conversion 8-32Notes on Fabmaster Data Conversion 8-33

Chapter 9 Statistical AnalysisStatistical Process Control Reporting 9-1

Chapter 10 Configuring the SystemOverview 10-01Model TR-4 Module Configuration 10-03Model TR-6 Module Configuration 10-06Other Hardware Configuration 10-09Assign Passwords and Password Privileges 10-12Configure Test Environment 10-14Configure SPC Logging & Automatic Reporting 10-16Configure Test Reports 10-19

Chapter 11 Test Type DescriptionsAnalog Measurement Test Types 11-04Analog Stimulus Test Types 11-28Digital Test Types 11-33Transfer of Control Test Types 11-41Message Test Types 11-51User-Defined Tests 11-57Memory Manipulation Test Types 11-59General Purpose Interface Bus I/O 11-67Miscellaneous Tests 11-77Wiring Diagrams Appendix ASample Reports Appendix BCommand Line Parameters Appendix CIn Case of Problems Appendix DError Messages Appendix EGlossary Appendix FExample Spec File Segments Appendix GIndex

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CheckSum Model TR-4/6 Manual Page iv

Figures & Illustrations

Figure Title Page Number

Figure 1-1 System Block Diagram 1-3Figure 2-1 Module Orientation 2-2Figure 4-1 Current Mode Block Diagram 4-2Figure 4-2 External Sensing Diagram 4-3Figure 4-3 Circuit with Parallel Components 4-5Figure 4-4 Circuit with Current Guarding 4-5Figure 4-5 Voltage Mode Block Diagram 4-6Figure 4-6 Series LR Model 4-7Figure 4-7 Parallel RC Model 4-7Figure 4-8 Series RC Model 4-8Figure 4-9 Offset 4-8Figure 4-10 Circuit with Voltage Guarding 4-10Figure 4-11 Choosing Voltage Mode Guards 4-18Figure 4-12 Choosing Current Mode Guards 4-18Figure 5-1 Module Configuration 5-2Figure 5-2 CheckSum Module Base Address Jumpering 5-3Figure 5-3 Aux I/O Pinout 5-5Figure 5-4 Model MPX-3/TR-4-1D MPX Installation 5-8Figure 5-5 System Menu 5-16Figure 5-6 Configure/Install System Menu 5-17Figure 5-7 Model MPX-3/TR-4-1D Test Point Pin-Out 5-19Figure 5-8 Model TR-6-1 Test Point Pin-Out 5-20Figure 5-9 Model TR-6 System Module Pin-Out 5-21Figure 6-1 System Menu 6-2Figure 6-2 File Selection Menu 6-4Figure 6-3 File Selection List 6-6Figure 6-4 Spec File Execution Parameters 6-7Figure 6-5 Testing Display 6-8Figure 6-6 Halt on Failure for Continuity Screen 6-11Figure 6-7 Test Completed Menu 6-12Figure 7-1 Assembly Learn Menu 7-3Figure 7-2 Assign Connection Information Screen 7-6Figure 7-3 Enter/Edit Spec Data Screen 7-8Figure 7-4 Autolearn Configuration 7-13Figure 7-5 Select QuickGuard Points Screen 7-16

CheckSum Model TR-4/6 Manual Page v


Figure 7-6 Measurement Analysis Display 7-19Figure 7-7 Nominal Fit Display 7-22Figure 7-8 Dynamic Point Analysis Screen 7-25Figure 7-9 Edit/Enter Continuity Test Data Screen 7-30Figure 7-10 Edit/Enter IC Test Data 7-34Figure 7-11 DMM Interactive Control Menu 7-36Figure 7-12 UCT Interactive Control Menu 7-38Figure 7-13 Assign Operator Messages Screen 7-40Figure 7-14 Global Spec File Operations Menu 7-42Figure 7-15 Edit/Enter Fixture-Check Data Screen 7-45Figure 7-16 Special Features Menu 7-46Figure 7-17 Assign Other Measurement Characteristics Menu 7-48Figure 7-18 Autoprogram UUT Menu 7-51Figure 7-19 Autoprogram UUT Parameters 7-52Figure 7-20 Resistance Measurement Characteristics Screen 7-56Figure 7-21 Operator Setup Entry Screen 7-58Figure 7-22 Spec File Report Device Selection List 7-60Figure 7-23 Testing Display with Multi-PCB Panels 7-61Figure 7-24 Skip PCBs in Panel 7-62Figure 7-25 Test Completed Display with Multi-PCB Panels 7-63Figure 7-26 Multi-PCB Panel Configuration Menu 7-65Figure 7-27 Panel Configuration Screen 7-67Figure 7-28 PCB Wiring Assignments Screen 7-68Figure 7-29 Example Circuit for Logic Test 7-71Figure 7-30A Logic Test File for Test Steps of Example Spec File 7-72Figure 7-30B Example Logic Spec File in ASCII Format 7-72Figure 7-31 G-80-ODM Input/Output Pin Mapping When

Connected to a Model G-807-73

Figure 8-1 CAD Conversion Selections Menu 8-4Figure 8-2 Example Fixture Wiring List 8-5Figure 8-3 Example Exception Report 8-7Figure 8-4 Enter/Edit Reference Designator Template Screen 8-8Figure 8-5 Selective Spec Data Generation Menu 8-10Figure 8-6 P-Cad Net List Format 8-12Figure 8-7 P-Cad Materials List Format 8-13Figure 8-8 Mentor Net List Format 8-14Figure 8-9 Mentor Component List Format 8-15Figure 8-10 OrCAD Cross-Reference File Format 8-16Figure 8-11 HP-BCF File Format 8-18

CheckSum Model TR-4/6 Manual Page vi


Figure 8-12 Cadence Net List Format 8-19Figure 8-13 Racal-Redac Net List Format 8-20Figure 8-14 Racal-Redac Materials List Format 8-21Figure 8-15 ViewLogic Net List Format 8-23Figure 8-16 Tango Net List Format 8-25Figure 8-17 ComputerVision Net List Format 8-27Figure 8-18 Modified Mentor Component List Format 8-28Figure 8-19 Pads2000 Net List Format 8-29Figure 8-20 Pads2000 Component List Format 8-30Figure 8-21 Scicards CAD Data Format 8-32Figure 8-22 Fabmaster Net List Format 8-33Figure 8-23 Fabmaster Materials List Format 8-34Figure 8-24 Fabmaster Nails File Format 8-35Figure 9-1 Statistical Analysis Menu 9-1Figure 10-1 Configure/Install System Menu 10-1Figure 10-2 Model TR-4 Module Configuration Screen 10-4Figure 10-3 Model TR-6 Module Configuration Screen 10-7Figure 10-4 Model TR-6 Calibration Screen 10-9Figure 10-5 Other Hardware Configuration Screen 10-10Figure 10-6 Configure Accessories & Fixture Screen 10-11Figure 10-7 Password Access Menu 10-13Figure 10-8 Configure Test Environment Menu 10-14Figure 10-9 Configure SPC Logging & Automatic Reporting Menu 10-16Figure 10-10 Configure Test Report Menu 10-19Figure 10-11 Configure Test Report Header Items Menu 10-21Figure 10-12 80-Column Test Report Fields Menu 10-22

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CheckSum Model TR-4/6 Manual Page viii

Limited Warranty

CheckSum, Inc. products, exclusive of fixturing products, are covered by a one-yearlimited parts and labor warranty for defects in materials and workmanship from time oforiginal product shipment. Fixturing products (Model TR-3/TR-5/TR-7 series and ModelGS-850) include a 90-day limited warranty. This warranty extends only to the original pur-chaser and excludes products or parts that have been subject to misuse, neglect, accident,or abnormal conditions of operations.

CheckSum, Inc. reserves the right to replace the product in lieu of repair. If the failurehas been caused, as determined by CheckSum, by misuse, neglect, accident, or abnormalconditions of operation, repairs will be invoiced at a nominal cost. In such case, an es-timate will be submitted before the work is started, if requested.

THE FOREGOING WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESS OR IM-PLIED, INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTY OF MERCHAN-TABILITY, FITNESS, OR ADEQUACY FOR ANY PARTICULAR PURPOSE OR USE. CHECKSUM,INC. SHALL NOT BE LIABLE FOR ANY SPECIAL, INCIDENTAL, OR CONSEQUENTIALDAMAGES, WHETHER IN CONTRACT, TORT, OR OTHERWISE.

In the event of a failure of a product during the warranty period:

1. Contact CheckSum for a returned material authorization number (RMA).

2. Pack the product in its original packing material or suitable equivalent and returnit postage-paid to CheckSum, Inc.. Mark the package clearly with the RMA num-ber.

3. CheckSum will repair the product and return it postage-paid. Repairs are typical-ly completed within two working days of receipt.

In the event that expedited repair is necessary, call CheckSum for information. In manycases a replacement module can be provided immediately.

CheckSum Model TR-4/6 Manual Page ix

CheckSum Model TR-4/6 Manual Page x

Introduction

Getting Started

This instruction manual is for use with the CheckSum Model TR-4 Manufacturing DefectsAnalyzer (MDA) System, the CheckSum Model TR-6 Functional Test System, or thecombined Model TR-4/6 Test System. Since these Systems are based on a commonhardware and software architecture, most descriptions are shared. Programming and useis very similar between the Systems, with the most significant exception being that testcommands (Chapter 11) for controlling measurements and stimuli are specific to each ofthe Systems.

