Data Translation DT9828 User Manual

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UM-24984-A

DT9828 User’s Manual

Title Page

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Copyright Page

First Edition January, 2013

Data Translation, Inc. 100 Locke Drive Marlboro, MA 01752-1192 (508) 481-3700 www.datatranslation.com Fax: (508) 481-8620 E-mail: info@datx.com

Information furnished by Data Translation, Inc. is believed to be accurate and reliable; however, no responsibility is assumed by Data Translation, Inc. for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent rights of Data Translation, Inc.

Use, duplication, or disclosure by the United States Government is subject to restrictions as set forth in subparagraph (c)(1)(ii) of the Rights in Technical Data and Computer software clause at 48 C.F.R, 252.227-7013, or in subparagraph (c)(2) of the Commercial Computer Software - Registered Rights clause at 48 C.F.R., 52-227-19 as applicable. Data Translation, Inc., 100 Locke Drive, Marlboro, MA 01752.

Data Translation® is a registered trademark of Data Translation, Inc. DT-Open Layers Library QuickDAQ

, DataAcq SDKTM, OMNI CDTM, LV-LinkTM , and

are trademarks of Data Translation, Inc.

, DT-Open Layers for .NET Class

All other brand and product names are trademarks or registered trademarks of their respective companies.

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Radio and Television Interference

This equipment has been tested and found to comply with CISPR EN55022 Class A and EN61000-6-1 requirements and also with the limits for a Class A digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications. Operation of this equipment in a residential area is likely to cause harmful interference, in which case the user will be required to correct the interference at his own expense.

Changes or modifications to this equipment not expressly approved by Data Translation could void your authority to operate the equipment under Part 15 of the FCC Rules.

Note: This product was verified to meet FCC requirements under test conditions that included use of shielded cables and connectors between system components. It is important that you use shielded cables and connectors to reduce the possibility of causing interference to radio, television, and other electronic devices.

FCC Page

Canadian Department of Communications Statement

This digital apparatus does not exceed the Class A limits for radio noise emissions from digital apparatus set out in the Radio Interference Regulations of the Canadian Department of Communications.

Le présent appareil numérique n’émet pas de bruits radioélectriques dépassant les limites applicables aux appareils numériques de la class A prescrites dans le Règlement sur le brouillage radioélectrique édicté par le Ministère des Communications du Canada.

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Table of Contents

About this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Intended Audience. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

How this Manual is Organized . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Conventions Used in this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Related Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Where To Get Help. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Chapter 1: Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Supported Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Getting Started Procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Chapter 2: Installing a Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Unpacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Attaching Modules to the Computer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Connecting Directly to the USB Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Connecting to an Expansion Hub . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Configuring the Device Driver. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Chapter 3: Wiring Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

General Wiring Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Connecting Thermocouple Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Connecting Voltage Input Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Connecting Current Loop Inputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Connecting Digital Input Signals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Connecting Digital Output Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Chapter 4: Verifying the Operation of a Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Selecting the Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Thermocouple Measurement Example. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Configure the Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Configure the Parameters of the Acquisition Config Window . . . . . . . . . . . . . . . . . . . 46

Configure the Appearance of the Channel Plot Window . . . . . . . . . . . . . . . . . . . . . . . . 48

Configure the Appearance of the Channel Display Window. . . . . . . . . . . . . . . . . . . . . 50

Configure the Appearance of the Statistics Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Position the Windows. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Start the Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

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Contents

Chapter 5: Principles of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Analog Input Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Analog Input Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Specifying a Single Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Specifying One or More Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Cold Junction Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Open Thermocouple Detection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Input Ranges and Gains. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Input Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

A/D Sample Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Input Trigger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Analog Input Conversion Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Single-Value Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Continuous Scan Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Filtering. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Error Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

Digital I/O Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Digital Input Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Digital Output Lines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Resolution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

Operation Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

Chapter 6: Supported Device Driver Capabilities. . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Data Flow and Operation Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Buffering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

Triggered Scan Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

Data Encoding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

Thermocouple and RTD Support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

IEPE Support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Strain Gage Support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

Start Triggers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

Reference Triggers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

Clocks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

Counter/Timers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

Tachometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

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Chapter 7: Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

About Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

Running the Calibration Utility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

Calibrating the Voltage Offset and Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

Calibrating the CJC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

Chapter 8: Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

General Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

If Your Module Needs Factory Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

Appendix A: Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

Basic Module Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94

Thermocouple Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

System Temperature Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

Temperature Measurement Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

Thermocouple Noise Calculation Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

Voltage Measurement Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

Input Signal Bandwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

Digital I/O Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

Isolation and Protection Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

Power, Physical, and Environmental Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

Terminal Block Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104

Regulatory Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

Contents

Appendix B: Pin Assignments and LED Status Indicators . . . . . . . . . . . . . . . . . . . 107

Analog Input Screw Terminal Block (TB1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

Digital I/O Screw Terminal Block (TB2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109

USB Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

LED Status Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

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Contents

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The first part of this manual describes how to install and set up your DT9828 module and device driver, and verify that your module is working properly.

The second part of this manual describes the features of the DT9828 module, the capabilities of the DT9828 Device Driver, and how to program the DT9828 module using the DT-Open Layers for .NET Class Library™ software. Troubleshooting and calibration information is also provided.

Note: For information on checking system requirements, installing the software, and viewing the documentation, refer to the README file on the OMNI CD.

For more information on the class library, refer to the DT-Open Layers for .NET Class Library User’s Manual. If you are using the DataAcq SDK or a software application to program your device, refer to the documentation for that software for more information.

Intended Audience

About this Manual

This document is intended for engineers, scientists, technicians, or others responsible for using and/or programming the DT9828 module for data acquisition operations in the Microsoft® Windows® XP, or Windows Vista®, Windows 7, or Windows 8 operating system. It is assumed that you have some familiarity with data acquisition principles and that you understand your application.

How this Manual is Organized

The manual is organized as follows:

• Chapter 1, “Overview,” describes the major features of the DT9828 module, as well as the supported software and accessories for the modules.

• Chapter 2, “Installing a Module,” describes how to install a DT9828 module.

• Chapter 3, “Wiring Signals,” describes how to wire signals to a DT9828 module.