In order to best serve your long-term needs, the Model TR-4 Manufacturing DefectsAnalyzer System and Model TR-6 Functional Test System contain a number of featuresand capabilities. Because of this, it may take you some time before you want (or need) touse all the features of the System.

To help you get your System up and testing as quickly as possible, you might want toexpedite your initial reading of the manual. The manual has been organized to supportyou in doing so.

First, read this Introduction. You also might want to look over Appendix F, the Glossary,to become accustomed to the terminology used with the System. Then read through thenext section of this manual, the Operational Overview. By this time, you will have a goodgeneral knowledge of what the System can do and how to navigate your way around.

Finally, using the remainder of the manual as reference material, you can install yourhardware and software, and begin experimenting with the System as you become familiarwith its use.

Check the software disk enclosed with your System. If it has a READ.ME file, print theREAD.ME file for any last-minute information about System updates.

If you run into problems or have questions, don’t hesitate to call CheckSum for assistance.We are here to help you.

CheckSum Model TR-4/6 Manual Page 1-1

System Overview

The CheckSum Model TR-4 Manufacturing Defects Analyzer System allows an IBM PC(or compatible) to efficiently test assemblies (such as cables, components and bare orassembled circuits) to find manufacturing defects such as opens, shorts, and incorrect ormisoriented components. The System makes high-speed measurements for opens andshorts, resistances, capacitances, inductances, voltages and semiconductor junctions. Foreach test it makes a measurement of a pair of test points in the unit-under-test (UUT)and compares the outcome against individual, user-specified upper and lower test limits.

The CheckSum Model TR-4 MDA Core System contains the System electronics formaking measurements, CheckSoft Software, and this Instruction Manual. Test points areadded in 200-test point increments (with Model TR-4-1 MPX Modules) to a maximum of1600 test points.

The Model TR-6 Functional Test System provides the capability to power- up the UUTand to apply stimulus and make measurements while powered-up. This can be used toconfirm that the UUT’s circuitry is functioning properly.

The Model TR-6 Core System is comprised of a single, full-sized module that contains aDMM, Counter/Timer, Function Generator, Digital I/O, sixteen relay test points, fusedpower outputs, and four undedicated relays.

The Model TR-6-1 Relay MPX Module expands the relay switching of the Model TR-6 in50-test-point increments. Relay switch points are used when measuring low resistances orwhen the test points are subject to voltages greater than +/-12 volts (with respect to thePC chassis).

The Model TR-6-2 Fixture Interface allows you to provide special functions near theUUT to help facilitate functional testing. These functions include switching high power tothe UUT, buffering and conditioning of signals (e.g. frequency-dividing and redriving anoscillator signal from the UUT), and switching or disconnecting signals near the UUT toreduce capacitive loading or to support special signal cabling requirements.

The Model-GPIB allows a Model TR-4 or TR-6 to use external IEEE-488instrumentation to supplement testing operations. The software is designed to supportthe specific GPIB module supplied by CheckSum.

The Model TR-4 and TR-6 Base Systems each provide eight digital I/O bits that can beused for control of external solid-state relays (such as those produced by Opto-22) forinput or output, or for LS-TTL or CMOS-compatible logic for purposes of functionaltesting of the UUT. The Model TR-6 digital I/O can also directly control relays (it isopen-collector). The TR-6 also supports output of DC voltages directly to severalsimultaneous test points (up to 16) through the Model TR-4 test points. These can beused to supply digital signals.


If additional digital I/O points are needed, 96 more digital bits can be added with anoptional CheckSum Model G-80 Digital I/O Module.

The Model TR-6 or TR-4 can either be used on a standalone basis, or can be used incombination. When this is the case, the test points and other capabilities can be sharedby the two Systems. The Model TR-6 can also be used with Model TR-4-1 (or TR-4-1D)MPX modules, even if a Model TR-4 Base System is not used.

Figure 1-1 - System Block Diagram

You can provide your own fixturing that is compatible with the 50-pin ribbon cablesprovided with the System or purchase a fixture from CheckSum:

1. The CheckSum Model TR-3 Vacuum Fixture System provides bed-of-nailscapability for testing bare or assembled PCBs. It uses a GenRad 2270-stylereceiver interface for interchangeable test heads.

2. The CheckSum Model TR-5 Mechanical Fixture Systems provide bed-of-nailscapability for testing small bare or assembled PCBs. These mechanical fixturesare used for PCBs with up to 150 test points to provide a low-cost, compact fixturewithout the requirement for a vacuum source or fixture receiver.


3. The CheckSum Model GS-850 Fixture System provides an interface to edge con-nectors or sockets that mate to the UUT. Each Model GS-850 Fixture can accom-modate up to 240 test points via two removable adapter boards. Adapter boardsare available prewired for common connector types or in breadboard format thatyou can customize for your UUT.

Other System options include controllers (PCs) of various speeds and a foot switch thatcan provide operator input to the System.

The System software provides the ability to program (‘learn’) the test sequence for aUUT. The System can self-learn the opens and connections for a UUT, then allows youto easily add the component tests. The initial test data can also be entered via compatibleCAD data if available. Once the UUT is learned, you may save the information (calledthe specification file, or spec file for short) on your System disk. It can be recalled laterto test UUTs. Once a UUT is tested you may generate various types of test reports orgather statistics to help control the manufacturing process.


Operational Overview

This section guides you through typical complete sequences for each major use of theSystem. These sequences include:

• Installation

• Fixturing

• Creation of a Spec File for a UUT

• Testing a UUT

Read through this section to get an overview of each activity. Complete detail is notgiven in this section, so you will probably want to refer to the individual sections of themanual that describe each action in detail as you perform the task.

Installation

The Model TR-4/6 controller (PC) minimally requires an 80386 processor with afull-sized slot available for each module system or MPX module. The modules can beinstalled in either 8-bit or 16-bit slots.

Figure 2-1 shows a suggested ordering of the modules, cable installation overview, anddefault base addresses.

For a Model TR-4 MDA system, the Model TR-4 System Module is first installed in yourPC. As delivered from CheckSum, it is jumpered to base address 768 (300 hex).

For a Model TR-6 Functional Test System, the Model TR-6 System Module is firstinstalled in your PC. As delivered from CheckSum, it is jumpered to base address 816(330 hex).

For a combined TR-4/6 System, install both the TR-4 and TR-6 modules in the ordershown in Figure 2-1. Install a short 16-pin bus cable from the TR-4 connector (JP-1) tothe TR-6 connector (JP-2).

For every additional 50 test points of relay switching that are to be used (for Systems witha Model TR-6), install a Model TR-6-1 Module. The default base addresses for these


modules are 832 (hex 340), 848 (hex 350), and so on. Install a two-wire bus connectingthe TR-6 (JP-5) to each of the TR-6-1 modules (JP-2).

For every 200 test points of solid-state switching that are to be used, an MPX(MPX-3-200 or TR-4-1D) Module is installed. As shipped, the first MPX-3-200 moduleis set to a base address of 672 decimal (2A0 hex, JP2 jumpers on positions 9, 7, and 5) anda Board Select setting of 1 decimal (1 hex, JP3 jumper on position 0). The TR-4-1DModules are jumpered to 776 (hex 308), 780 (hex 30C), and so on. Connect the 16-pinbus cable to JP-1 on each MPX module. For a TR-4 System, connect the end of the cableto JP-1 on the TR-4 system module. For a System with a Model TR-6, connect the end ofthe 16-pin cable to JP-3 on the TR-6 system module.

Note

Plug the modules into your PC, taking normal safety and electrostatic dis-charge (ESD) precautions: turn off power and ground your body to the PCprior to installation. Ensure that the 50-pin test point ribbon cables are in-stalled with each MPX Module during the installation. You might find iteasier to install the MPX modules first to allow easier routing of the 50-pincables.

Figure 2-1 - Module Orientation

Once the hardware is installed, install the CheckSoft Software in your PC. If you have ahard disk, put the CheckSoft disk into A:, assign A:, then run the INSTALL program(type INSTALL[Enter]). If you don’t have a hard disk, back up the CheckSoft disk (using

Viewed from top of controller

Module Installation

Test Points

1601-1616

---

1651-1700

Back

of

PC

(2-pin bus)

JP-5

JP-2

TR-4 System Module (Base 768)

TR-6 System Module (Base 816)

TR-6-1 Relay MPX Modules (Base 832, 848,...)

(16-pin bus)

JP-1JP-2

JP-3

JP-1TR-4-1 MPX Modules (Base 776, 780,...)

"

"

JP-21701-1750,...

1-200

201-400,...

---Other Modules (Model GPIB, RM-1)

JP-1


DISKCOPY or similar tools), then put the CheckSoft disk into A: and assign it (A:followed by [Enter]).

Start the CheckSoft Software by typing MDA[Enter]. At this point, you will see theSystem menu which is the hub of all System operations.

When first installing the System, it is necessary to run a self-test. This ensures that thehardware is installed properly. It also performs some special accuracy and speedenhancement functions that allow your System to operate properly. Self-test is executedby selecting ‘Configure/Install System’ from the System menu ([F4]), then ‘[F1] ModelTR-4 module configuration’, and/or ‘[F2] Model TR-6 module configuration’ as necessary.Once in the applicable module configuration screen, individually select each moduleinstalled in the System and press ‘[F1] Self-test module’.

Once self-test has started, press the keys as prompted to sequence through the self-test.Once the System Modules are completed, test each MPX Module that is installed byselecting each at a time. As part of the MPX (MPX-3 and TR-4-1D) self-test process, theSystem will ask you to install a shorting fixture to each 50-pin ribbon cable in sequence.The shorting fixture is included with the TR-4 System and can be connected onto eachcable, then removed with its ejection levers. As the MPXs are shorted, the Systemmeasures the zero-offset values associated with each test point. This is necessary toensure full accuracy is achieved.

Once self-test is completed, select ‘Save configuration data on disk’ ([F8]) to save thesetup information determined during the self-test for use next time the System is used.

‘Saving configuration data on disk’ saves the current value for most selections of theConfigure/Install System menu and its submenus. Saved values include most of the Systemoperating characteristics such as self-test determined data, report configuration, activeports, and measurement characteristics.

The Model TR-4 and TR-6 can be tested against external standards if desired. This canbe used to meet standards of traceability for the Systems.

The optional Model CM-3 Calibration Module provides software and hardware to testModel TR-4 Test System operation against values external to the System. You canconfirm/characterize the values of the components on the Calibration Module in yourcalibration facility if desired.

The Model TR-6 can be calibrated to external standards using a DMM and MultifunctionCalibrator. This process determines calibration constants for the system to obtain fullaccuracy. This process is described in Chapter 10 of this Manual.


Connecting to the UUT

The System’s measurements are made via test points available at the end of the 50-pinribbon cables that come from the back of the Model TR-6 System Module,MPX-3-200/TR-4-1D Modules, and TR-6-1 MPX Modules. Each pin is called a port ortest point. Each test point is completely universal in nature and can be connected to anyUUT test point, although selection of test points between relay test points (TR-6) andsolid state MPX points (TR-4) should be separated based on the nature of the UUT.Also, if you are using Model TR-4-1D modules, the first 16 points on each module arespecial in that they can be switched to digital points. The MPX-3-200 does not supportdigital I/O.

For MDA testing (or TR-6 testing through the Model TR-4-1D test points), all MPX(MPX-3-200/TR-4-1D) test points (points 1-1600) are electrically equivalent and can bewired randomly. If you are not concerned with detailed pin and connection names foroperator interaction and reports, it is not even necessary to know how the UUT isconnected to the System for doing MDA opens and shorts testing. The System canself-learn a UUT without concern for user-assigned pin and connection names.

For functional testing, you should use Model TR-6 (and TR-6-1) relay test points fornodes on the UUT that exceed +/- 12V with respect to the computer chassis, or pointsthat you want to use for low-resistance TR-6 DMM measurements. You should useMPX-3/TR-4-1D test points whenever possible since they have the widest spectrum ofcapabilities (e.g., continuity testing, guarded measurements, signal sourcing).

The pin-out of the MPX-3-200/TR-4-1D MPX Module is shown in Appendix A. Notethat test points 1, 51, 101, and 151 are at the bottom of JP9, JP8, JP7, and JP6respectively. Test points 1 - 200 are on the first MPX Module shown in the ‘Set I/Omodule configuration’ display of the Configure/Install System menu. Test points 201 - 400are contained on the second MPX Module shown in the display, and so on. If you are notsure about the pin out, use the ‘Probe a pin’ feature available from the ‘[F3] AssignConnection Information’ selection of the Assembly Learn menu. If you enable thisfeature, then touch a grounded probe to the port in question, the System will display thetest point number.

The Model TR-6 System Module signals are available at the back panel of the module.The TR-6 system module can be differentiated from the Model TR-6-1 MPX modulesbecause the back panel connector is a special color (typically blue). The pin-out of thismodule is shown in Appendix A of this manual. The 16 test points available from thismodule are numbers 1601-1616.

Note

The Model TR-6 System Module back panel connector contains powersupply voltages that could harm your fixture or UUT. Ensure that you donot route this cable to the wrong spot on your fixture.


The Model TR-6 Relay MPX modules have 50 test points available at each back panel.These test points are numbered as 1651-1700, 1701-1750, and so on.

Creating a Spec File

The specification file (spec file) tells the System how to test an assembly (also called theunit-under-test or UUT). The spec file is typically generated once, saved on the disk,then used each time one or more of the same UUTs are tested.

The spec file consists of a number of test steps, most of which can generate test results.Typical test types include CONT for continuity, RES for resistance tests, DMM forvoltage and resistance measurements, UCT for frequency and time measurements, CAPfor capacitance tests, INDUC for inductance tests and DIODE for semiconductor junctiontests. For most of these test types, the test step contains upper and lower test limits, thetwo test point numbers and names, the measurement range, and a test title describing thecomponent being tested. In addition, the spec file contains pin names (optionallyassigned), the measurement characteristics (e.g., samples averaged for each reading),active ports, the assembly name (optional) and operator comments (optional instructionsto the operator).

Generating a spec file can be performed in several ways. All are available from the‘Learn an Assembly’ ([F2]) selection of the System menu. You may use the System inrandom sequences of configuration, learning, testing, and other operations. When you aresatisfied that your PC’s memory contains the proper spec data, save it to disk.

Following is a typical programming sequence:

The ‘Assign Connection Information’ ([F3]) selection of the Assembly Learn menuallows you to enter names specific to your UUT into the System. When you do this,the System displays and reports will contain the names that you enter. Each pinname can be up to eight characters. The System can automatically assign sequentialpin names as you probe the fixture, making this process quick and easy. The ‘AssignConnection Information’ selection also allows you to specify which test points areactive and inactive (ignored) when learning CONTinuity for an assembly.

Once you have assigned pin names, you can use the ‘[F8] Output Wire List Report’selection of the Learn menu selection to generate a wiring list for the UUT.

Use the Enter/Edit Spec Data screen ([F2] from the Assembly Learn menu) to enter atest type of CONT (continuity). Then select [F5] to get the Enter/Edit Continuity TestData screen. Finally, use the [F6] selection to automatically learn the UUT’s opensand shorts.

Once the connections are learned, [ESC] back to the Enter/Edit Spec Data menu.For each component in the UUT, press [INS]sert, enter the two test point numbers(‘from’ and ‘to’ port numbers) or pin names, the test type (e.g., RES, CAP, INDUC


or DIODE), and the component name in the test title (e.g., R101). Then press [F5]for the System to measure the points, assign the range and test tolerances.

Note that at times the measurement values will be different from the nominal valuesof the components that you are measuring. This is a normal case caused byinterference from associated circuitry on the UUT. Even though the test limits maynot represent the nominal value of the component, the System will still efficiently findmost manufacturing faults because differences from the learned value are detected.

These measurement differences can be minimized by careful selection of ranges andpolarities used in the measurements, guarding, and the use of zero/scale values. Theuses of these advanced features are described in detail in the Learning an Assemblychapter. The Theory of Operation chapter describes how the System makesmeasurements to allow you to make the best measurements if you run across problemcomponents.

Once the MDA tests are completed, you can use the Model TR-6 to power up theUUT, apply stimulus and make measurements of various signal points on the UUT.

The Assign operator set-up screen, accessed from [F4], can be used to create a screenof text that the operator sees prior to beginning a test for each UUT. This text canbe used for precautions, connection information, or other things that you would liketo convey to the operator.

Once you have entered the spec data, you will want to run a batch of UUTs throughthe System to verify that the tolerances are appropriate to meet the UUT-to-UUTand measurement variances. As you do this, if you encounter a failure that is notcaused by a fault in the UUT, press the [F5] key while observing the failure. TheSystem will adjust the test tolerances to accommodate the UUT that you are testing.Note that the [F5] key is hidden in the Testing display so that operators won’t have atendency to use it during production testing (it is also password-protected). You canuse data logging in conjunction with the X-Bar/Sigma Control Report to helpdetermine appropriate tolerances by analyzing the readings from the first few batchesof UUTs tested.

‘Output spec data report’ ([F7]) lists information about the spec data presently inmemory. It may be sent to the CRT, a disk file or a printer.

‘Output wire list report’ ([F8]) outputs a report that shows the correlation betweentester port numbers and pin names that you have assigned. The report is sorted byboth port numbers and pin names.

‘Save spec data to disk’ ([F9]) is used to save the spec data for future use. Thisinformation is on the System disk. Consequently, when the spec file is loaded in thefuture this information will be restored to match the conditions when the spec filewas saved.


Testing an Assembly

Once you have generated a spec file for a UUT, the UUT may be tested. To test a UUT,select ‘Test an Assembly’ ([F1]) from the System menu. You are then presented with theSelect Spec Data File menu. Either enter [F2] and type in the spec file name or use the‘Select Spec Data File From List’ ([F3]) to choose the proper spec file. Once the properspec file is loaded into memory, select ‘Start Test With Present File’ ([F1]) to actuallystart the test. You may elect to single step or halt on failure from this display if you wish.

If the test fails any points (and you have selected halt on fail), you are presented with adisplay describing the failure. You may either continue, abort or retry the test.

Once the test is completed or aborted, you see the Test Completed menu. This menuallows you to either continue on to the next assembly in this run or to retest the presentassembly.

At any point you may also generate a report. The test report ([F3]) contains the actualmeasurements for the UUT. A failure-only report ([F4]) lists only the test values thatfailed. The batch report ([F5]) gives a summary of all of the UUTs tested in this run.