• Chapter 4, “Verifying the Operation of a Module,” describes how to verify the operation of the DT9828 module with the QuickDAQ application.

• Chapter 5, “Principles of Operation,” describes all of the features of the DT9828 module and how to use them in your application.

• Chapter 6, “Supported Device Driver Capabilities,” lists the data acquisition subsystems and the associated features accessible using the DT9828 Device Driver.

• Chapter 7, “Calibration,” describes how to calibrate the analog input circuitry of the DT9828 module.

• Chapter 8, “Troubleshooting,” provides information that you can use to resolve problems with the modules and the device driver, should they occur.

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About this Manual

Conventions Used in this Manual

Related Information

• Appendix A, “Specifications,” lists the specifications of the modules.

• Appendix B, “Pin Assignments and LED Status Indicators,” shows the pin assignments for the connectors and screw terminals on the modules, and describes the LEDs on the modules.

• An index completes this manual.

The following conventions are used in this manual:

• Notes provide useful information or information that requires special emphasis, cautions provide information to help you avoid losing data or damaging your equipment, and warnings provide information to help you avoid catastrophic damage to yourself or your equipment.

• Items that you select or type are shown in bold.

Refer to the following documents for more information on using the DT9828 module:

• Benefits of the Universal Serial Bus for Data Acquisition. This white paper describes why USB is an attractive alternative for data acquisition. It is available on the Data Translation web site (www.datatranslation.com).

• QuickDAQ 2103 User’s Manual (UM-24774). This manual describes how to create a QuickDAQ application to acquire and analyze data from a DT9282 module.

• DT-Open Layers for .NET User’s Manual (UM-22161). For programmers who are developing their own application programs using Visual C# or Visual Basic .NET, this manual describes how to use the DT-Open Layers for .NET Class Library to access the capabilities of Data Translation data acquisition devices.

• DataAcq SDK User’s Manual (UM-18326). For programmers who are developing their own application programs using the Microsoft C compiler, this manual describes how to use the DT-Open Layers DataAcq SDK acquisition devices.

• DAQ Adaptor for MATLAB (UM-22024). This document describes how to use Data Translation’s DAQ Adaptor to provide an interface between the MATLAB Data Acquisition subsystem from The MathWorks and Data Translation’s DT-Open Layers architecture.

• LV-Link Online Help. This help file describes how to use LV-Link™ with the LabVIEW™ graphical programming language to access the capabilities of Data Translation data acquisition devices.

to access the capabilities of Data Translation data

• Microsoft Windows XP, Windows Vista, Windows 7, or Windows 8 documentation.

• USB web site (http://www.usb.org).

• Omega Complete Temperature Measurement Handbook and Encyclopedia®. This document, published by Omega Engineering, provides information on how to linearize voltage values into temperature readings for various thermocouple types.

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Where To Get Help

Should you run into problems installing or using a DT9828 module, the Data Translation Technical Support Department is available to provide technical assistance. Refer to Chapter 8 for more information. If you are outside the United States or Canada, call your local distributor, whose number is listed on our web site (www.datatranslation.com).

About this Manual

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About this Manual

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Overview

Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Supported Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Getting Started Procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Page 14

Chapter 1

Features

The DT9828, shown in Figure 1, is a low-cost thermocouple and voltage input module for the Universal Serial Bus (USB) (Version 1.1, 2.0, or 3.0).

Figure 1: DT9828 Thermocouple and Voltage Module

The key features of the DT9828 module are as follows:

• 8 differential analog inputs for thermocouple or voltage input measurements

• Support for B, E, J, K, N, R, S, and T thermocouple types

• One cold junction compensation (CJC) circuit for all thermocouple inputs

• Open thermocouple detection

• Input resolution of 24 bits

• Analog throughput of up to 600 Samples/s

• Input voltage range of ±156 mV

• Four, isolated, TTL digital inputs; you can read the status of the digital input port in the analog input stream

• Four, isolated, open-collector digital outputs

Page 15

• ±500 V galvanic isolation to the computer

• Powered by USB bus; no external power supply required

• A software calibration utility is provided for calibrating the analog input subsystem

Overview

Page 16

Chapter 1

Supported Software

The following software is available for use with DT9828 modules and is shipped on the Data Acquisition OMNI CD:

• DT9828 Device Driver – The device driver allows you to use a DT9828 module with any of the supported software packages or utilities. Refer to Chapter 2 starting on page 23 for more information on loading and configuring the device driver.

• DT9828 Series Calibration Utility – The DT9828 Calibration Utility allows you to calibrate the analog input circuitry of a DT9828 module. Refer to Chapter 8 starting on

page 87 for more information on this utility.

• QuickDAQ 2013 – Allows you to acquire and analyze data from all Data Translation USB and Ethernet devices, except the DT9841 Series, DT9817, DT9835, and DT9853/54.

QuickDAQ lets you perform the following functions:

− Discover and select your devices.

− Configure all input channel settings for the attached sensor, such as the enable state,

input range, and engineering units for the sensor.

− Load/save multiple hardware configurations.

− On each device acquire data from all channels supported in the input channel list.

− Log acquired data to disk.

− Display acquired data during acquisition in either a digital display using the Channel

Display window or as a waveform using the Channel Plot window.

− Display statistics about the acquired data in the Statistics window.

− Open recorded data in Excel for further analysis.

− Customize many aspects of the acquisition, display, and recording functions to suit

your needs, including the clock frequency and the trigger settings.

You can use QuickDAQ in one of two modes: Acquisition mode, which allows you to acquire data, or File Reader mode, which allows you to view a previously recorded data file. Refer to the documentation for QuickDAQ 2013 for detailed information about the application.

• Quick DataAcq application – The Quick DataAcq application provides a quick way to get up and running using a DT9828 module. Using this application, you can verify key features of the modules, display data on the screen, and save data to disk.

• DT-Open Layers for .NET Class Library – Use this class library if you want to use Visual C# or Visual Basic for .NET to develop your own application software for a DT9828 module using Visual Studio 2003 to 2012; the class library complies with the DT-Open Layers standard.