Specifications

Model TR-4 MDA System

Resistance Measurement Characteristics

Voltage Technique

• Frequency: DC, 100 Hz or 1 KHz sine wave

• Output Voltage into Open: 200 mV or 2 V

• Output Impedance: ≈ 600 Ω

• Max Current Through Unknown:2V range: ≈ 3.3 mA200 mV range: ≈ 33 mA

• Typical Accuracy:0 - 10 KΩ: 2% of reading + 0.5 Ω10 KΩ - 1 MΩ: 3% of reading1 MΩ - 19 MΩ: 10% of reading

• Approximate Measurement Speed:DC: 12 mSec1 KHz: 18 mSec100 Hz: 130 mSec

Current Mode

Full Range Volts(Full Range)

Current Typical Accuracy

190 Ω 0.2 V 1.0 mA ± 0.5 Ω1.9 KΩ 2 V 1.0 mA ± 9 Ω19 KΩ 2 V 0.1 mA ± 190 Ω

190 KΩ 2 V 10.0 µA ± 4.5 KΩ1.9 MΩ 2 V 1.0 µA ± 95 KΩ19 MΩ 2 V 0.1 µA ± 1.9 MΩ

Full-range values shown applicable for externally sensed measurements. Reducevalue by ≈ 20 Ω when using internally sensed measurements.

Reduced accuracy with other 200 mV ranges.


Test speed is ≈ 4 mSec per test point switching, measurement, and evaluation time whenmeasuring a value less than 190 Ω. Worst-case time of ≈ 50 mSec when autoranging from0 Ω to a measurement on the 19 MΩ range.

System uses internal Kelvin measurements for compensation of switching resistance withan offset stored for lead and contact resistance from that point. Readings can beexternally sensed at device being measured if desired.

Capacitance Measurement Characteristics

Voltage Mode

• Frequency: 100 Hz or 1 KHz sine wave



• Max Current Through Unknown:2V range: ≈ 3.3 mA200 mV range: ≈ 0.33 mA

• Usable Range:100 Hz: 10 pF to 20,000 µF1 KHz: 0 pF to 2,000 µF

• Typical Accuracy: 5% with zero-offset compensation

• Usable Resolution: ≈ 0.5% (minimally 5 pF)

• Approximate Measurement Speed:1 KHz: 18 mSec100 Hz: 130 mSec

Current Mode

• Six-decade ranges from .05 µ to 5,000 µF, providing a usable range of 500 pF to20,000 µF.

• Typical Accuracy: ± 5% (Reading accuracy may degrade if capacitorbeing tested has significant leakage.)

• Resolution: 1% of range

• Technique: Inject DC current, measure rise characteristics of voltage across unknown.

• Stimulus: 0.1 µA to 1 mA in decade ranges. 2 V or 200 mV full-range voltage acrossunknown.


Inductance Measurement Characteristics

• Frequency: 100 Hz or 1 KHz sine wave



• Max Current Through Unknown:2V range: ≈ 3.3 mA200 mV range: ≈ 0.33 mA

• Usable Range: 6 µH - 1000 H

• Typical Accuracy: 5% with zero-offset compensation

• Usable Resolution: ≈ 0.5% (minimally 0.5 µH)

• Approximate Measurement Speed:1 KHz: 18 mSec100 Hz: 130 mSec

Voltage Measurement Characteristics

• Range: 0 to 9.9 V

• Typical Accuracy: ± 200 mV

• Speed: ≈ 1-2 mSec/measurement

Continuity Measurement Characteristics

Connection and open thresholds are separately programmable from 2 Ω to 50 Ω. Eachtest point pair can be specified as open, connection or not tested.

Maximum open/short test time for 200 test points is 6.8 sec.. Each measurement takesapproximately 330 µSec. The worst-case total time to test a block of n test points can becalculated as:

T = 330 µS × n ( n − 1 )2

The System uses optimizations to increase speed of continuity testing. In most cases testspeed is much faster than the times listed above. For example, a CONT test for a typical200-test point assembly executes in less than a second.


Semiconductor Measurement Characteristics

• Technique: Source constant-current in decade values (1 mAthrough 0.1 µA), measure voltage.

• Typical Accuracy:0-2 V: ± 2 mV2-9.9 V: ± 20 mV

• Speed: ≈ 1-2 mSec/measurement

Digital I/O Capabilities

• Eight individually bi-directional digital bits, each of which can be tri-stated orconfigured for input or output. One of the bits is used for control of vacuum if theModel TR-3-VALVE is configured into the System.

• Sink capability of 24 mA per bit. Source capability of 2.6 mA per bit. Each74LS-TTL bit is configured with a 10 KΩ pull-up resistor for TTL/CMOScompatibility.

• The System can be expanded by 96 bits of digital I/O by addition of an optionalCheckSum Model G-80 Digital I/O Module.

Guarding Capabilities

• General: Up to 6 guard points can be simultaneously selected.Each guard point can be externally sensed.

• AC/DC Voltage Guarding: Usable to ratios of approximately 100:1 (impedance ofmeasured component divided by impedance ofguarded path). Guard point is driven to low test pointpotential (ground).

• DC Current Guarding: Up to 15 mA of total guarding current. Guard point isdriven to potential of high test point.

• Unguarded Measurement: Since the System makes complex impedancemeasurements, even without guarding, it can makemeasurements of components with parallel impedanceswith a ratio down to 20:1. For example, when usingexternal sensing at 100 Hz, it can directly measureeither a 10 KΩ resistor or a 3 µF capacitor that aredirectly wired in parallel.


Zener Measurement Characteristics

• General: The Zener measurement function is available atTR-4-1D test points only. Use the Diode(Semiconductor) measurement technique if a TR-4-1Dis not installed.

• Technique: Source approximately 10 mA constant current. Thepositive test point is current limited with 12 Vcompliance and the negative test point is set to -10 V.Two terminal measurements are made up to 18 V.

• Accuracy: ± 5%, ± .3 V

• ApproximateMeasurement Speed:

2 mSec

External Verification

The Model TR-4 can be tested against external standards to confirm proper operation.The optional Model CM-3 provides hardware and software for this purpose. The externalcalibration may be executed semi-annually to assure full confidence.


Model TR-6 Functional Test System

Digital Multimeter

The DMM is used to make voltage and resistance measurements on the UUT. It canmake voltage measurements through the TR-6 test points (up to ± 250 volts) or throughthe TR-4 test points (up to ± 12 volts). Low resistance measurements, through the backpanel or TR-6 test points, augment the Model TR-4 MDA resistance measurementcapabilities.

DC Voltage Measurement

• Ranges: 200 mV, 600 mV, 2V, 6V, 20V 60V, 200V, 600V (maxinput 250V), autorange

• Accuracy: 0.5% of range

• Resolution: .05% of range

AC Voltage Measurement

• Ranges: 200 mV, 600 mV, 2V, 6V, 20V, 60V, 200V, 600V (maxinput 250V RMS), autorange

• Accuracy: 2% of range (40 Hz to 1 KHz)5% of range (1 KHz to 10 KHz)

• Resolution: 0.05% of range

• Input: AC or AC+DC Coupled

Resistance Measurement• Ranges: 2, 6, 20 Ω, autorange (including lead resistance)

• Resolution: .05% of range

• Accuracy: 3% of range (using zero offset)

• Ohms Source: 100 mA

DMM General• Voltage levels: The DMM can take fully floating differential

measurements on the ranges up to 6V. Neither inputcan exceed ± 8 from the computer chassis. On the 20Vand higher ranges, measurements areground-referenced.

• Measurement Speed: ~60mSec (AC readings and filtered DC readings~500mSec)


Counter/Timer

The counter/timer is used to measure frequencies and periods. It is typically used tomeasure UUT oscillator frequency and other UUT signal frequencies. Inputs can betaken from the unswitched back panel connector, the TR-6 switching, or through theTR-4 test points. The DMM input (usable to 50 KHz) can be accessed for low-leveldifferential inputs through the TR-6 test points. The optional Model TR-6-2 Interfacecan be used to buffer, and divide frequency signals in close proximity to the UUT.

• Frequency range: DC to 10 MHz (higher frequencies can be prescaled byModel TR-6-2 in fixture - see accessories)

• Channels: 2 plus DMM input

• Triggering: Programmable threshold -2.2V to +2.2V

• Input Level: 300 mV to 5 V (60 mV to 250 V through DMMchannel)

• Coupling: AC/DC

• Common: Ground-referenced (except on differential input rangesof DMM)

• FrequencyRanges: 5KHz, 50 KHz, 500 KHz, 5 MHz, 10 MHzResolution: .0015% of rangeAccuracy: .01% ± 2 counts

• Period:Range: 12.8 µS - 128 Sec

(in 8 decade ranges)Resolution: .0015% of rangeAccuracy: .01% ± 2 counts

• Totalize:Range: 1 to 65,535 counts

(up to 5MHz input)

• Pulse Width:Specifications Same as periodFunction: Start and stop slope selectable


Function Generator

The Function Generator is used to provide UUT stimulus. It can provide DC-V, sine andsquare waves. Both square wave output levels are separately programmable to providefull flexibility.

The stimulus is available at unswitched Model TR-6 back panel outputs, or at ModelTR-4 MDA test points. All three stimuli are available simultaneously with somelimitations (sine and square frequencies must match, square wave must beground-referenced). When switched through the Model TR-4 test points, the total pathresistance is 1 Kohm or less. Each function generator output can source up to 10mA intolow impedances, but the current/voltage is limited by the switch resistance.

• Functions: DC Voltage / Sine Wave / Square Wave

• Frequency Range: DC, 2 Hz - 40 KHz in 56 discrete steps

• Common: Ground-referenced

• Frequency Accuracy: .01%

• Harmonic Distortion: 1%

• Amplitude Accuracy: 1% of scale (DC)5% of scale (25 Hz to 1 KHz)10% of scale (1 KHz to 20 KHz)

• Sine Amplitude: 100 mV to 20 Vpp (.1dB steps)

• Square Wave Amplitude: Each level programmable from -10V to +10V (5mVsteps)

• DC V Amplitude: Programmable from -10V to +10V (5mV steps)

Power Outputs

The Model TR-6 makes PC-power available at the back panel connector. Each supply isfused on the TR-6 with a plug-in fuse. Fuse status is determined by system self-test.

The power outputs can be used to power UUTs with limited current requirements. Thepower outputs can be switched to the UUT with use of the undedicated relay switches onthe Model TR-6.

• Fixed outputs: +12V fused at 1A-12V fused at .1A+5V fused at 1AGND unfused


Digital I/O

The Model TR-6 provides digital capabilities which allow you to perform low-speeddigital input and output for test of UUT functionality. The digital I/O capability can alsobe used to drive relays or send and receive digital signals and switch closures controllingtest flow.

The standard Model TR-6 includes eight bits of digital I/O capabilities. These bits areavailable at the TR-6 back panel. Open-collector outputs can directly control externalrelays requiring up to 100mA when used with an external source. The digital outputs canbe left floating, or jumper-connected on the TR-6 through pull-ups to either +5V or+ 12V. The status of the eight bits can be read back by the system.

The digital I/O capability of the system can be expanded by 96 non-multiplexed bits withthe addition of a Model G-80 Digital I/O Module. Each bit on this module is individuallybidirectional and can sink up to 24mA.

When used in conjunction with Model TR-4-1D MPX modules, the system provides anadditional 16-bits of digital I/O per MPX module. On these modules, the first sixteen testpoints can be switched from general purpose analog MPX points to digital I/O pointswhen performing power-on testing. These points can source up to 2 mA and sink up to24 mA.

Basic TR-6 Digital I/O

• Bits: 8

• Direction: Output w/readback

• Logic Family: 5V TTL/LS/HC-MOS

• Outputs: Open-collector w/pull-up

• Distribution: Back panel connector only

• Sink/Source: Sink 100 mA. Source determined by pull-up resistor

• Pull-ups: 10K socketed pull-up to +5V or +12V


Undedicated Switching

The Model TR-6 provides four undedicated relays, available at the back panel, that canbe used for various testing needs such as switching power or other signals to the UUT.Typically, all of the signals from the Model TR-6 back panel connector are availableinside the test fixture. When a test fixture is built for a particular UUT, other TR-6signals and UUT test points can be connected to the undedicated relay connections foruse during the power-up tests.

In addition, an accessory 16-pin ribbon cable header on each Model TR-6-1 MPX Moduleprovides four relays for custom use.

• Undedicated Switches: 4 SPDT relays hardwired to back panel (12connections)

• Contact Rating: 250V, 1A, 30 VA resistive switched

• Isolation: 250V RMS

Test Point Switching

The Model TR-6 provides 16 relay-switched test points at its back panel. These testpoints can be expanded in 50-point increments by adding Model TR-6-1 Relay Modules(up to 6 TR-6-1 modules can be configured into a system).

The relay test points are used for UUT connections that exceed ± 12 volts with respect tothe computer chassis when power is applied to the UUT. The Model TR-6 can makeDMM and Counter/Timer measurements at these points. In addition, unguarded 2-wireModel TR-4 MDA measurements (e.g. resistance, capacitance and inductance) can bemade through these points.

• TR-6 Test Point Matrix: 16 relay-switched test points. Each TR-6 relay testpoint may be specified as a high or low for DMMmeasurement.

• Relay Expansion: The matrix may be expanded in 50-point incrementswith the Model TR-6-1 Relay Expansion Module.Each TR-6-1 module uses one full-length/full-heightPC slot.

• Model TR-4 Test Points: 2-wire measurements from the Model TR-4 can bemade through the Model TR-6 matrix. TR-6 sourceand measurement capability (except high-voltage &resistance measurement) is available from all TR-4 testpoints. Multiple sources can be active at TR-4 testpoints while making measurements.


Fixture Interface Module

The Model TR-6-2 Fixture Interface Module is designed to be used inside or near theUUT fixture to help support functional test operations. Connecting to the Model TR-6, itprovides a number of special capabilities with wire-wrap terminals for connection to theUUT and test point electronics. The basic module contains fundamental capabilities, andby setting jumpers and adding components as necessary, you can perform a number ofspecialized functions.

Under automated control of the Model TR-6, it provides power relays that can be used toswitch power supplies or other signals to the UUT, an interface to the counter/timer thatallows you to redrive or frequency-divide low-level UUT oscillator signals, dualinstrumentation amplifiers that can buffer and differentially amplify low level signals forthe DMM, two shunt locations for current monitoring and a bread-board area for customcircuitry.

The Fixture Interface includes stand-offs for easy mounting inside the fixture or on anyflat surface. The 50-pin ribbon cable from the Model TR-6 back panel can be directlyplugged into the Fixture interface, or when used inside a Model TR-3 vacuum test head,the special Model TR-6-3-THC plugs directly from the Fixture Interface to the inside ofthe fixture wiring block connected to the Model TR-6.

The basic Fixture Interface contains two power relays, connectors and interface circuits.You can install your own components to tailor it to your application or purchase kits fromCheckSum to populate it as necessary. The Model TR-6-RLY is an additional powerrelay (up to 8 can be installed), the Model TR-6-CT is the counter/timer interface, theModel TR-6-2-DMM is the DMM signal conditioner interface parts, and the ModelTR-6-2-SWO allows change-over of test points from one source to another (or isolation ofthe test points to eliminate loading).

Mechanical

• Size: 8" x 6.9" x 3"H (with relays installed).

• Mounting: 8 - 3/4" x #6 screws (not included)

Relay Switching

• Provisions for up to 8 DPDT (2 form-C) relays

• Contact rating 10A, 250VAC, 240VA

• Remotely controlled by Model TR-6

Counter/Timer Interface

• Inputs: 2 via wire-wrap or SMA connectors

• Frequency divider ratios: 2, 4, 8, 16

• Sensitivity: 100 mV


• Frequency response: 50 MHz

DMM Signal Conditioner Interface

• Dual 2-input buffer amplifiers

• Amplification ratios: 1 to 1000

• Max input voltage: ± 6 volts, differential

Switch-Over Module

The Model TR-6-2-SWO modules install in the Model TR-6 Fixture Interface Moduleallowing test points (close to the UUT) to be switched from one source to another (e.g.digital to analog) or to isolate pins to reduce capacitive loading.

• Each switch-over module installs in 2-power relay positions (for a maximum of 4switch-over modules with no power relays installed).

• Provides 17 ganged test point switch-overs per module.

External Verification

The Model TR-6 can be tested and calibrated against external standards to confirmproper operation and to provide full accuracy. This process uses an externalmultifunction calibrator and DMM and should be run semi-annually for bestperformance. Automated software is included for this purpose. See Chapter 10 of thismanual for details of this process.


Model TR-4/6 CheckSum MDA Software

• Media: 1.44 MByte 3 1/2" DS/HD Floppy Diskette

• MS and PC-DOS compatible (V2.0 and later). V6.0 or later recommended.

• Monochrome or color CGA, EGA, VGA and Hercules compatible

• Minimum memory requirement: 4 MB

Functions provided:

• Autolearn continuity from known-good sample

• Automatic selection of optimal test method

• Enter or edit UUT specification data

• Learn UUT connections, names and test tolerances from ASCII text file createdindependently

• Save learned file on disk

• Self-test each I/O pin and control circuitry

• Probe for test point identification with autonaming

• Execute steps interactively during programming with automatic tolerance and rangeassignment

• Assign special operator instructions

• Assign 8-character pin names

• Assign 12-character test names

• Print test results (all or fail only)

• Print test report for batch (yield report)

• Print specification data for UUT

• Print fixture wiring report with both sequential point number and alphabetic namesort

• Configure report destination and formatting options

• Enter up to 1000 test steps per test program

• Print Production Reports

• Print Pareto Reports

• Print X-bar/Sigma Control Reports


Partial List of Test Step Types

RES Measure resistanceCAP Measure capacitanceDIODE Measure semiconductor junction voltageINDUC Measure inductanceVOLT Measure voltageDMM Measure AC/DC voltageUCT Measure frequency/timeSQRV Square wave stimulusDCV DC voltage stimulusSINEV Sine wave stimulusRELAY Control TR-6/TR-6-1 RelaysGPIB Control IEEE-488 InterfaceZENER Measure Zener diodesCONT Opens/shorts continuity testDIGI/DIGO Digital input and outputPORTI/O PC port input and outputPAUSE Pause specified number of mSecDISCHARGE Discharge capacitorDISP Display message to operatorJMPx/LABEL Unconditional or conditional jumps to labels based on

measurements or keyboard inputEXEC Call user-written test step (.EXE or .COM file)CALL Call a subroutineBEEP Sound the speakerWAITK Wait for operator to press a specified key


Model RM-1 Relay Module

The Model RM-1 Relay Module general purpose Relay Module can be installed in anunused short 8-bit controller (PC) slot. It provides eight (four form-C and four form-A)undedicated relays rated at 1A (up to 250VAC) for switching UUT power and signals. Itincludes a backpanel 37-pin D-sub mating connector to accept your custom wiring. It iscontrolled by the Systems ‘PortO’ test step type.