• DataAcq SDK – Use the Data Acq SDK if you want to use Visual Studio 6.0 and Microsoft C or C++ to develop your own application software for the DT9828 module using Windows XP, Windows Vista, Windows 7, or Windows 8; the DataAcq SDK complies with the DT-Open Layers standard.

Page 17

• DAQ Adaptor for MATLAB – Data Translation’s DAQ Adaptor provides an interface between the MATLAB Data Acquisition (DAQ) subsystem from The MathWorks and Data Translation’s DT-Open Layers architecture.

• LV-Link – LV-Link allows you to access the capabilities of the DT9828 module from the LabVIEW graphical programming language.

Refer to the Data Translation web site (www.datatranslation.com) for information about selecting the right software package for your needs.

Overview

Page 18

Chapter 1

Accessories

One EP365 cable is shipped with each DT9828 module. The EP365 is a 1.83-meter, USB cable that connects the USB connector of the DT9828 module to the USB connector on the host computer. If you want to buy additional USB cables, EP365 is available as an accessory product for the DT9828 module.

Page 19

Getting Started Procedure

Install the Module

(see Chapter 2 starting on page 23)

Wire Signals

(see Chapter 3 starting on page 31)

Verify the Operation of the Module

(see Chapter 4 starting on page 41)

The flow diagram shown in Figure 2 illustrates the steps needed to get started using the DT9828 module. This diagram is repeated in each Getting Started chapter; the shaded area in the diagram shows you where you are in the procedure.

Figure 2: Getting Started Flow Diagram

Overview

Page 20

Chapter 1

Page 21

Part 1: Getting Started

Page 22

Page 23

Installing a Module

Unpacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Attaching Modules to the Computer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Configuring the Device Driver. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Page 24

Chapter 2

Install the Module

(this chapter)

Wire Signals

(see Chapter 3 starting on page 31)

Verify the Operation of the Module

(see Chapter 4 starting on page 41)

Page 25

Unpacking

Open the shipping box and verify that the following items are present:

• DT9828 module

• EP365 USB cable

• Data Acquisition OMNI CD

If an item is missing or damaged, contact Data Translation. If you are in the United States, call the Customer Service Department at (508) 481-3700, ext 1323. An application engineer will guide you through the appropriate steps for replacing missing or damaged items. If you are located outside the United States, call your local distributor, listed on Data Translation’s web site (www.datatranslation.com).

Installing a Module

Page 26

Chapter 2

Attach the USB cable (EP365) here. Plug the other end into a USB port of your host computer.

Top View of the DT9828 Module

The USB LED is green when the module is powered and blinks amber when the module is acquiring data.

Attaching Modules to the Computer

You can attach a DT9828 module to the host computer in one of two ways:

• Connect directly to a USB port of the host computer, described on this page. Use this method if one or two DT9828 modules are sufficient for your application.

• Connect to one or more self-powered USB hubs, described on page 27. Use this method if your application requires more DT9828 modules than the USB ports on the host computer.

You must install the device driver before connecting your DT9828 module(s) to the host computer.

Note: The DT9828 module is a low-power device (using less than 500 mA); therefore, it does not require an external power supply.

Connecting Directly to the USB Ports

To connect a DT9828 module directly to a USB port on your computer, do the following:

1. Attach one end of the EP365 (USB) cable, which is shipped with the DT9828 module, to

the USB port on the module.

2. Attach the other end of the EP365 cable to one of the USB ports on the host computer, as

shown in Figure 3.

The operating system automatically detects the USB device and starts the Found New Hardware wizard.

Figure 3: Attaching the Module to the Host Computer

Page 27

Installing a Module

3. For Windows Vista:

a. Click Locate and install driver software (recommended).

The popup message "Windows needs your permission to continue" appears.

b. Click Continue.

The Windows Security dialog box appears.

c. Click Install this driver software anyway.

For Windows XP:

a. Click Next and/or Finish as required in the wizard.

Once the firmware is loaded, the wizard restarts to initiate the firmware to accept commands.

b. Click Next and/or Finish again.

Note: Windows 7 and Windows 8 find the device automatically.

4. Repeat these steps to attach another DT9828 module to the host computer, if desired.

Note: You can unplug a module, and then plug it in again, if you wish, without causing

damage. This process is called hot-swapping.

Your application may take a few seconds to recognize a module once it is plugged back in.

Connecting to an Expansion Hub

Expansion hubs are powered by their own external power supply. The practical number of DT9828 modules that you can connect to a single USB port depends on the throughput you want to achieve.

Note: The bandwidth of the USB Ver. 1.1 bus is 12 Mbits/second. Each DT9828 module running at full speed (600 kHz multiplexed) requires 4800 bytes/s or 39.6 kbits/s of this bandwidth. Keep this in mind when determining how many modules to connect.

To connect multiple DT9828 modules to an expansion hub, do the following:

1. Attach one end of the USB cable to the DT9828 module and the other end of the USB cable

to an expansion hub.

2. Connect the power supply for the expansion hub to an external power supply.

3. Connect the hub to the USB port on the host computer using another USB cable.

The operating system automatically detects the USB device and starts the Found New Hardware wizard.

Page 28

Chapter 2

Self-Powered

USB Hubs

Host Computer

Power Supply

for Hub

DT9828 Module

USB Cables

USB Cable

DT9828 Module

4. For Windows Vista:

a. Click Locate and install driver software (recommended).

The popup message "Windows needs your permission to continue" appears.

b. Click Continue.

The Windows Security dialog box appears.

c. Click Install this driver software anyway.

For Windows XP:

a. Click Next and/or Finish as required in the wizard.

Once the firmware is loaded, the wizard restarts to initiate the firmware to accept commands.

b. Click Next and/or Finish again.

Note: Windows 7 and Windows 8 find the device automatically.

5. Repeat these steps until you have attached the number of hubs and modules that you

desire. Refer to Figure 4.

The operating system automatically detects the USB devices as they are installed.

Figure 4: Attaching Multiple Modules Using Expansion Hubs

Note: You can unplug a module, and then plug it in again, if you wish, without causing damage. This process is called hot-swapping.