Model-GPIB IEEE-488 Interface

The Model GPIB provides IEEE-488 interface capabilities for the test system. The GPIBmodule installs in an 8-bit PC short slot. It comes with a 2-meter cable for connection tothe first GPIB device, embedded firmware and software support, and drivers for otherlanguages.

Configuration

Model TR-4 Base System

• Includes: System Measurement Module (with no test points), CheckSoft Software andInstruction Manual.

• System Module: Includes measurement, guarding and digital I/O circuitry.

• Configuration: Requires one full-length, AT-height slot.

• Can be expanded to 200 through 1600 test points with MPX Modules.

Model MPX-3 Modules

• 200 test points per MPX Module (or 100 externally sensed test points).

• Each point can be designated as high or low test point, external sense point, a guard,or an external guard sense point.


• Zener diode measurement capability. Can source up to 10 mA across diode formeasurement of Zener diodes up to 18VDC. (Requires use of Model TR-4 Systemmodule).

• Includes four 50-pin ribbon cables that extend approximately 30" from the rear of thecomputer.

• Each module requires one full-length, AT-height slot (uses 8-bit bus).

Model TR-4-1D MPX Modules

Same as MPX-3 with additional features:• Sixteen bits digital I/O. Test points one through sixteen can be switched (under

program control) between standard analog I/O points or dedicated digital IO points.

Model TR-6 Base System

• Includes System Module, 50-pin ribbon cable, CheckSoft Software and InstructionManual.

• System Module: Includes DMM, Counter/Timer, Function Generator, 16 Relay testpoints, 4 undedicated relays, fused power outputs and 8 digital driver bits.

• Configuration: Requires one full-length, AT-height slot.

• Test point count can be expanded with Model TR-4-1, TR-4-1D or TR-6-1 MPXModules.

Model TR-6-1 Relay MPX Modules

• 50 test points per Relay MPX Module.

• Each point can be designated as high or low measurement test point for UCT, DMM,or 2-wire TR-4 measurements (no sourcing).

• Includes 50-pin ribbon cable that extends approximately 30" from the rear of thecomputer.

• Each module requires one full-length, AT-height slot (uses 8-bit bus).


Controller Requirements

• Minimal controller configuration includes 486 processor, monochrome graphics, harddisk and 4 MByte RAM memory. Software is compatible with color or monochromemonitors with graphics capability.

• A typical controller, such as the CheckSum Model T-120, can be configured for up to1000 test points internally. Larger configurations require the use of an controllerwith additional slots such as the CheckSum Model T-120-IC Industrial Controller.Contact CheckSum for details.

• When purchased with a controller, the System is shipped fully integrated and tested.

General Notes

• Typical accuracies shown are when measuring isolated components. Accuracies maydegrade depending on surrounding circuitry.

• All speeds shown derived with 33 MHz controller. Speeds for most MDA DC-basedtesting operations are roughly proportional to CPU speed.

• To obtain stated typical Model TR-4 accuracies when using AC techniques,low-impedance measurements (less than about 1 KΩ) may require external sensing.This compensates for typical 15 Ω lead resistance beyond internal sense points.


Configuration

A CheckSum Test System is configured for your particular application from the followingSystem elements:

Core SystemModel TR-4 MDA Base System with Measurement Electronics, System

Software LicenseModel MPX-3-200 Solid-state MPX Module with 200 Test Points and Cabling

(includes Zener testing capability)Model TR4-1D Solid-state MPX Module with 200 Test Points and Cabling

(includes 16-bits digital I/O)Model TR-6 Functional Test Base System with Measurement

Electronics, System Software LicenseModel TR6-1 Relay MPX Module with 50 Test Points and CablingModel TR6-2 Fixture Interface for power switching and UUT signal

isolation and conditioning.Test Controller (PC) OptionsModel T-120 Desktop ControllerModel T-120-IC Industrial Controller with Additional SlotsFixture System OptionsModel GS-850 Edge Connector Fixture SystemModel AB1-AB6 Adapter Boards for Model GS-850 Fixture SystemModel TR-5-812 Bed-of-Nails Mechanical Fixture System (8" x 12")Model TR-5-1216 Bed-of-Nails Mechanical Fixture System (12" x 16")Model TR-5-1620 Bed-of-Nails Mechanical Fixture System (16" x 20")Model TR-3A Bed-of-Nails Vacuum Fixture SystemModel TR-3-1 Fixture Wiring/ConnectorsModel TR-3-2 Test Head Wiring BlockModel TR-3-1216 12" x 16" Test HeadModel TR-3-1620 16" x 20" Test HeadModel TR-3-2024 20" x 24" Test HeadOptional AccessoriesModel T-120-2P PrinterModel T-120-PTRC Expansion ChassisModel T-120-3 Foot SwitchModel G-80 Digital I/O ModuleModel RM-1 Relay ModuleModel GPIB IEEE 488 Interface


Theory of Operation

This chapter describes how the CheckSum Model TR-4 and TR-6 Test Systems makemeasurements. The first section describes the Model TR-4 MDA System. The secondsection describes the Model TR-6 Functional Test System. The final section providesguidelines for making effective measurements.

Model TR-4 Theory of Operation

Overview

The CheckSum Model TR-4 Manufacturing Defects Analyzer has been designed toeffectively measure a variety of components, both out-of-circuit and in-circuit. To dealwith the variety of in-circuit conditions that can occur, the System offers severalmeasurement methods and options.

This section describes these techniques and gives you an idea about how to best use themto solve testing problems. For most measurements, the System can automatically choosethe best technique and it is not necessary for you to know the details of themeasurements. However, if you want to obtain optimum results on problemmeasurements or use to guarding, you should read and understand this section.

The System contains two separate measurement modes:

Current Mode - Uses a DC constant-current stimulus for taking measurements.

Voltage Mode - Uses either AC or DC voltage stimulus for taking measurements.

Each of these measurement modes is described separately. Finally, some guidelinesabout how to test in general are included. This section also gives tips on how to testvarious specific components.


Current Mode

Overview

The Current Mode uses a precision constant-current source in conjunction with a voltagemeasurement capability to effectively test resistors, semiconductor junctions, andcapacitors. Each is discussed below.

The System can provide DC constant-current in five-decade steps from .1 µA to 1 mA andhas two voltage measurement ranges of 200 mV and 2 V full range. Betweencombinations of source currents and measurement ranges, the System can provide anumber of unique measurement ranges. Typically, 2 V full-range values provide betteraccuracy. However, when measuring in-circuit, it may be necessary to use 200 mV rangesto prevent diode junctions from turning on and adversely affecting the readings.

Figure 4-1 - Current Mode Block Diagram

As shown in Figure 4-1, the System is connected in a four-wire Kelvin configuration sothat the voltage is sensed on the component side of the solid-state relays that provide theconstant-current to the unknown resistance. The Kelvin technique takes advantage of thefact that you can make an accurate voltage measurement through a resistance (such asswitches in the measurement side) as long as the input impedance of the measurementcircuit is very high. Since the current through the sense leads is very small, there is

MeasureVoltageRx

CxQx

CurrentSource


essentially no voltage drop across the switches. Consequently, the resistances of theswitches are not significant, allowing accurate voltage measurements to be made.

The paths from the internal sense point to the end of the cables can add up toapproximately 15 Ω to the resistance on each test point. This resistance, shown as Rp inFigure 4-2, is measured during System self-test/calibration and is automatically subtractedfrom readings that you take.

If you need to take precise readings of low impedances, you can instruct the System toremotely sense at the assembly that you are testing. To use this technique, wire twoadditional test points to the fixture measurement point. This will effectively eliminate theeffect of all of the resistance in the switching and lead paths. Figure 4-2 shows howexternal sensing can be used to eliminate virtually all of the extraneous impedances in themeasurement path.

Figure 4-2 - External Sensing Diagram

Testing Resistors

The Current Mode measures resistors by applying a constant-current source to theunknown resistance and then measuring the voltage drop across the unknown resistance.From the known current and measured voltage, resistance is calculated with Ohm’s law.

Internal Sense (+)

RpExternal Sense (+)

MeasureVoltageRx

CxQx

RpExternal Sense (-)

CurrentSource

Rp = Lead/Path resistance (2-15 Ohms)

Internal Sense (-)


Using the various current and voltage combinations available, the System provides tenresistance measuring ranges with mid-scale readings from 100 Ω to 10 MΩ. Dependingon the range, full-range voltage is either 2 V or 200 mV.

The System can be configured to provide variable delays between the time when thecurrent source is applied and when the measurement is taken. You may also specify howmany samples are averaged in each measurement range. If the assembly that you aretesting has capacitors that can become charged during testing, you can specify that theSystem check for a voltage across the resistor prior to making the measurement, and if so,discharge the point.

Testing Capacitors

The Current Mode tests for capacitors by applying a constant current, then measuring atsmall precise time intervals to determine the rise time of the voltage as the capacitorcharges. From the voltage change, the time, and the amount of constant-current applied,the capacitance can be computed.

For capacitance measurements the Model TR-4 uses the same constant-current sourceand voltage measurement circuitry used for measuring resistance. However, whenmeasuring capacitance, the System measures a number of samples at precise intervals for100 mSecs. From the gathered information, the System computes the capacitance. Priorto each measurement, the System discharges the point as necessary.

Both 2V and 200mV full-range voltages and 1 mA to .1 µA constant-current sourceranges can be selected to measure capacitance.

Testing Diodes/Semiconductors

The Current Mode measures diodes in a fashion similar to that of testing resistors. Aselectable constant-current source (1 mA to .1 µA) is connected to the semiconductorjunction, then the voltage drop across the junction is measured. You can also measurezener diodes up to about 10 volts with diode measurements.

Guarding

The Model TR-4 allows you to apply guard points to help eliminate the effect thatparallel components have on the measurement. Consider the circuit shown in Figure 4-3.If you measure Rx, you are also measuring the parallel combination of Ry + Rz. Usingguarding, you can eliminate (or reduce) the effects of Ry and Rz from the measurement.


Figure 4-3 - Circuit with Parallel Components

Figure 4-4 shows the same circuit with current guarding applied. The guard point, appliedto the junction of Ry and Rz, applies current to bring the guard point to the same voltagepotential as the (+ ) test point. Once this is achieved, there is little or no current flowthrough Ry. Consequently, all of the source current flows through Rx, and as a result, theeffects of Ry and Rz are eliminated from the measurement.

You can apply up to six simultaneous guard points with a current mode measurement.Each of the guard points can be externally sensed to more accurately cancel the currentsof the parallel resistances. The System can apply up to 15 mA of guard current for a DCcurrent measurement.

Figure 4-4 - Circuit with Current Guarding

(+) test point

Ry+

-

Rx

Rz

Guard point

(-) test point

(+) test point

Ry

Rx

Rz

(-) test point


Voltage Mode

Overview

The Voltage Mode provides the capability to measure resistors, capacitors and inductors.It can measure using DC voltage or AC frequencies of 100 Hz and 1 KHz as stimulus.Figure 4-5 shows a block diagram of the voltage System.

Figure 4-5 - Voltage Mode Block Diagram

Compared to the Current Mode, the Voltage Mode provides advantages for manyin-circuit measurements:

a. Since complex measurements are taken, the System can provide better measure-ments when connected to circuits that contain both resistive and inductive orcapacitive components.

b. Capacitance readings taken at 1 KHz are much faster than capacitance measure-ments taken with the Current Mode.

c. Measurements of smaller capacitances are possible.

d. Ability to measure inductance is available.

The voltage source can provide either 2 V or 200 mV full-range stimulus of DC, 100 Hz,or 1 KHz. The AC signals are low-distortion sine waves. Internal output impedance of

SourceVoltage

RxCxIx

MeasureVoltage

-+

CurrentMeasure


the stimulus system is about 600 Ω, limiting the current and voltage at the component tobe tested. Maximum current through the tested component will not exceed about 3 mA.

Once the stimulus signal is applied, the System measures the voltage drop across theunknown component. Using other circuitry, the System then measures the current toground (which is the (-) measurement test point) through the unknown component. Fromthis information, the impedance of the component being measured can be calculated viaOhm’s law.

In AC-voltage measurements, the System also measures the 90-degree quadrature voltageand current components through the unknown. Knowing the voltage and current bothin-phase and in 90-degree phase, the System can calculate the capacitive, inductive, andresistive components of the unknown impedance.

Testing Resistors

When taking resistance measurements with AC, measurements that have an inductivecomponent are calculated using a series LR calculation model as shown in Figure 4-6.For other AC-resistance measurements the System uses the parallel RC model as shownin Figure 4-7.

Figure 4-6 - Series LR Model

The System can also measure resistors using DC voltage. When measuring resistors withthis mode, only two in-phase readings (voltage and current) are made, then the resistancecomputed using Ohm’s law.

The System can measure resistance values from 0 to 19 MΩ.

Figure 4-7 - Parallel RC Model


Testing Capacitors

Small capacitance values (less than 1 µF) use the parallel RC model shown in Figure 4-7.Large capacitance values use the series RC model shown in Figure 4-8. The effectivemeasurement range is 0 pF - 2,000 µF at 1 KHz and 10 pF - 20,000 µF at 100 Hz.

Figure 4-8 - Series RC Model

Testing Inductors

Inductors use the series LR model shown in Figure 4-6. The effective measurementrange of inductors is 6 µH to 1000 H.

Use of Offset

The AC stimulus from the System can be offset. If the System is not offset, the sourcesignal (+ test point) is symmetrical above and below the potential of the (-) test point. Ifpositively offset, the signal is entirely above potential of the (-) test point, and ifnegatively offset, entirely below the potential of the (-) test point. The effects ofoffsetting on the output signal are shown in Figure 4-9.

Figure 4-9 - Offset

Offsetting can be valuable when measuring across diodes and sometimes can providebetter readings when measuring polarized capacitors. Offset operation is slower thannormal operation. Since offsetting can effectively leave a charge on the component beingtested, it may be necessary to discharge it before other measurements are taken.

No Bias Positive Bias Negative Bias

0V


Frequency Selection

You may choose between DC, 100 Hz, and 1 KHz when using the Voltage Mode. Thissection discusses the theoretical reasons for choosing the frequency.

For purposes of speed, whenever practical, 1 KHz should be used in place of 100 Hz sincemeasurements at 1 KHz are about 10 times faster than 100 Hz measurements. In mostcases, the speed of capacitor measurements taken with the Current Mode are slower than1 KHz measurements and faster than 100 Hz measurements.

From a measurement standpoint, selection of 100 Hz vs 1 KHz is a choice based primarilyon the value of the component being measured and its surrounding circuitry.

For small inductors and small capacitors, use 1 KHz. For large inductors and largecapacitors, use 100 Hz.

When measuring components that have other components in parallel, you should use thefrequency that makes the impedance of the unknown component small compared to thesurrounding components.

For example, consider that you are measuring a 10 KΩ resistor in parallel with a .1 µFcapacitor. The impedance of the capacitor depends on the frequency. As you probablyrecall:

For capacitors: XC = 1

2 π F C

For inductors: XL = 2 π F L

In our hypothetical measurement of the 10 KΩ resistor in parallel with a .1 µF cap, thecapacitor’s impedance is:

Frequency Impedance100 Hz 15.9 KΩ1000 Hz 1.59 KΩ

You want to minimize the effect of the parallel capacitance upon the resistor, therefore100 Hz is better since it will decrease the parallel load. If you were measuring thecapacitor, you would want to use 1 KHz since it makes the capacitor more dominant withrespect to the resistor.

Guarding

The Model TR-4 allows the use of voltage guarding. Guarding is a technique by whichyou can reduce the effect of parallel components upon the measurement.


Consider the circuit shown in Figure 4-3. If we measure Rx, we will actually measure thecombination of Ry + Rz in parallel with Rx.

If we add a guard point, as shown in Figure 4-10, we can minimize the effects of theparallel resistance of Ry and Rz.

Figure 4-10 - Circuit with Voltage Guarding

In the Model TR-4 Voltage Mode, guard points tie the guarded circuit point to groundpotential. When the guard is active, it forces the top of Rz and the (-) Test Point to be atthe same voltage potential. As a result, no current can flow through Rz and consequentlyall of the current that we measure at the (-) Test Point flows through Rx. Since we haveaccurately measured the current through Rx and we can accurately measure the voltageacross Rx, we can determine its value with the effects of Ry and Rz guarded out.

The Model TR-4 allows you to have up to six simultaneous guard points. This allows youto eliminate the current paths from several surrounding circuits. Each of the six guardpoints can be externally sensed at the UUT to provide the most effective guarding.

You can guard out resistors, capacitors or inductors with the System. The effectiveness ofguarding increases as does the impedance of the component between the (+) test pointand the guard point (Ry in the previous example). If the impedance of this component issmall (less than 1/100 the value of Rx, for example), guarding is not likely to be highlyeffective. In the example (Figure 4-10), if Rz is a larger resistance than Ry, you couldimprove the effectiveness of guarding by reversing the polarity of the measurement.

Note that as you add guard points to the Model TR-4 Voltage Mode, the amplitude of thestimulus signal becomes smaller and smaller. If the guarded impedances are small, youmay eventually get to the point where the stimulus is so small that repeatability of thereadings decreases.

(+) test point

Ry

Guard pointRx

Rz

(-) test point


Model TR-6 Theory of Operation

Overview

The Model TR-6 Functional Test System allows you to power-up your unit-under-test(UUT), then apply stimulus and make measurements to ensure proper UUT operation.

Typically, the Model TR-6 Functional Test System is used in conjunction withCheckSum’s Model TR-4 MDA System. When this is the case, the MDA system is firstused to passively (no UUT power applied) test for proper assembly and no opens orshorts that could cause damage once power is applied. Once this testing has successfullybeen completed, the Functional Test System can apply power, provide stimulus, and makeactive measurements.