Your application may take a few seconds to recognize a module once it is plugged back in.

Page 29

Configuring the Device Driver

Note: In Windows 7, Windows 8, and Vista, you must have administrator privileges to run the Open Layers Control Panel. When you double-click the Open Layers Control Panel icon, you may see the Program Compatibility Assistant. If you do, select Open the control panel using recommended settings. You may also see a Windows message asking you if you want to run the Open Layers Control Panel as a "legacy CPL elevated." If you get this message, click Yes.

If you do not get this message and have trouble making changes in the Open Layers Control Panel, right click the DTOLCPL.CPL file and select Run as administrator. By default, this file is installed in the following location:

Windows 7, Windows 8, and Vista (32-bit) C:\Windows\System32\Dtolcpl.cpl

Windows 7, Windows 8, and Vista (64-bit) C:\Windows\SysWOW64\Dtolcpl.cpl

Installing a Module

To configure the DT9828 Device Driver, do the following:

1. If you have not already done so, power up the host computer and all peripherals.

2. From the Windows Control Panel, double-click the Open Layers Control Panel icon.

The Data Acquisition Control Panel dialog box appears.

3. Click the DT9828 module that you want to configure.

4. If you want to rename the module, click Edit Name.

5. Enter a new name for the module, and then click OK.

Note: This name is used to identify the module in all subsequent applications.

6. When you are finished configuring the module, click Close.

7. Repeat steps 3 to 6 for the other modules that you want to configure.

8. Close the Control Panel.

Page 30

Chapter 2

Page 31

Wiring Signals

General Wiring Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Connecting Thermocouple Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Connecting Voltage Input Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Connecting Current Loop Inputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Connecting Digital Input Signals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Connecting Digital Output Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Page 32

Chapter 3

Install the Module

(see Chapter 2 starting on page 23)

Wire Signals

(this chapter)

Verify the Operation of the Module

(see Chapter 4 starting on page 41)

Note: If you are using thermocouples with the DT9828 module, it is recommend that you run the DT9828 Series Calibration Utility prior to using the module. Refer to Chapter 8 starting on page 87 for instructions.

Page 33

General Wiring Recommendations

Keep the following recommendations in mind when wiring signals to a DT9828 module:

• Separate power and signal lines by using physically different wiring paths or conduits.

• To avoid noise, do not locate the instrument and cabling next to sources that produce high electromagnetic fields, such as large electric motors, power lines, solenoids, and electric arcs, unless the signals are enclosed in a mumetal shield.

• Locate the DT9828 module as far away as possible from sources of high or low temperatures or strong air currents, such as fans.

• Prevent electrostatic discharge to the I/O while the instrument is operational.

• When wiring thermocouples, use a wire insulation strip length of 0.197 inches (5 mm).

• Use 16 AWG to 26 AWG shielded wire for maximum rejection of electrical interference.

Note: The DT9828 module requires a warm-up time of 10 minutes for the analog circuitry to stabilize.

Wiring Signals

Page 34

Chapter 3

Side View

Analog Input Screw Terminal Block (TB1)

Insert wires through the side and

screw from the top.

Connecting Thermocouple Inputs

DT9828 modules support up to eight, differential thermocouple channels. You connect thermocouple signals to the Analog Input screw terminal block (TB1) of the DT9828 module, shown in Figure 5.

Figure 5: Analog Input Screw Terminal Block (TB1)

Page 35

Figure 6 shows how to connect a thermocouple input to a DT9828 module.

Thermocouple

Input

One cold-junction compensation (CJC) circuit is provided for all thermocouple input channels. The software reads the value of the CJC input and applies it to the value of the thermocouple input to correct for errors based on the specified thermocouple type.

The output of the channel goes to positive, full-scale if an open circuit is detected at the input.

DT9828

Analog Input Terminal Block

TB1

High

Low

. . .

Figure 6: Connecting Thermocouple Inputs (Shown for Analog Input Channel 0)

Wiring Signals

Page 36

Chapter 3

Floating

Signal

Source

1 2

CH 0+

CH 0–

. . .

DT9828

Analog Input Terminal Block

TB1

Grounded

Signal

Source

CH 0+

CH 0–

Signal Source

Ground V

. . .

DT9828

Analog Input Terminal Block

TB1

Connecting Voltage Input Signals

DT9828 modules support up to eight, differential voltage input channels. You connect voltage input signals to the Analog Input screw terminal block (TB1) of the DT9828 module, shown in

Figure 5 on page 34.

Figure 7 illustrates how to connect a floating signal source to a DT9828 module. (A floating

signal source is a voltage source that has no connection with earth ground.)

Figure 7: Connecting Differential Voltage Inputs (Shown for Analog Input Channel 0)

Figure 8 illustrates how to connect a grounded (nonfloating) signal source to a DT9828

module.

Figure 8: Connecting Differential Voltage Inputs from a Grounded Signal Source

(Shown for Analog Input Channel 0)

Page 37

Connecting Current Loop Inputs

CH 0+

CH 0–

4 to 20 mA

User-installed resistor

The user-installed resistor connects the high side of the channel to the low side of the corresponding channel, thereby acting as a shunt.

If, for example, you add a 1

Ω resistor, and then

connect a 4 to 20 mA current loop input to channel 0, the input range is converted to 4 mV to 20 mV.

Be sure to choose a resistor such that the voltage developed across it remains within the ±156 mV input range of the DT9828.

. . .

DT9828

Analog Input Terminal Block

TB1

You connect current loop inputs to the Analog Input screw terminal block (TB1) of the DT9828 module, shown in Figure 5 on page 34.

Figure 9 shows how to connect a current loop input to a DT9828 module.

Wiring Signals

Figure 9: Connecting Current Inputs (Shown for Analog Input Channel 0)

Page 38

Chapter 3

Side View

Digital I/O Screw Terminal Block (TB2)

Insert wires through the side and

screw from the top.

Connecting Digital Input Signals

DT9828 modules support up to four digital input lines. You connect digital input signals to the Digital I/O screw terminal (TB2) of the DT9828 module, shown in Figure 10.

Figure 10: Digital I/O Screw Terminal Block (TB2)

Page 39

Wiring Signals

Digital Input 0

Digital Input 1

Digital In Return

TTL Inputs

DT9828

Digital I/O Terminal Block

TB2

Figure 11 shows how to connect digital input signals (lines 0 and 1, in this case) to a DT9828

module.

Figure 11: Connecting Digital Inputs (Shown for Digital Input Lines 0 and 1)

Page 40

Chapter 3

Digital Out Return

Digital Out 0

Controlled by

Software

100 kΩ

+5 V

External

Supply

–

External Supply

External Supply Return

DT9828

Digital I/O Terminal Block

TB2

External

Logic Gate

Optocoupler

Connecting Digital Output Signals

The DT9828 provides four open-collector digital outputs and a common return that are isolated from the analog input circuitry, USB ground, and digital input ground. The open collector outputs have a drive capability of 2 mA maximum and can control circuitry that is powered from an external supply.

Digital I/O terminal block TB2, shown in Figure 10 on page 38 provides screw terminals for connecting an external supply (in the 3.3 VDC to 30 VDC range) and an external supply return.

Each open collector output has a weak pull-up resistor of 100 kΩ to the External Supply terminal of the screw terminal block TB2. Connecting a 3.3 V to 5 V supply provides outputs that are capable of driving TTL-level logic.

Figure 12 shows an example of connecting an open-collector digital output on the DT9828

module to an external supply and logic gate.

Figure 12: An Example of Connecting An Open-Collector Digital Output to an External Supply and

Logic Gate (Shown for Digital Output Line 0)

Page 41

Verifying the Operation of a Module

Selecting the Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Thermocouple Measurement Example. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Page 42

Chapter 4

Install the Module

(see Chapter 2 starting on page 23)

Wire Signals

(see Chapter 3 starting on page 31)

Verify the Operation of the Module

(this chapter)

QuickDAQ 2013 allows you to acquire and analyze data from all Data Translation USB and Ethernet devices, except the DT9841 Series, DT9817, DT9835, and DT9853/54. This chapter describes how to verify the operation of a DT9828 module using QuickDAQ.

Page 43

Selecting the Device

To get started with your DT9828 module and the QuickDAQ application, follow these steps:

1. Connect the DT9828 module to the USB port of your computer, and connect your

thermocouples or voltage inputs to the module.

2. Start the QuickDAQ application.

The Device Selection window appears.

Verifying the Operation of a Module

3. For the Device Family selection, select OpenLayersDevices.

By default, the application "discovers" all devices that are available for the specified device family and displays the module name for the USB devices in the drop-down list. If you want to refresh this list to determine if other devices are available, click Refresh.

4. Select the module name for the module that you want to use from the list of Available

Devices, and click Add.

Information about the device, including the model number, serial number, firmware version, driver version, and scanning status is displayed.

Page 44

Chapter 4

5. (Optional) If you want to remove a device from list of selected devices, click the Row

Selector button for the device, and then click Remove.

6. Once you have added all the devices that you want to use with the application, click OK.

The latest state is saved and used when the application is next run, and the interface of the QuickDAQ application is displayed.

Page 45

Thermocouple Measurement Example

The following steps describe how to use the QuickDAQ application to measure temperature from thermocouple inputs.

This example uses a type J thermocouple connected to analog input channel 0 and a type T thermocouple connected to analog input channel 1 of a DT9828 module.

Configure the Channels

Configure the channels as follows:

1. Configure each analog input channel by clicking the Configuration menu, and clicking

Input Channel Configuration, or by clicking the Input Channel Configuration toolbar

button ( ).

2. Enable analog input channels 0 and 1 by clicking the checkbox under the Enable column.

Verifying the Operation of a Module

3. Under the Channel Name column, enter a meaningful name for the channel.

For this example, enter Tem p 1 for analog input channel 0 and Te m p 2 for analog input channel 1.

Page 46

Chapter 4

4. Under the Sensor column, select the sensor type for the channel.

For this example, set the sensor type for analog input channel 0 to Type J and the sensor type for analog input channel 1 to Type T.

5. Under the Engineering Units column, Deg C is selected by default. If you want to change

this setting, change the temperature units under the Acquisition Config - Acquisition tab.

In this example, Deg C is used.

6. If you know the offset for your calibrated thermocouple, enter it under the EU Offset

column.

For this example, leave 0 as the EU offset for the thermocouple.

7. Leave the test point values for each channel unchanged.

8. Click Close to close the Channel Configuration dialog box.

Configure the Parameters of the Acquisition Config Window

For this example, set the Acquisition Config parameters as follows:

1. Click the Recording tab.

2. For Filename, enter a meaningful name for the data file.

In this example, LogData.hpf is used.

Page 47

Verifying the Operation of a Module

3. Leave the Enable Continuous Acquisition checkbox unchecked.

4. For Acquisition Duration, select 10 seconds as the time to acquire the measurement data.

The amount of available disk space is shown; in addition, the number of scans in the Acquisition Info area is updated based on the acquisition duration that is selected.

5. For X Axis Span, leave 10 seconds as the span for the x-axis.

6. Click the Acquisition tab.

7. For this example, ensure that the following default settings are used:

− Per Channel Sampling Frequency: 300 Hz

− Trigger Source: Software

− Temperature Unit: Celsius

− Filter type: Moving Average

8. If desired, hide the Acquisition Config window by clicking the Auto-Hide pin ( ) in

the top, right corner of the window.

Page 48

Chapter 4

Configure the Appearance of the Channel Plot Window

Configure the appearance of the Channel Plot window as follows:

1. In the Plot and Data Config window, set up the following parameters:

a. Ensure that the Visible Plot column is checked for both enabled channels.

b. Leave the Show Cursor column unchecked for all three enabled channels.

c. Under Plot Column, use the default plot column setting of 1 for both enabled

channels.

d. Under the Signal Group column, select A for both thermocouple channels.

e. Under the Color column, assign a unique color to each trace.

2. In the display area, click the tab for the Channel Plot window.

3. Click the Show Legend control (

4. Change the text for the label on the x-axis, by doing the following:

a. Right-click on the label.

b. Select Edit Label.

c. Enter the following text: Thermocouple Channels.

The Channel Plot window should appear as follows:

) on the toolbar.

Page 49

Verifying the Operation of a Module

Page 50

Chapter 4

Configure the Appearance of the Channel Display Window

Configure the appearance of the Channel Display window as follows:

1. Ensure that the Visible Display column in the Plot and Data Config window is checked

for both enabled channels.

2. Click the Channel Display - Control tab, and select the Hide Unused Channels checkbox

so that only analog input channels 0 and 1 are displayed.

Page 51

3. For the Data Reduction Method, select Max so that the maximum value of the most recent

buffer is displayed for each channel.

4. Leave the default values for the remaining parameters:

− Precision = 2

− Columns = 8

− Display Update rate = middle of slider bar

Configure the Appearance of the Statistics Window

Configure the appearance of the Statistics window as follows:

1. Ensure that the Visible Statistics column in the Plot and Data Config window is checked

for both channels:

Verifying the Operation of a Module

2. If desired, hide the Plot and Data Config window by clicking the Auto-Hide pin ( ) in

the top, right corner of the window.

Position the Windows

If you want see the data that is displayed in the Channel Display, Channel Plot, and Statistics windows at once, you need to move the windows to different locations in the display area.

In the following example, the Channel Display window is located at the top of the display area, the Channel Plot window is located in the middle of the display area, and the Statistics window is located at the bottom of the display area:

Page 52

Chapter 4

Perform the following steps to position the Channel Display window at the top of the display area, the Channel Plot window in the middle of the display area, and the Statistics window at the bottom of the display area:

1. Click the tab for the Statistics window, drag the window toward the middle of the display

area, move the mouse over the guide on the bottom of the guide diamond, and then release the mouse button.

The Statistics window is now placed at the bottom of the display area.

2. Click the tab for the Channel Plot window, drag the window toward the middle of the

display area, move the mouse over the guide on the bottom of the guide diamond, and then release the mouse button.

The Channel Plot window is now placed in the middle of the display area, revealing the Channel Display window at the top of the display area.

3. Resize each window, as desired.

Page 53

Start the Measurement

Once you have configured the channels and the display area, start acquisition and log data to disk by clicking the Record toolbar button ( ).

Results similar to the following are displayed in the display area.

Verifying the Operation of a Module

If desired, you can view the data in Excel by clicking the Open Current Data in Excel toolbar button ( ).

Page 54

Chapter 4

Page 55

Part 2: Using Your Module

Page 56

Page 57

Principles of Operation

Analog Input Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Digital I/O Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Page 58

Chapter 5

Digital Out

(Opto Coupled)

x 4

MUX

8:1 Differential

24-Bit

Delta-Sigma

ADC

Controls

MUX

Controls

Bus

Interface

and

Control

Registers

USB

High Speed

Interface

EEPROM

FPGA

Digital In

(Opto Coupled)

x 4

12 Pos

Term Block

16 Pos

Term Block

Status LED

DC/DC

CJ Sensor

FPGA

5 V DC

USB

Isolated Power

8 Thermocouple

or Differential

Voltage Inputs

Digital

Outputs

4 Digital Inputs

+/- 500 V

Isolation Barrier

Break Detection

on each channel

Digital Output Supply

Digital Output Return

USB 2.0

Figure 13 shows a block diagram of the DT9828 module.

Figure 13: Block Diagram of the DT9828 Module

Page 59

Analog Input Features

This section describes the features of the analog input (A/D) subsystem, including the following:

• Analog input channels, described next

• Cold junction compensation, described on page 61

• Open thermocouple detection, described on page 61

• Input ranges and gains, described on page 61

• Input resolution, described on page 62

• A/D sample clock sources, described on page 62

• Triggers, described on page 63

• Analog input conversion modes, described on page 63

•Filtering, described on page 65

• Data format, described on page 65

• Error conditions, described on page 66

Principles of Operation

Analog Input Channels

The DT9828 module supports eight differential analog input channels. You can use the analog input channels for thermocouple or voltage measurements. You wire these inputs to the screw terminals on the module. Refer to Chapter 3 starting on page 31 for wiring information.

You can attach one of the following thermocouple types to each analog input channel: J, K, T, B, E, N, R, and/or S. If desired, you can attach a voltage input to each analog input channel instead.

You can specify the thermocouple types for channels using software.

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Tabl e 1 lists the supported measurement range for each thermocouple type.

Table 1: Supported Measurement Range for Each Thermocouple Type

Supported Measurement Range

Thermocouple

Typ e

J –210° C (–346° F) 1200° C (2192° F)

K –200° C (–328° F) 1372° C (2502° F)

T –200° C (–328° F) 400° C (752° F)

B 250° C (482° F) 1820° C (3308° F)

E –200° C (–328° F) 1000° C (1832° F)

N –200° C (–328° F) 1300° C (2372° F)

R –50° C (–58° F) 1768° C (3214° F)

S –50° C (–58° F) 1768° C (3214° F)

Minimum Maximum

Refer to page 95 for the thermocouple accuracy of thermocouple channels over the dynamic range of the instrument.

The DT9828 module can acquire data from a single analog input channel or from a group of analog input channels. Analog input channels are numbered 0 to 7. The following subsections describe how to specify the channels.

Specifying a Single Channel

The simplest way to acquire data from a single analog input channel is to specify the channel for a single-value analog input operation using software; refer to page 63 for more information on single-value operations.

You can also specify a single channel using the analog input channel list, described in the next section.

Specifying One or More Channels

You can read data from one or more analog input channels using an analog input channel list. You can group the channels in the list sequentially (starting either with 0 or with any other analog input channel) or randomly. You can also specify a single channel or the same channel more than once in the list.

Using software, specify the analog input channels in the order you want to sample them. You can enter up to 1024 entries in the channel list. For the DT9828, channels 0 to 7 correspond to the analog input channels and channel 8 corresponds to the digital input port.

Reading the digital input port (digital lines 0 to 3) using the analog input channel list is particularly useful when you want to correlate the timing of analog and digital events.

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The channels are read in order from the first entry to the last entry in the channel list. Refer to

page 63 for more information on the supported conversion modes.

Cold Junction Compensation

The conversion time for the CJC circuitry is 240 ms, typical. The software takes care of correlating the CJC measurements with the analog input measurements.

Note: When using the DT-Open Layers for .NET Class Library, the software provides the option of returning CJC values in the data stream. This option is seldom used, but is provided if you want to implement your own temperature conversion algorithms in software when using continuous operations. Refer to page 65 for more information on this feature.

Principles of Operation

Open Thermocouple Detection

A 10 MΩ pull-up resistor is provided on the high side input of each differential thermocouple channel for open thermocouple detection. When an open thermocouple is detected, a positive, full-scale input voltage is returned.

The software returns the value SENSOR_IS_OPEN (99999 decimal) for any channel that was configured for a thermocouple input and has either an open thermocouple or no thermocouple connected to it.

Input Ranges and Gains

The DT9828 module supports an input range of ±156 mV. In software, specify a gain of 1.

If a voltage is measured on the input that is outside of the range for the selected thermocouple type, the channel may be configured for the wrong type of thermocouple or something other than a thermocouple may be connected to the channel.

In addition, if the input voltage is less than the legal voltage range for the selected thermocouple type, the software returns the value TEMP_OUT_OF_RANGE_LOW (–88888 decimal). If the input voltage is greater than the legal voltage range for the selected thermocouple type, the software returns the value TEMP_OUT_OF_RANGE_HIGH (88888 decimal).

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Note: If you are continuously measuring from a properly configured thermocouple input channel and the thermocouple opens or becomes disconnected, the open thermocouple pull-up circuit causes the input voltage to rise to approximately 1.5 V over a few seconds.

In this case, the temperature value rises very quickly, and you will receive the TEMP_OUT_OF_RANGE_HIGH (88888 decimal) value followed by the OPEN_SENSOR (99999 decimal) value.

Input Resolution

The input resolution of the analog input subsystem on the DT9828 module is 24 bits.

A/D Sample Clock

The DT9828 module uses an internal A/D sample clock with a time base of 4.9152 MHz to pace analog input operations in continuous mode. This clock paces the acquisition of each channel in the channel list.

The maximum total throughput is 600 Samples/s. The minimum total throughput rate is

0.5865 Samples/s.

The data rate per channel is computed as follows:

Data Rate per Channel = Throughput Rate/Number of Channels

For example, to sample all eight channels at the maximum rate, the data rate per channel is 600/8, or 75 Samples/s.

Using software, specify the channels that you want to sample in the channel list, and then set the desired sampling frequency. The software sets the sampling frequency to the closest possible value. You can use software to return the actual frequency that is used.

Note: In QuickDAQ, you specify the per channel sampling frequency. In the DT-Open Layers Class Library and the Data Acq SDK, you specify the aggregate (total) sampling frequency. See Tabl e 2 for examples of the per channel sampling frequency based on the number of channels.

According to sampling theory (Nyquist Theorem), specify a frequency that is at least twice as fast as the input’s highest frequency component. For example, to accurately sample a 20 Hz signal, specify a sampling frequency of at least 40 Hz. Doing so avoids an error condition called aliasing, in which high frequency input components erroneously appear as lower frequencies after sampling.

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Table 2: Example of Per Channel Sampling Frequency

Principles of Operation

Number of

Input

Channels

1 600.00 300.00 200.00 120.00 100.00 60.00 40.00 10.00 6.00 1.00

2 300.00 150.00 100.00 60.00 50.00 30.00 20.00 5.00 3.00 0.50

3 200.00 100.00 66.67 40.00 33.33 20.00 13.33 3.33 2.00 0.33

4 150.00 75.00 50.00 30.00 25.00 15.00 10.00 2.50 1.50 0.25

5 120.00 60.00 40.00 24.00 20.00 12.00 8.00 2.00 1.20 0.20

6 100.00 50.00 33.33 20.00 16.67 10.00 6.67 1.67 1.00 0.17

7 85.71 42.86 28.57 17.14 14.29 8.57 5.71 1.43 0.86 0.14

8 75.00 37.50 25.00 15.00 12.50 7.50 5.00 1.25 0.75 0.13

600 300 200 120 100 60 40 10 6 1

Total Throughput (Hz)

Input Trigger

The DT9828 modules support a software trigger event to start the analog input operation. A software trigger occurs when you start the analog input operation (the computer issues a write to the module to begin conversions). Using software, specify the trigger source as a software trigger.

Analog Input Conversion Modes

DT9828 modules support single-value and continuous scan conversion modes. This section describes each of these conversion modes.

Single-Value Operations

Single-value operations are simpler to use than continuous operations. Using software, you specify the analog input channel that you want to use. For the DT9828, specify channel 0, 1, 2, 3, 4, 5, 6, or 7. The module acquires the data from the specified channel and returns the data immediately.

For single-value operations, you cannot specify a clock frequency, trigger source, scan mode, or buffer. Single-value operations stop automatically when finished; you cannot stop a single-value operation.

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Chan 1

Input

Sample

Clock

Chan 2 Chan 0 Chan 1

Software Trigger occurs

Data is acquired continuously

Chan 0 Chan 2

Continuous Scan Mode

Continuous scan mode takes full advantage of the capabilities of the DT9828 module. You can specify a channel list, sampling frequency, start trigger, and buffer using software.

You can enter up to 1024 entries in the channel list. For the DT9828, channels 0 to 7 correspond to the analog input channels and channel 8 corresponds to the digital input port. Using software, specify the channels you want to sample.

When a software trigger (software command) is detected, the module cycles through the channel list, acquiring and converting the value for each entry in the list (this process is defined as the scan). The sampled data is placed in the allocated buffer(s). When the module gets to the end of the channel list, it wraps to the start of the channel list and repeats the process continuously until you stop the operation.

Using software, you can stop a scan by performing either an orderly stop or an abrupt stop. In an orderly stop, the module finishes acquiring the current buffer, stops all subsequent acquisition, and transfers the acquired data to host memory; any subsequent triggers are ignored. In an abrupt stop, the module stops acquiring samples immediately; the current buffer is not completely filled, it is returned to the application only partially filled, and any subsequent triggers are ignored.

The conversion rate is determined by the sampling frequency of the input sample clock; refer to page 62 for more information about the input sample clock.

To select continuous scan mode, use software to specify the following parameters:

• Specify the data flow as Continuous

• Specify the clock source as internal and specify the sampling frequency (refer to page 62)

• Specify the trigger as a software trigger (refer to page 63)

Figure 14 illustrates continuous scan mode with a channel list of three entries: channel 0

through channel 2. In this example, analog input data is acquired when a software trigger is detected.

Figure 14: Continuous Scan Mode on the DT9828 Module

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Note: The USB LED, shown in Figure 3 on page 26, blinks amber while the module is acquiring data.

Filtering

The DT9828 module multiplexes all enabled channels to a single 24-bit Delta-Sigma analog-to-digital converter (ADC). The overall throughput rate is programmable to up to 600 Samples/s. The throughput rate determines the ADC data rate, internal filter response, and noise. The Delta-Sigma ADC noise is inherently low at all sample rates, but sampling at lower rates yields lower noise. Additional noise filtering is implemented in software by a moving average filter, which may be enabled or disabled in software.

The software filtering options are described as follows:

• Moving average – (The default filter setting.) This filter type removes unwanted noise

Principles of Operation

from your measurements and provides a compromise of filter functionality and response time. This filter can be used in any application.

This low-pass filter takes the previous 16 samples, adds them together, and divides by 16.

• None – No filter (raw data). Use this option when you want to acquire fast thermocouple response times. The response time is determined by the ADC data rate. Higher throughput rates (data rates) yield faster response times, but the increased bandwidth also results in higher noise.

Data Format

If you specify a thermocouple type of None for a thermocouple input channel, a voltage measurement is selected and the instrument returns a voltage value. For all other thermocouple types, a temperature value, in degrees C, or one of the error constants, described on page 61, is returned.

In normal operation, one, 32-bit floating-point value is returned for each enabled channel. If you enable the capability of returning CJC data in the data stream, described on page 61, two floating-point values are returned in the data stream for each enabled analog input channel. The first value in the pair represents the temperature (or voltage) of the channel; the second value in the pair represents the CJC temperature (in degrees C) for that channel.

If the digital input port is in the channel list, that 4-bit value (value 0 to 15) is returned as float.

Note: The Input FIFO stores up to 1024 samples.

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Error Conditions

The DT9828 module reports overrun errors by sending an overrun event to the application program. If this error condition occurs, the instrument stops acquiring and transferring data to the host computer. To avoid this error, try one or more of the following:

• Reduce the sample rate

• Close any other applications that are running

• Run the program on a faster computer

Additionally, the following constants may be reported to the host:

• 99999.0 – SENSOR_IS_OPEN, described on page 61

• 88888.0 – TEMP_OUT_OF_RANGE_HIGH, described on page 61

• –88888.0 – TEMP_OUT_OF_RANGE_LOW, described on page 61

An additional error will be reported if a ESD spike causes an analog input channel to stop working. If the instrument is scanning when this occurs, scanning will stop and an error will be reported. To resume scanning, you must restart the scan. If the channel is functional, scanning will resume. If the channel is not functional, scanning will not resume and the error will be reported once again; contact Customer Service, as described on page 91, to return the module to the factory.

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Digital I/O Features

The DT9828 module provides four digital inputs and 4 digital outputs that you can use to control external equipment.

This section describes the following digital I/O features of the DT9828 module:

• Digital input lines, described on this page

• Digital output lines, described on this page

• Resolution, described on page 68

• Operation modes, described on page 68

Digital Input Lines

The DT9828 module features four, isolated digital input lines. The digital inputs have a common ground (Digital Input Return) that is isolated from USB, analog, and digital output grounds.

The response time of the digital inputs is less than 100 μs.

Principles of Operation

Using software, specify the digital input line that you want to read in single-value digital I/O operation. Refer to page 68 for more information about single-value operations.

A digital line is high if its value is 1; a digital line is low if its value is 0.

Digital Output Lines

The DT9828 module features four, isolated, open-collector digital output lines. The digital outputs have a common return that is isolated from the USB ground, analog input ground, and digital input ground.

Each digital output has a 100 kΩ pull-up resistor to the External Supply terminal on the digital I/O terminal block. You can connect an external supply in the 3.3 VDC to 30 VDC range to this terminal, and then connect the external supply return to the External Supply Return terminal on the digital I/O terminal block.

Using software, you can specify the digital I/O line that you want to set in a single-value digital I/O operation. Refer to page 68 for more information about single-value operations.

Setting a digital output line to 0 turns on the corresponding open collector output and pulls the output low. Setting a digital output line to 1 turns off the corresponding open collector; the output is pulled up to the external supply level.

On power up or reset of a DT9828 module, the digital output lines are set to 1 (open collectors are off; the outputs are pulled up to the external supply level).

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Resolution

The digital input and digital output subsystems on the DT9828 module have a resolution of 4 bits.

Operation Modes

DT9828 modules support the following digital I/O operation modes:

• Single-value operations are the simplest to use but offer the least flexibility and efficiency. You use software to specify the digital I/O port and a gain of 1 (the gain is ignored). Data is then read from or written to all the digital I/O lines. For a single-value operation, you cannot specify a clock frequency or trigger source.

Single-value operations stop automatically when finished; you cannot stop a single-value operation.

• Continuous digital input takes full advantage of the capabilities of the DT9828 module. You can specify a sampling frequency, conversion mode, trigger source, and buffer for the operation.

For the DT9828, enter the digital input port as channel 8 in the analog input channel list. Refer to page 60 for more information on specifying channels.

The A/D sample clock paces the reading of the digital input port (as well as the acquisition of the analog input channels); refer to page 62 for more information on the A/D sample clock.

Note: If the digital input port is in the channel list, that 4-bit value (value 0 to 15) is returned as float.

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Supported Device Driver Capabilities