The combined Systems provide a number of capabilities and shared elements. Thissection describes various aspects of using the System with respect to common elements.It also describes some global aspects of using the Model TR-6 Functional Test System.

Chapter 11 describes the test step types that are specific to the Model TR-6.

System Switching Overview

System test point switching allows you to use Model TR-4-1 solid state test points (testpoints 1-1600), relay test points on the Model TR-6 (test points 1601-1616) or from theModel TR-6-1 Relay MPX Modules (test points 1651-1950).

The Model TR-6 also allows you to directly use its stimulus or measurement capabilitiesfrom its back panel. If you want to use this direct path, specify a "from (-)" test point of1625. Doing so eliminates any other internal switching that might otherwise be done.Note that the back panel inputs and outputs are always active (not disconnected)regardless of other system activity. Consequently, if you connect them directly to a testpoint, make sure that stimulus/measurements routed to these points during other parts ofthe test sequence will not cause problems.

When wiring the test fixture, special care must be used when wiring test points that canexceed plus or minus 12 volts with respect to the controller (PC) chassis when the UUT ispowered up. These points must be wired to the Model TR-6(-1) relay test points toprevent erroneous measurements and damage to the test system. However, wheneverpossible use Model TR-4-1 test points since these are the most flexible. The TR-4-1 testpoints can be used for continuity tests, source, sense and do guarded measurements whilethe Model TR-6 test points are for basic 2-wire measurements only).


The TR-6 relay switching is also used in place of the TR-4 switching for taking lowresistance measurements with the Model TR-6. Since the TR-6 DMM uses 100 mA, theTR-4 switching would be damaged by its use and compliance voltages would be exceeded.

System Measurement Switching

Both the relay switching of the Model TR-6(-1) or the solid-state switching of the ModelTR-4-1 can be used to make UUT measurements. These measurements can be madewith the Model TR-6’s DMM or UCT or the Model TR-4 MDA’s measurement circuitryfor resistance, capacitance, inductance or DC voltage measurements.

UUT measurements using the TR-6 switching are 2-wire only. Therefore, guarded orexternally sensed measurements are not practical through these points, although TR-4measurements taken through TR-6 test points can be externally sensed through TR-4 testpoints.

System Source Switching

The Model TR-6 has internal sources for generating sine waves (SINEV), square waves(SQRV) and dc voltages (DCV). In addition, there are provisions for switching anexternal signal (EXTIO) for sourcing or measuring with an external device. Thesesources are available at the TR-6 back panel, or they can be switched into the ModelTR-4-1 solid state switching. They are not available at the Model TR-6(-1) relayswitching. If it is necessary to apply one of these sources to a test point that cannot bewired into the Model TR-4-1, you can provide wiring for the source to the UUT pointthrough one of the Model TR-6’s undedicated relays.

The Model TR-6 sources are ground-referenced. The ground is ultimately connected tothe chassis of the controller (PC). The "from (-)" test point used for supplying sources areconnected back to this ground.

System sources are disconnected when the source test title is specified as RESET (ineither upper or lower case), or when the same source is connected to another destination.The System can provide each source to multiple destinations if the test program uses aFLAGS (8) command to enable multiple sourcing or a FLAGS (4) to disable multiplesourcing. The sources are all reset when the system is powered up, when a CONT or ICStest is performed, and before and after each complete spec file is executed.

The Model TR-4 allows up to six guard points at one time (each of which can be remotelysensed. When one or more sources are programmed (and not reset), only three guardpoints can be active simultaneously. The software automatically ignores the last threeguard points if present.


UUT Power Switching

The Model TR-6 has the ability to apply power to the UUT. Applying power can beaccomplished in several ways depending on the requirements of the UUT.

For low-power UUTs that require +12 V or 5 V (up to 1A) or -12V (up to 100mA), theSystem provides fused outputs from the controller’s (PC’s) power supply. These can beconnected to the Model TR-6’s undedicated switching for connecting power and groundto the UUT.

For medium power UUTs (those requiring up to about 1 amp), the System’s undedicatedrelays can be used to switch the power to the UUT via an external power supply. Thereare several ohms of internal resistance present in this switching, so some voltage drop willoccur when switching more than a few milliamps.

For higher power UUTs, the TR-6’s digital output capability can be used to directlyswitch external power relays. The open-collector digital outputs sink up to 100 mA and,as such, can power fairly large power relays.

As a final method of switching higher UUT power, the Model TR-6-2 Fixture Interfacecontains power switching relays that are suitable for UUTs requiring up to 10 amps.

Note that you should switch both power and ground to the UUT since the Model TR-4MDA System relies on the UUT to be floating during MDA testing operations.

- WARNING -Because of the extreme hazard to operators, you should avoidapplying line power and other high voltages to the UUT during test.As an alternate, switch DC into the output of the AC power supplyon the UUT.

System Source Interdependency

The Model TR-6 has the ability to provide simultaneous stimulus channels, however,there are some interdependencies. In the case of interdependencies, the last programmedvalue has priority. These include:

1. If a square wave (SQRV) is specified with a non-zero low-limit, the DC voltage(DCV) output is used as the lower value. Therefore, the stimulus value for thefirst voltage of the square wave and the DCV output will be the same. If the alter-nate DCV output (range = 2) is used, it disables the square wave output entirelyand replaces it with the specified DC voltage signal.

2.


The square and sine wave generation (SINEV/SQRV) use the same frequencygeneration circuitry, therefore the frequency must be the same for both if they aresimultaneously used.

AC Source Frequencies Available

The following frequencies are available when generating sine and square waves:

40KHz, 20KHz, 13.3KHz, 10KHz, 8KHz, 6.67KHz, 5.71KHz, 5KHz, 4.44KHz, 4KHz,3.64KHz, 3.33KHz, 3.08KHz, 2.85KHz, 2.67KHz, 2.5KHz, 2KHz, 1.33KHz, 1KHz, 800Hz,667Hz, 571Hz, 500Hz, 444Hz, 400Hz, 364Hz, 333Hz, 308Hz, 285Hz, 267Hz, 250Hz,200Hz, 133Hz, 100Hz, 80Hz, 67Hz, 57Hz, 50Hz, 44Hz, 40Hz, 36Hz, 33Hz, 31Hz, 29Hz,27Hz, 25Hz, 20Hz, 13Hz, 10Hz, 8Hz, 7Hz, 6Hz 5Hz, 4Hz, 3Hz.

Digital Input/Output

The Model TR-6 directly accommodates eight bits of digital I/O via its System Module.The eight bits consist of open-collector drivers that can be used to control external relaysthat require currents of up to 100 mA. The module supports the installation of on-boardpull-up resistors that make the digital byte appear as + 5V or + 12V digital logic.Alternatively you can use an external pull-up source. Digital input signals of up to 12volts can also be read back (at TTL logic thresholds). This digital I/O is controlled withthe DIGI and DIGO test types (see Chapter 11).

When used with a Model TR-4 MDA System, an additional byte of digital data on theModel TR-4 System module is also available. Model TR-4 digital I/O is controlled withthe DIGA, DIGI and DIGO test types (see Chapter 11).

The TR-6 DCV command (see Chapter 11) can be used to provide logic levels to severaltest points simultaneously. The (-) test point serves as a digital low and the (+ ) testpoint, when programmed to + 5V serves as a digital high level. Up to 16 simultaneoussource points can be used. Under normal circumstances, the System disconnects previoustest points connected to the same source (e.g. DCV) when a new stimulus is applied.However, with use of the FLAGS test step, you can have the System allow multiplestimulus points from the same source (FLAGS range = 8). The FLAGS test type with arange of 4 sets the System back to single source mode. The source can be disconnectedwith a RESET of the desired source.

Note

When using the DCV command for digital control, be advised that the Sys-tem will disconnect the stimulus for short periods of time between tests aspart of the hardware reset process. Because of this you should not useDCV stimulus to digital points that are clocks or are edge-sensitive.


When the System is configured with Model TR-4-1D MPX modules, you can multiplexthe first 16 test points per TR-4-1D module between standard analog I/O and digital I/Ounder software control. These points can be wired into digital nodes on the UUT tosupply digital testing. These test points are configured as analog or digital inputs andoutputs with the DIGA test type. Use the DIGO and DIGI test types to then change thebits. See chapter 11 for detailed information about these test types.

A G80 Overdrive Module (G80-ODM) is an available accessory for overdrive of signaland control lines to extend the LOGIC test capability of a system. The overdrive moduleprovides high current drivers useful to temporarily force a logic level on a net which alsois driven by another active output. The automatic use of overdrive is included in theLOGIC test. The G80-ODM can be controlled by TTL outputs and can be directlyconnected to a G80 cable.

Grounding

The Model TR-6 provides two grounds, analog and chassis. These are connected togetherinternally in the Model TR-6 module. During fixturing, you will normally leave bothgrounds separated.

For analog sourcing and measuring, the analog ground is used. By being separated fromthe chassis ground, noise and ground loops are minimized.

Model TR-6 analog sources and digital I/O are referenced to the computer chassisground. DMM inputs are floating (to within 8 volts of computer chassis) for the lowerranges (up to 6 V), and referenced PC chassis for higher r

Documents

CheckSum TR-4/6 Instruction Manual · Model TR-4/6 Automated Test System INSTRUCTION MANUAL CheckSum, Inc. P.O. Box 3279 Arlington, WA 98223 (360) 435-5510 Web Site: