Data Translation DT9812, DT9814 Instruction Manual

Download

UM-20769-E

DT9812, DT9813, and DT9814 User’s Manual

Fifth Edition March, 2006

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 DataAcq SDK

, DT-LV LinkTM, and DTx-EZTM

are trademarks of Data Translation, Inc.

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

Radio and Television Interference

This equipment has been tested and found to comply with CISPR EN55022 Class A, and EN50082-1 (CE) 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.

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.

Table of Contents

About this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Intended Audience. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

How this Manual is Organized . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Conventions Used in this Manual . . . . . . . . . . . . . . . . . . . . . . . . . 13

Related Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Where To Get Help. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Chapter 1: Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Key Hardware Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Channel-Gain List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Counter/Timer Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Supported Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

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

Part 1: Getting Started . . . . . . . . . . . . . . . . . . . . 21

Chapter 2: Preparing to Use a Module. . . . . . . . . . . . . . . . . 23

Unpacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Checking the System Requirements . . . . . . . . . . . . . . . . . . . . . . . 25

Installing the Software. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Chapter 3: Setting Up and Installing

the Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Attaching Modules to the Computer . . . . . . . . . . . . . . . . . . . . . . 31

Connecting Directly to the USB Ports . . . . . . . . . . . . . . . . . . 31

Connecting to an Expansion Hub . . . . . . . . . . . . . . . . . . . . . 33

Changing the Name of a Module (Optional) . . . . . . . . . . . . . . . . 35

Chapter 4: Wiring Signals to the Module. . . . . . . . . . . . . . . 37

Contents

Preparing to Wire Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Wiring Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Wiring Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Connecting Analog Input Signals . . . . . . . . . . . . . . . . . . . . . . . . . 43

Connecting Analog Output Signals . . . . . . . . . . . . . . . . . . . . . . . 44

Connecting Digital I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Connecting Counter/Timer Signals . . . . . . . . . . . . . . . . . . . . . . . 47

Event Counting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Frequency Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Edge-to-Edge Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Rate Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Chapter 5: Verifying the Operation

of a Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Using the Oscilloscope Function . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Using the Chart Recorder Function . . . . . . . . . . . . . . . . . . . . . . . 58

Using the Voltmeter Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Using the File Viewer Function . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Using the Waveform Generator Function . . . . . . . . . . . . . . . . . . 61

Using the Digital Input Function . . . . . . . . . . . . . . . . . . . . . . . . . 62

Using the Digital Output Function . . . . . . . . . . . . . . . . . . . . . . . . 63

Using the Counter Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Using the Rate Generator Function . . . . . . . . . . . . . . . . . . . . . . . 65

Part 2: Using Your Module . . . . . . . . . . . . . . . . . 67

Chapter 6: Principles of Operation . . . . . . . . . . . . . . . . . . . 69

Analog Input Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Input Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Analog Input Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Specifying a Single Analog Input Channel . . . . . . . . . 74

Specifying One or More Analog Input Channels . . . . 74

Input Ranges and Gains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Specifying the Gain for a Single Channel . . . . . . . . . . . 76

Specifying the Gain for One or More Channels . . . . . . 76

Input Sample Clock Sources . . . . . . . . . . . . . . . . . . . . . . . . . . 77

Analog Input Conversion Modes . . . . . . . . . . . . . . . . . . . . . 78

Single-Value Operations . . . . . . . . . . . . . . . . . . . . . . . . . . 78

Continuous Scan Mode . . . . . . . . . . . . . . . . . . . . . . . . . . 78

Input Triggers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

Data Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

Converting a Binary Code to a Voltage . . . . . . . . . . . . 81

Converting a Twos Complement Code to a Voltage . . 82

Error Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

Analog Output Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

Output Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

Analog Output Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

Specifying a Single Analog Output Channel . . . . . . . . 83

Specifying Analog Output Channels . . . . . . . . . . . . . . 84

Output Ranges and Gains . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

Output Trigger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

Output Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

Output Conversion Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

Single-Value Operations . . . . . . . . . . . . . . . . . . . . . . . . . . 86

Continuous Output Mode . . . . . . . . . . . . . . . . . . . . . . . 86

Data Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

Converting a Voltage into a Binary Code . . . . . . . . . . . 88

Converting a Voltage to a Twos Complement Code . . 89

Contents

Error Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

Digital I/O Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

Digital I/O Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

Operation Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

Counter/Timer Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

C/T Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

C/T Clock Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

Gate Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

Pulse Duty Cycles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

Counter/Timer Operation Modes . . . . . . . . . . . . . . . . . . . . . 94

Event Counting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94

Frequency Measurement . . . . . . . . . . . . . . . . . . . . . . . . . 95

Edge-to-Edge Measurement . . . . . . . . . . . . . . . . . . . . . . 96

Rate Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

Chapter 7: Supported Device Driver Capabilities. . . . . . . . 99

Data Flow. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

Buffering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

DMA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

Triggered Scan Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104

Synchronous Digital I/O. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107

Triggers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

Clocks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109

Counter/Timers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

Miscellaneous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

Chapter 8: Programming Flowcharts. . . . . . . . . . . . . . . . . 113

Single-Value Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

Continuous A/D Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

Continuous D/A Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

Event Counting Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

Frequency Measurement Operations . . . . . . . . . . . . . . . . . . . . . 123

Edge-to-Edge Measurement Operations . . . . . . . . . . . . . . . . . . 125

Pulse Output Operations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

Simultaneous Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129

Chapter 9: Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . 143

General Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144

Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

If Your Module Needs Factory Service . . . . . . . . . . . . . . . . . . . . 149

Chapter 10: Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151

Using the DT9812 Series Calibration Utility . . . . . . . . . . . . . . . 153

Calibrating the Analog Input Subsystem . . . . . . . . . . . . . . . . . . 154

Connecting a Precision Voltage Source . . . . . . . . . . . . . . . . 154

Using the Auto-Calibration Procedure . . . . . . . . . . . . . . . . 154

Using the Manual Calibration Procedure . . . . . . . . . . . . . . 155

Calibrating the Analog Output Subsystem . . . . . . . . . . . . . . . . 156

Contents

Appendix A: Specifications . . . . . . . . . . . . . . . . . . . . . . . . 157

Appendix B: Screw Terminal Assignments . . . . . . . . . . . 169

Appendix C: Reading from or Writing to the Digital Registers

173

Contents

The first part of this manual describes how to install and set up your DT9812-2.5V, DT9812-10V, DT9813-10V, and DT9814-10V modules and software, and verify that your modules are working properly.

The second part of this manual describes the features of the DT9812-2.5V, DT9812-10V, DT9813-10V, and DT9814-10V modules, the capabilities of the device driver, and how to program the modules using the DT-Open Layers™ software. It also provides troubleshooting information.

Note: If the information in this manual applies to both versions of the DT9812 module, this manual uses the product name "DT9812 module." If the information applies to a specific module, this manual uses the specific product name.

Intended Audience

About this Manual

This document is intended for engineers, scientists, technicians, or others responsible for using and/or programming the modules for data acquisition operations in the Microsoft® Windows® 2000 or Windows XP operating system. It is assumed that you have some familiarity with data acquisition principles and that you understand your application.

About this Manual

How this Manual is Organized

This manual is organized as follows:

• Chapter 1, “Overview,” describes the major features of the DT9812-2.5V, DT9812-10V, DT9813-10V, and DT9814-10V modules, as well as the supported software and accessories for the modules.

• Chapter 2, “Preparing to Use a Module,” describes how to unpack the module, check the system requirements, and install the software.

• Chapter 3, “Setting Up and Installing the Module,” describes how to install the module and how to configure the device driver.

• Chapter 4, “Wiring Signals to the Module,” describes how to wire signals to the module.

• Chapter 5, “Verifying the Operation of a Module,” describes how to verify the operation of the module with the GO! application.

• Chapter 6, “Principles of Operation,” describes all of the features of the modules and how to use them in your application.

• Chapter 7, “Supported Device Driver Capabilities,” lists the data acquisition subsystems and the associated features accessible using the device driver.

• Chapter 8, “Programming Flowcharts,” describes the processes you must follow to program the subsystems of a module using DT-Open Layers-compliant software.

• Chapter 9, “Troubleshooting,” provides information that you can use to resolve problems with a module and device driver, should they occur.

• Chapter 10, “Calibration,” describes how to calibrate the analog I/O circuitry of the 10V modules.

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

• Appendix B, “Screw Terminal Assignments,” shows the screw terminal assignments of the modules.

• Appendix C, “Reading from or Writing to the Digital Registers,” describes register-level functions that you can use to program the digital I/O lines of your module.

• An index completes this manual.

Conventions Used in 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.

About this Manual

Related Information

Refer to the following documents for more information on using the DT9812, DT9813, and DT9814 modules:

• 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).

• DT Measure Foundry Getting Started Manual (UM-19298) and online help. These documents describe how to use DT Measure Foundry™ to build drag-and-drop test and measurement applications for Data Translation® data acquisition devices without programming.

• DataAcq SDK User’s Manual (UM-18326). For programmers who are developing their own application programs using the

About this Manual

Microsoft C compiler, this manual describes how to use the DT-Open Layers DataAcq SDK™ to access the capabilities of Data Translation data acquisition devices.

• DTx-EZ Getting Started Manual (UM-15428). This manual describes how to use the ActiveX controls provided in DTx-EZ™ to access the capabilities of Data Translation data acquisition devices in Microsoft Visual Basic® or Visual C++®.

• DT-LV Link Getting Started Manual (UM-15790). This manual describes how to use DT-LV Link™ with the LabVIEW™ graphical programming language to access the capabilities of Data Translation data 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.

• Microsoft Windows 2000 or Windows XP documentation.

• USB web site (http://www.usb.org).

Where To Get Help

Should you run into problems installing or using a module, the Data Translation Technical Support Department is available to provide technical assistance. Refer to Chapter 9 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).

Overview

Key Hardware Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Supported Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

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

Chapter 1

Key Hardware Features

The DT9812-2.5V, DT9812-10V, DT9813-10V, and DT9814-10V modules are part of the ECONseries of economy, multifunction mini-instruments. Tabl e 1 lists the key features of each module.

Table 1: Key Features of the DT9812, DT9813, and DT9814

Modules

Analog

Module

DT9812-2.5V 8 SE 2 0 to

DT9812-10V 8 SE 2

DT9813-10V

DT9814-10V

Inputs

16 SE

24 SE

Analog

Outputs

I/O

Range

2.44 V

±10 V

Sample

Rate

50 kS/s 8 in/ 8 out

50 kS/s 4 in/ 4 out

50 kS/s --

All modules provide the following features:

• 2-location output channel list. You can update both DACs simultaneously at up to 50 kSamples/s

• 12-bit resolution

• One 32-bit counter/timer channel

• Internal and external A/D clock sources

• Internal and external A/D trigger sources

• No external power supply required

Digital

I/O

Channel-Gain List

Overview

All modules support a 32-location channel-gain list. You can cycle through the channel-gain list using continuous scan mode or triggered scan mode.

Counter/Timer Channel

All modules support one 32-bit counter/timer (C/T) channel that performs event counting, frequency measurement, edge-to-edge measurement, and rate generation (continuous pulse output) operations.

Supported Software

The following software is available for use with the DT9812, DT9813, and DT9814 modules, and is provided on the ECON CD:

• Device Driver – The DT9812, DT9813, or DT9814 Device Driver allows you to use these modules with any of the supported software packages or utilities. Refer to Chapter 2 for more information on loading the device driver.

• GO! application – The GO! application provides a quick way to measure and control data from an ECONseries module right out of the box. The following instrument views make acquiring data and controlling signals easy: oscilloscope, chart recorder, file viewer, digital voltmeter, waveform generator, digital input, digital output, counter, and rate generator. Refer to Chapter 5 for more information on using this application.

• DataAcq SDK – Use the Data Acq SDK if you want to develop your own application software for your modules using the Microsoft C compiler; the DataAcq SDK complies with the DT-Open Layers standard.

Chapter 1

• DTx-EZ – Use this optional software package if you want to use ActiveX controls to access the capabilities of your modules using Microsoft Visual Basic or Visual C++; DTx-EZ complies with the DT-Open Layers

standard.

• 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.

• DT-LV Link – Use this optional software package if you want to use the LabVIEW graphical programming language to access the capabilities of your modules.

• DT Measure Foundry – An evaluation version of this software is included or provided via a link on the ECON CD. DT Measure Foundry is drag-and-drop test and measurement application builder designed to give you top performance with ease-of-use development. Order the full development version of this software package to develop your own application using real hardware.

Getting Started Procedure

The flow diagram shown in Figure 1 illustrates the steps needed to get started using the modules. This diagram is repeated in each chapter; the shaded area in the diagram shows you where you are in the getting started procedure.

Prepare to Use the Module

(see Chapter 2 starting on page 23)

Set Up and Install the Module

(see Chapter 3 starting on page 29)

Overview

Wire Signals to the Module

(see Chapter 4 starting on page 37)

Verify the Operation of the Module

(see Chapter 5 starting on page 53)

Figure 1: Getting Started Flow Diagram

Chapter 1

Part 1: Getting Started

Preparing to Use a Module

Unpacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Checking the System Requirements . . . . . . . . . . . . . . . . . . . . . . . 25

Installing the Software. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Chapter 2

Prepare to Use the Module

(this chapter)

Set Up and Install the Module

(see Chapter 3 starting on page 29)

Wire Signals to the Module

(see Chapter 4 starting on page 37)

Verify the Operation of the Module

(see Chapter 5 starting on page 53)

Unpacking

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

• DT9812-2.5V, DT9812-10V, DT9813-10V, or DT9814-10V module

• ECON CD

•USB cable

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. 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).

Once you have unpacked your module, check the system requirements, as described in the next section.

Preparing to Use a Module

Checking the System Requirements

For reliable operation, your DT9812, DT9813, and DT9814 modules require the following:

• Windows 2000 or Windows XP (Professional Edition) operating system.

For USB Ver. 2.0 support, make sure that you install Service Pack 2 (for Windows XP) or Service Pack 4 (for Windows 2000). In addition, for some systems, you may have to disable standby mode. If you are not sure whether you are using USB Ver. 1.1 or Ver. 2.0, run the Open Layers Control Panel applet, described on

page 31.

• One or more USB ports (Ver. 2.0 or Ver. 1.1). USB Ver. 2.0 is recommended for optimal performance.

•One CD-ROM drive.

Once you have verified that your system meets the system requirements, install the software, as described in the next section.

Chapter 2

Installing the Software

Note: Even if you already have a previous DT9812 Series module

and associated drivers installed, you must install the latest driver software to support any DT9812 Series module you add to your system.

To install the device driver, Data Acq SDK, DTx-EZ, and the GO! application, do the following:

1. Insert the ECON CD into your CD-ROM drive. If the software runs automatically (the default condition), continue with step 4.

2. If the software does not run automatically, click Start from the Task Bar, and then click Run. The Run dialog box appears.

3. In the Command Line edit box, enter D:\Setup.Exe.

If your CD-ROM is not in drive D:, enter the letter of the drive where your CD-ROM is located. The welcome screen appears.

4. Click Install Drivers and GO!

5. Click Install now!

The installation wizard appears.

6. Click Next.

The wizard prompts you for the destination location.

7. Either change the directory path and/or name using Browse or accept the default directory (C:\Program Files\Data Translation), and then click Next.

8. Click Next to copy the files.

9. Click Finish.

Preparing to Use a Module

10. If you want to download and install an evaluation version of DT Measure Foundry, do the following:

a. Click Install Additional Software, and then click Download

now! under the DT Measure Foundry section.

b. Click the Open option from the Internet Explorer File

Download dialog box.

The setup program of DT Measure Foundry evaluation is automatically downloaded and started.

c. Follow the installation prompts.

11. If you want to install DT-LV Link, click Install Additional Software, and then click Install now! under the LabVIEW Link

section, and follow the installation prompts.

12. When you have finished the installation process, click Quit Installer.

Continue with the instructions in Chapter 3 starting on page 29.

Chapter 2

Setting Up and Installing

the Module

Attaching Modules to the Computer. . . . . . . . . . . . . . . . . . . . . . . 31

Changing the Name of a Module (Optional) . . . . . . . . . . . . . . . . 35

Chapter 3

Prepare to Use the Module

(see Chapter 2 starting on page 23)

Set Up and Install the Module

(this chapter)

Wire Signals to the Module

(see Chapter 4 starting on page 37)

Verify the Operation of the Module

(see Chapter 5 starting on page 53)

Note: The DT9812, DT9813, and DT9814 modules are factory-calibrated. The DT9812-2.5V module requires no further adjustment. If you want to recalibrate the DT9812-10V, DT9813-10V, or DT9814-10V module, refer to instructions on page 151.

Setting Up and Installing the Module

Attaching Modules to the Computer

This section describes how to attach a module to the host computer.

Note: Most computers have several USB ports that allow direct connection to USB devices. If your application requires more modules than you have USB ports for, you can expand the number of USB devices attached to a single USB port by using expansion hubs. For more information, refer to page 33.

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.

You must install the device driver before connecting your module to the host computer. See “Installing the Software” on page 26.

Connecting Directly to the USB Ports

To connect DT9812, DT9813, or DT9814 modules directly to the USB ports of your computer, do the following:

1. Attach one end of the USB cable to the USB port on the module.

2. Attach the other end of the USB cable to one of the USB ports on

the host computer, as shown in Figure 2.

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

Chapter 3

DT9812-2.5V, DT9812-10V, DT9813-10V, or DT9814-10V Modules

USB Ports

Host Computer

USB Cable

Figure 2: Attaching the Module to the Host Computer

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

If the module is attached correctly, the LED on the module turns green.

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

Connecting to an Expansion Hub

Setting Up and Installing the Module

Expansion hubs are powered by their own external power supply. Theoretically, you can connect up to five expansion hubs to a USB port on the host computer. However, the practical number of DT9812, DT9813, and/or DT9814 modules that you can connect to a single USB port depends on the throughput you want to achieve. Each of the hubs supports up to four modules.

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

1. Attach one end of the USB cable to the 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 expansion 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.

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

If the module is attached correctly, the LED on the module turns green.

5. Repeat these steps until you have attached the number of expansion hubs (up to five) and modules (up to four per hub) that you require. Refer to Figure 3.

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

Chapter 3

ECONseries Module

USB Cables

Host Computer

USB Cable

Power Supply for Hub

ECONseries Module

USB Cables

ECONseries Module

USB Cable

Expansion Hubs

Power Supply for Hub

ECONseries Module

Figure 3: Attaching Multiple DT9812, DT9813, and/or DT9814 Modules

Using Expansion Hubs

Setting Up and Installing the Module

Changing the Name of a Module (Optional)

To change the name of a module, configure the device driver as follows:

1. From the Windows Start menu, select Settings|Control Panel.

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

The Data Acquisition Control Panel dialog box appears.

3. Click the DT9812, DT9813, or DT9814 module that you want to rename, and then click Edit Name.

4. Enter a new name for the module, and then click OK. The name is used to identify the module in all subsequent applications.

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

6. Repeat steps 3 to 5 for the other modules that you want to

configure.

7. Close the Data Acquisition Control Panel dialog box.

Continue with the instructions on wiring in Chapter 4 starting on

page 37.

Chapter 3

Wiring Signals to the Module

Preparing to Wire Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Connecting Analog Input Signals . . . . . . . . . . . . . . . . . . . . . . . . . 43

Connecting Analog Output Signals. . . . . . . . . . . . . . . . . . . . . . . . 44

Connecting Digital I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Connecting Counter/Timer Signals . . . . . . . . . . . . . . . . . . . . . . . 47

Chapter 4

Prepare to Use a Module

(see Chapter 2 starting on page 23)

Set Up and Install the Module

(see Chapter 3 starting on page 29)

Wire Signals to the Module

(this chapter)

Verify the Operation of the Module

(see Chapter 5 starting on page 53)

Preparing to Wire Signals

CAUTION:

Wiring Signals to the Module

To avoid electrostatic sensitivity, unplug your DT9812, DT9813, or DT9814 module from the computer before wiring signals.

This section provides information about wiring signals to a DT9812-2.5V, DT9812-10V, DT9813-10V, or DT9814-10V module.

Wiring Recommendations

Keep the following recommendations in mind when wiring signals to an ECONseries module:

• Use individually shielded twisted-pair wire (size 16 to 26 AWG) in highly noisy electrical environments.

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

• To avoid noise, do not locate the box 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.

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

• Connect all unused analog input channels to analog ground.

Wiring Locations

You wire signals to each module using the screw terminals on the module. Tabl e 4 lists the screw terminal assignments for the DT9812 modules; Table 5 the DT9813 module; Tab le 6 the DT9814 module.

Chapter 4

Table 4: DT9812-2.5V and DT9812-10V Screw Terminal

Assignments

Screw

Terminal

20 USB +5 V Out 40 Ext Trigger

19 Ground 39 Ext Clock

18 Counter 0 In 38 Ground

17 Counter 0 Out 37 Digital Output 7

16 Counter 0 Gate 36 Digital Output 6

15 Ground 35 Digital Output 5

14 DAC 1 34 Digital Output 4

13 DAC 1 Return 33 Digital Output 3

12 DAC 0 32 Digital Output 2

11 DAC 0 Return 31 Digital Output 1

10 2.5 V Reference

9 Analog Ground 29 Ground

8 Analog Input CH7 28 Digital Input 7

7 Analog Input CH6 27 Digital Input 6

Signal

Screw

Terminal

30 Digital Output 0

Signal

6 Analog Input CH5 26 Digital Input 5

5 Analog Input CH4 25 Digital Input 4

4 Analog Input CH3 24 Digital Input 3

3 Analog Input CH2 23 Digital Input 2

2 Analog Input CH1 22 Digital Input 1

1 Analog Input CH0 21 Digital Input 0

a. For the DT9812-10V module, this reference is 2.5 V. For the DT9812-2.5V

module, this reference is 2.44 V.

Wiring Signals to the Module

Table 5: DT9813-10V Screw Terminal Assignments

Screw

Terminal

Signal

Screw

Terminal

Signal

20 USB +5 V Out 40 Ext Trigger

19 Ground 39 Ext Clock

18 Counter 0 In 38 Ground

17 Counter 0 Out 37 Digital Input 3

16 Counter 0 Gate 36 Digital Input 2

15 Ground 35 Digital Input 1

14 DAC 1 34 Digital Input 0

13 DAC 1 Return 33 Digital Output 3

12 DAC 0 32 Digital Output 2

11 DAC 0 Return 31 Digital Output 1

10 2.5 V Reference 30 Digital Output 0

9 Analog Ground 29 Ground

8 Analog Input CH7 28 Analog Input CH15

7 Analog Input CH6 27 Analog Input CH14

6 Analog Input CH5 26 Analog Input CH13

5 Analog Input CH4 25 Analog Input CH12

4 Analog Input CH3 24 Analog Input CH11

3 Analog Input CH2 23 Analog Input CH10

2 Analog Input CH1 22 Analog Input CH9

1 Analog Input CH0 21 Analog Input CH8

Chapter 4

Table 6: DT9814-10V Screw Terminal Assignments

Screw

Terminal

20 USB +5 V Out 40 Ext Trigger

19 Ground 39 Ext Clock

18 Counter 0 In 38 Ground

17 Counter 0 Out 37 Analog Input CH23

16 Counter 0 Gate 36 Analog Input CH22

15 Ground 35 Analog Input CH21

14 DAC 1 34 Analog Input CH20

13 DAC 1 Return 33 Analog Input CH19

12 DAC 0 32 Analog Input CH18

11 DAC 0 Return 31 Analog Input CH17

10 2.5 V Reference 30 Analog Input CH16

9 Analog Ground 29 Ground

8 Analog Input CH7 28 Analog Input CH15

7 Analog Input CH6 27 Analog Input CH14

Signal

Screw

Terminal

Signal

6 Analog Input CH5 26 Analog Input CH13

5 Analog Input CH4 25 Analog Input CH12

4 Analog Input CH3 24 Analog Input CH11

3 Analog Input CH2 23 Analog Input CH10

2 Analog Input CH1 22 Analog Input CH9

1 Analog Input CH0 21 Analog Input CH8

Wiring Signals to the Module

Connecting Analog Input Signals

The DT9812-2.5V and DT9812-10V modules support 8 single-ended analog input channels. The DT9813-10V module supports 16 single-ended analog input channels; the DT9814-10V supports 24.

Figure 4 shows how to connect single-ended voltage input signals

(channels 0 and 1, in this case) to the screw terminals of the module.

Analog Ground

source 1

Vsource 0

Signal Source

Figure 4: Connecting Single-Ended Inputs

Analog In 1

Analog In 0

ECONseries Module

Chapter 4

Connecting Analog Output Signals

The DT9812, DT9813, and DT9814 modules support two analog output channels (DAC0 and DAC1). Figure 5 shows how to connect an analog output voltage signal (DAC0, in this case) to one of these modules.

Load

DAC0

DAC0 Return

ECONseries Module

Figure 5: Connecting Analog Outputs to a Screw Terminal Panel

Connecting Digital I/O Signals

The DT9812-2.5V and DT9812-10V modules support eight fixed digital input lines and eight fixed digital output lines. The DT9813-10V module supports four fixed digital input lines and four fixed digital output lines.

Figure 6 shows how to connect digital input signals (lines 0 and 1, in

this case) to the screw terminals of a DT9812-2.5V or DT9812-10V module.

Wiring Signals to the Module

DT9812-2.5V or DT9812-10V Module

Figure 6: Connecting Digital Inputs

For a DT9813-10V module, connect digital input lines 0 and 1 to screw terminals 34 and 35, respectively.

Ground

Digital Input 1

Digital Input 0

TTL Inputs

Chapter 4

Figure 7 shows how to connect digital output signals (line 0, in this

case) to the screw terminals of a DT9812-2.5V, DT9812-10V, or DT9813-10V module.

DT9812 Series or DT9813 Module

Ground

Out = LED On

Digital Output 0

500 Ω

5 V

Figure 7: Connecting Digital Outputs

Note: The DT9813-10V module has only four digital output lines, at screw terminals 30 through 33.

Wiring Signals to the Module

Connecting Counter/Timer Signals

The DT9812, DT9813, and DT9814 modules provide one counter/timer that you can use for the following operations:

• Event counting

• Frequency measurement

• Edge-to-edge measurement

• Continuous pulse output (rate generation)

This section describes how to connect counter/timer signals for these operation modes. Refer to Chapter 6 for more information about using the counter/timers.

Event Counting

Figure 8 shows how to connect counter/timer signals to the screw

terminals on the module to perform an event counting operation using an external gate.

In this example, the counter counts the number of rising edges that occur on the Counter 0 In signal when the Counter 0 Gate signal is in the active state (as specified by software). Refer to “Counter/Timer

Features” on page 91 for more information.

Chapter 4

Signal Source

Ground

Counter 0 In

External Gating Switch

Counter 0 Gate

Ground

ECONseries Module

Figure 8: Connecting Counter/Timer Signals for an Event Counting

Operation Using an External Gate

Figure 9 shows how to connect counter/timer signals to the screw

terminals on the module to perform an event counting operation without using a gate (also called a software gate). The counter counts the number of rising edges that occur on the Counter 0 In signal.

Ground

Signal Source

ECONseries Module

Counter 0 In

Figure 9: Connecting Counter/Timer Signals for an Event Counting

Operation Without Using a Gate

Frequency Measurement

Wiring Signals to the Module

Signal Source

One way to measure frequency is to use the same wiring as a standard event counting application that does not use a gate (see

Figure 9), and then call the olDaMeasureFrequency function to

determine the duration over which to count the number of pulses connected to the Counter 0 In signal. The frequency of the Counter 0 In signal is the number of counts divided by the duration of the olDaMeasureFrequency function.

If you need more accuracy than the olDaMeasureFrequency function provides, you can connect a pulse of a known duration to the Counter 0 Gate signal, as shown in Figure 10. In this case, the frequency of the Counter 0 In signal is the number of counts divided by the period of the signal connected to the Counter 0 Gate input.

Ground

Counter 0 In (Number of pulses counted during gate period)

Counter 0 Gate

Known Signal Source

(Determines period for count)

ECONseries Module

Figure 10: Connecting Counter/Timer Signals for a Frequency Measurement

Operation Using an External Pulse

Chapter 4

Edge-to-Edge Measurement

Figure 11 shows how to connect counter/timer signals to the module

to perform an edge-to-edge measurement operation on one signal source. The counter measures the number of counts between the start edge (in this case, a rising edge on the Counter 0 Gate signal) and the stop edge (in this case, another rising edge on the Counter 0 Gate signal).

You specify the start edge and the stop edge in software. Refer to

page 96 for more information.

ECONseries Module

Ground

Signal Source

Counter 0 Gate

In this example, the software returns the number of counts between the two rising edges

Figure 11: Connecting Counter/Timer Signals for an

Edge-to-Edge Measurement Operation

Wiring Signals to the Module

You can use edge-to-edge measurement to measure the following characteristics of a signal:

• Pulse width – The amount of time that a signal pulse is in a high or a low state, or the amount of time between a rising edge and a falling edge or between a falling edge and a rising edge. You can calculate the pulse width as follows:

− Pulse width = Number of counts/24 MHz

• Period – The time between two occurrences of the same edge (rising edge to rising edge, or falling edge to falling edge). You can calculate the period as follows:

− Period = 1/Frequency

− Period = Number of counts/24 MHz

• Frequency – The number of periods per second. You can calculate the frequency as follows:

− Frequency = 24 MHz/Number of Counts

Chapter 4

Rate Generation

Figure 12 shows how to connect counter/timer signals to the screw

terminals of a module to perform a rate generation (continuous pulse output) operation; in this example, an external gate is used.

Heater Controller

Ground

Counter 0 Out

External Gating Switch

Counter 0 Gate

Ground

ECONseries Module

Figure 12: Connecting Counter/Timer Signals for a Rate Generation

Operation Using an External Gate

Verifying the Operation

of a Module

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Using the Oscilloscope Function . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Using the Chart Recorder Function. . . . . . . . . . . . . . . . . . . . . . . . 58

Using the Voltmeter Function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Using the File Viewer Function . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Using the Waveform Generator Function. . . . . . . . . . . . . . . . . . . 61

Using the Digital Input Function . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Using the Digital Output Function . . . . . . . . . . . . . . . . . . . . . . . . 63

Using the Counter Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Using the Rate Generator Function . . . . . . . . . . . . . . . . . . . . . . . . 65

Chapter 5

Prepare to Use a Module

(see Chapter 2 starting on page 23)

Set Up and Install the Module

(see Chapter 3 starting on page 29)

Wire Signals to the Module

(see Chapter 4 starting on page 37)

Verify the Operation of the Module

(this chapter)

Overview

The GO! application allows you to measure and control signals from your DT9812-2.5V, DT9812-10V, DT9813-10V, and DT9814-10V modules right out of the box. Simply install the ECONseries software, connect your module to the PC, connect your signals to the module, and run the GO! application from the Data Translation, Inc| ECONseries program group.

Verifying the Operation of a Module

The GO! application provides the following instrument-like functions for data acquisition, control, and display (the software shows only those functions that are supported by your module):

• Oscilloscope

− Stream, plot, and analyze data from up to eight analog input

channels

− Zoom in or out of live signals

− Select the trigger type, level, and channel

− Print your data or save it to an Excel file

• Chart Recorder

− Record up to 31,990 data points from up to eight analog input

channels

− Log data to an Excel file

•Voltmeter

− Measure data from up to eight analog input channels and

view it in a 5-digit digital display

− Display the maximum or true root mean square (RMS) value

• File Viewer

− Load a previously saved Excel file

− Scroll, zoom, or print your data

Chapter 5

• Function Generator

− Generate DC, sine, rectangle, or triangle waveforms from up

to two analog output channels

− Select the frequency, amplitude, offset, and duty cycle of your

signal

• Digital Input − Monitor the status of the digital inputs using LEDs

• Digital Output − Control the state of the digital outputs using switches

• Counter − Count pulses from the counter/timer for 1, 2, or 5 seconds or for an unlimited time

• Rate Generator − Control the frequency of a continuous pulse output signal from the counter/timer

The GO! application automatically detects and configures the first installed ECONseries module. If you have multiple ECONseries modules installed, you can select the module to use.

Notes: If no module is connected, the GO! application displays a message box. If you want to continue, plug a DT9812, DT9813, or DT9814 module into any USB port of your PC, and then click Rescan. Otherwise, click Quit to exit from the GO! application.

If you have multiple modules, you can run multiple instances of the GO! application, if you wish. Each instance of the application detects the available (not already in use) modules for your convenience.

Press F1 at any time to get help on any of the functions of the GO! application.

Verifying the Operation of a Module

Using the Oscilloscope Function

The verify the analog input operation of your module using the Oscilloscope function of the GO! application, do the following:

1. Connect a known voltage source, such as the output of a function generator, to analog input channel 0 on the module (single-ended mode). Refer to page 43 for an example of how to connect a single-ended analog input.

2. Under Visible Channels on the Oscilloscope tab, ensure that only channel 0 is selected.

The analog input data from channel 0 is continuously displayed.

3. Zoom into your data by using your left mouse button to create a zoom rectangle around the region that you are interested in.

4. When you are finished, snap back to the standard voltage range of the module, by clicking the Unzoom button.

Chapter 5

Using the Chart Recorder Function

To verify the analog input operation of your module using the Chart Recorder function of the GO! application, do the following:

2. Under Visible Channels on the Chart Recorder tab, ensure that only channel 0 is selected.

3. Click Start Recording, and enter Te st for the filename.

The analog input data from channel 0 is displayed on the screen and logged to the Test.xls file.

4. After a few seconds, click Stop Recording.

5. Launch Excel and open the file called Test.xls to review the data

you just recorded.

Using the Voltmeter Function

To verify the analog input operation of your module using the Voltmeter function of the GO! application, do the following:

Verifying the Operation of a Module

2. Under Visible Channels on the Voltmeter tab, ensure that only channel 0 is selected.

3. Click Normal under Display Settings.

The analog input data from analog input channel 0 is converted into digital format and displayed.

Note that the 5-digit display is refreshed twice a second.

Chapter 5

Using the File Viewer Function

To verify the analog input operation of your module using the File Viewer function of the GO! application, do the following:

2. Under Visible Channels on the Chart Recorder tab, ensure that only channel 0 is selected.

3. Click Start Recording, and enter Te st for the filename.

The analog input data from channel 0 is displayed on the screen and logged to the Test.xls file.

4. After a few seconds, click Stop Recording.

5. Click on the File Viewer tab, and click Open File.

6. Click on the filename Te s t .x l s .

7. Click Open.

8. Scroll through the data in the file using the slider at the bottom of the File Viewer screen.

Verifying the Operation of a Module

Using the Waveform Generator Function

To verify the analog output operation of your module using the Waveform Generator function of the GO! application, do the following:

1. Connect an oscilloscope or voltmeter to analog output channel 0 on the module. Refer to page 44 for an example of how to connect analog output signals.

2. For Waveform Ch0, select Sine.

Notice the waveform that is output on your oscilloscope or voltmeter display.

3. If you wish, use the Amplitude sliders for Ch 0 to change the amplitude of the waveform. For the DT9812-2.5V module, the amplitude can range between 0 and 2.44 V.

For the DT9812-10V, DT9813-10V, and DT9814-10V modules, the amplitude can range between −10 V and +10 V.

4. If you wish, use the Frequency sliders for Ch 0 to change the frequency of the module. The frequency of both modules can range between 0 and 50 kHz.

5. If you wish, use the Offset sliders for Ch 0 to change the offset of the module. For the DT9812-2.5V module, the offset can range between 0 and 2.44 V.

For the DT9812-10V, DT9813-10V, and DT9814-10V modules, the offset can range between −10 V and +10 V.

Chapter 5

Using the Digital Input Function

To verify the digital input operation of your DT9812-2.5V, DT9812-10V, or DT9813-10V module using the Digital Input function of the GO! application, do the following:

1. Connect a digital input signal to a digital input line on the module. Refer to page 45 for an example of how to connect a digital input.

2. Read the status of the LEDs.

If digital input line 0 is high, the LED for line 0 turns green (on). If digital input line 0 is low, the LED for line 0 turns gray (off).

The DT9812-2.5V and DT9812-10V modules support eight fixed digital input lines. The DT9813-10V supports four fixed digital input lines.

Verifying the Operation of a Module

Using the Digital Output Function

To verify the digital output operation of your DT9812-2.5V, DT9812-10V, or DT9813-10V module using the Digital Output function of the GO! application, do the following:

1. Connect a device to a digital output line on the module. Refer to

page 45 for an example of how to connect a digital output.

2. Click the switches to change the state of your device.

3. Check that the device has been changed as expected.

For example, if you connect a simple set of LEDs, the LED corresponding to a line you switch on with the Digital Output function should turn green (on).

The DT9812-2.5V and DT9812-10V modules support eight fixed digital output lines. The DT9813-10V supports four fixed digital output lines.

Chapter 5

Using the Counter Function

To verify the event counting operation of your module using the Counter function of the GO! application, do the following:

1. Wire an external clock source to the Counter 0 In signal on your module. (Refer to page 47 for an example of how to connect an external clock to the counter/timer channel.)

2. Click 2 Seconds, and click Start Counting.

The number of counts is displayed on the screen. When 2 seconds have elapsed, the operation stops automatically.

Verifying the Operation of a Module

Using the Rate Generator Function

To verify the rate generation operation of your module using the Rate Generator function of the GO! application, do the following:

1. Connect a scope or similar device that accepts a pulse output signal to the Counter 0 Out signal of your module. (Refer to page

52 for an example of how to connect signals for rate generation.)

2. Use the slider to change the frequency of the continuous pulse output signal.

If you are using a scope, you can see the frequency of the pulse output signal change as you move the slider.

Chapter 5

Part 2: Using Your Module

Principles of Operation

Analog Input Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Analog Output Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

Digital I/O Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

Counter/Timer Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

Chapter 6

Figure 13 shows a block diagram of the DT9812-2.5V and

DT9812-10V modules.

+2.5 V Reference*

8-Channel Multiplexer

A/D Ch7

A/D Ch6

A/D Ch5

A/D Ch4

A/D Ch3

A/D Ch2

A/D Ch1

A/D Ch0

ESD Protected to 4000 V

DAC 1

DAC 0

From USB

Por t

A/D Clock

12-Bit A/D

Converter

12-Bit D/A

Converter

Power

Supply

32-Bit

Counter/Timer

+5 V

C/T Out 0 C/T Gate 0

C/T In 0

External Clock

External Trigger

Digital

I/O

ESD Protected to 4000 V

DOUT7

DOUT0

DIN7

DIN0

USB 2.0 or 1.1

Por t

* Note: For the DT9812-10V module, the reference is 2.5 V. For the DT9812-2.5V module, the reference is 2.44 V.

Input FIFO

Figure 13: Block Diagram of the DT9812-2.5V and DT9812-10V Modules

Principles of Operation

Figure 14 shows a block diagram of the DT9813-10V module.

+2.5 V Reference

16-Channel Multiplexer

A/D Ch15

A/D Ch14

A/D Ch13

A/D Ch2

A/D Ch1

A/D Ch0

ESD Protected to 4000 V

DAC 1

DAC 0

From USB

Por t

A/D Clock

12-Bit A/D

Converter

12-Bit D/A

Converter

Power

Supply

32-Bit

Counter/Timer

+5 V

C/T Out 0 C/T Gate 0

C/T In 0

External Clock

External Trigger

Digital

I/O

ESD Protected to 4000 V

DOUT3

DOUT0

DIN3

DIN0

USB 2.0 Port

Figure 14: Block Diagram of the DT9813-10V Module

Input FIFO

Chapter 6

Figure 15 shows a block diagram of the DT9814-10V module.

+2.5 V Reference

24-Channel Multiplexer

A/D Ch23

A/D Ch22

A/D Ch21

A/D Ch2

A/D Ch1

A/D Ch0

ESD Protected to 4000 V

DAC 1

DAC 0

From USB

Por t

A/D Clock

12-Bit A/D

Converter

12-Bit D/A

Converter

Power

Supply

32-Bit

Counter/Timer

+5 V

C/T Out 0 C/T Gate 0

C/T In 0

External Clock

External Trigger

ESD Protected to 4000 V

USB 2.0 Port

Input FIFO

Figure 15: Block Diagram of the DT9814-10V Module

Analog Input Features

This section describes the following features of analog input (A/D) operations on the DT9812, DT9813, and DT9814 modules:

• Input resolution, described below

• Analog input channels, described below

• Input ranges and gains, described on page 75

Principles of Operation

• Input sample clock sources, described on page 77

• Analog input conversion modes, described on page 78

• Input triggers, described on page 80

• Data format and transfer, described on page 81

• Error conditions, described on page 82

Input Resolution

The DT9812, DT9813, and DT9814 modules provide a resolution of 12-bits. Note that the resolution is fixed; you cannot program it in software.

Analog Input Channels

The DT9812-2.5V and DT9812-10V modules provide eight single-ended analog input channels. The DT9813-10V and DT9814-10V modules provide 16 and 24 analog input channels, respectively. The modules can acquire data from a single analog input channel or from a group of analog input channels.

The following subsections describe how to specify the channels.

Chapter 6

Specifying a Single Analog Input 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 78 for more information about single-value operations.

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

Specifying One or More Analog Input Channels

You can read data from one or more analog input channels using an analog input channel-gain 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 channels in the order you want to sample them. You can enter up to 32 entries in the channel-gain list. The channels are read in order from the first entry in the list to the last entry in the list. Refer to page 78 for more information about the supported conversion modes.

The maximum rate at which the module can read the analog input channels is 50 kSamples/s. Therefore, if you specify two analog input channels in the channel-gain list, the maximum sampling rate is 25 kSamples/s for each channel. Likewise, if you specify 16 analog input channels in the channel-gain list, the maximum sampling rate is

3.125 kSamples/s for each channel.

Input Ranges and Gains

Principles of Operation

The DT9812-2.5V features an input range of 0 to 2.44 V, while the DT9812-10V, DT9813-10V, and DT9814-10V modules feature an input range of ±10 V. Use software to specify the input range. Note that this is the range for the entire analog input subsystem, not the range per channel.

The modules support programmable gains to allow many more effective input ranges. Tab le 7 lists the supported gains and effective input ranges for each module.

Table 7: Effective Input Range

Unipolar

Module Gain

DT9812-2.5V 1 0 to 2.44 V

2 0 to 1.22 V −

4 0 to 0.610 V −

8 0 to 0.305 V −

16 0 to 0.1525 V −

Input Range

Bipolar

Input Range

−

DT9812-10V DT9813-10V DT9814-10V

1 − ±10 V

− ±5 V

− ±2.5 V

− ±1.25 V

Chapter 6

For each channel on the module, choose the gain that has the smallest effective range that includes the signal you want to measure. For example, if you are using a DT9812-2.5V module and the range of your analog input signal is 0 to 1.05 V, specify a range of 0 to 2.44 V for the module and use a gain of 2 for the channel; the effective input range for this channel is then 0 to 1.22 V, which provides the best sampling accuracy for that channel.

The way you specify gain depends on how you specified the channels, as described in the following subsections.

Specifying the Gain for a Single Channel

The simplest way to specify gain for a single channel is to specify the gain for a single-value analog input operation using software; refer to

page 78 for more information about single-value operations.

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

Specifying the Gain for One or More Channels

You can specify the gain for one or more analog input channels using an analog input channel-gain list. Using software, set up the channel-gain list by specifying the gain for each entry in the list.

For example, assume the analog input channel-gain list contains three entries: channels 5, 6, and 7 and gains 2, 4, and 1. A gain of 2 is applied to channel 5, a gain of 4 is applied to channel 6, and a gain of 1 is applied to channel 7.

Input Sample Clock Sources

Principles of Operation

You can use one of the following clock sources to pace an analog input operation:

• Internal clock – Using software, specify the clock source as internal and the clock frequency at which to pace the operation. The minimum frequency of the internal clock is 30 Hz; the maximum frequency of the internal clock is 50 kHz.

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 2 kHz signal, specify a sampling frequency of at least 4 kHz. Doing so avoids an error condition called aliasing, in which high frequency input components erroneously appear as lower frequencies after sampling.

• External clock – An external clock is useful when you want to pace acquisitions at rates not available with the internal clock or when you want to pace at uneven intervals. The minimum frequency of the external clock can be less than 30 Hz; the maximum frequency of the external clock is 40 kHz.

Connect an external clock to the Ext Clock In signal on the module. Conversions start on the rising edge of the external clock input signal.

Using software, specify the clock source as external. The clock frequency is always equal to the frequency of the external sample clock input signal that you connect to the module.

Chapter 6

Analog Input Conversion Modes

The DT9812, DT9813, and DT9814 modules support the following conversion modes:

• Single-value operations

• Continuous scan operations

Single-Value Operations

Single-value operations are the simplest to use. Using software, you specify the range, gain, and analog input channel. The module acquires the data from the specified channel and returns the data immediately. For a single-value operation, you cannot specify a clock source, trigger source, scan mode, or buffer.

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

Continuous Scan Mode

Use continuous scan mode if you want to accurately control the period between conversions of individual channels in a channel-gain list.

When it receives a software trigger, the module cycles through the channel-gain list, acquiring and converting the data for each entry in the list (this process is defined as the scan). The module then wraps to the start of the channel-gain list and repeats the process continuously until either the allocated buffers are filled or until you stop the operation. Refer to page 80 for more information about buffers.

Principles of Operation

The conversion rate is determined by the frequency of the internal sample clock; refer to page 77 for more information about the internal sample clock. The sample rate, which is the rate at which a single entry in the channel-gain list is sampled, is determined by the frequency of the input sample clock divided by the number of entries in the channel-gain list.

To select continuous scan mode, use software to specify the data flow as continuous.

Figure 16 illustrates continuous scan mode using a channel-gain list

with three entries: channel 0, channel 1, and channel 2. In this example, analog input data is acquired on each clock pulse of the input sample clock. When it reaches the end of the channel-gain list, the module wraps to the beginning of the channel-gain list and repeats this process. Data is acquired continuously.

Chan 0

Input Sample Clock

Initial trigger event occurs

Chan 2

Chan 1

Figure 16: Continuous Scan Mode

Chan 0

Chan 1

Chan 2

Data acquired continuously

Chan 0

Chan 2

Chan 1

Chan 0

Chan 1

Chan 2

Chapter 6

Input Triggers

A trigger is an event that occurs based on a specified set of conditions. Acquisition starts when the module detects the initial trigger event and stops when the specified number of samples has been acquired (if the buffer wrap mode is none, described on page

80), or when you stop the operation. Note that when you stop the

operation, the module completes the reading of the channel-gain list.

The DT9812, DT9813, and DT9814 modules support the following trigger sources:

• Software trigger 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.

• External digital (TTL) trigger event occurs when the module detects a high-to-low transition on the Ext Trigger In signal connected to the module. Using software, specify a falling-edge external digital trigger (trigger source extra).

Data Transfer

Before you begin acquiring data, you must allocate buffers to hold the data. A Buffer Done message is returned whenever a buffer is filled. This allows you to move and/or process the data as needed.

We recommend that you allocate a minimum of three buffers for analog input operations, specifying one of the following buffer wrap modes in software:

• None

– Data is written to multiple allocated input buffers

continuously; when no more empty buffers are available, the operation stops. If wrap mode is none, the module guarantees gap-free data.

– A software trigger event occurs when you

– An external digital (TTL) trigger

• Multiple – Data is written to multiple allocated input buffers continuously; if no more empty buffers are available, the module overwrites the data in the current buffer, starting with the first location in the buffer. This process continues indefinitely until you stop it. If wrap mode is multiple, the module does not guarantee gap-free data.

Data Format

Principles of Operation

The DT9812-2.5V module uses binary data encoding to represent unipolar input ranges, while the DT9812-10V, DT9813-10V, and DT9814-10V modules use twos complement encoding to represent bipolar input ranges.

In software, the analog input value is returned as a code. To convert the code to voltage, use the information in the following subsections.

Converting a Binary Code to a Voltage

To convert a binary code into a voltage on the DT9812-2.5V module, use the following formula:

Voltage = (2.44 * Code) / 4096

where,

• 2.44 is the full-scale range of the module (0 to +2.44V)

• Code is the raw count used by the software to represent the voltage in binary notation

• 4096 is the input resolution (12 bits)

• Voltage is the analog voltage

For example, if the software returns a code of 3072 for the analog input operation, determine the analog input voltage as follows:

Voltage = (2.44 * 3072) / 4096 = 1.83 V

Chapter 6

Converting a Twos Complement Code to a Voltage

To convert a twos complement code into a voltage on the DT9812-10V, DT9813-10V, or DT9814-10V module, use the following formula:

Voltage = (20 * Code) / 4096

where,

• 20 is the full-scale range of the module (-10V to +10V)

• Code is the raw count used by the software to represent the voltage

• 4096 is the input resolution (12 bits)

• Voltage is the analog voltage

For example, assume that the software returns a code of 1040 for the analog input value. Determine the analog input voltage as follows:

Voltage = (20 * 1040) /4096 = 5.078 V

Error Conditions

An overrun condition is reported if the A/D sample clock rate is too fast. This error is reported if a new A/D sample clock pulse occurs while the ADC is busy performing a conversion from the previous A/D sample clock pulse. It is up to the host application to handle this error by either ignoring the error or stopping acquisition. To avoid this error, use a slower sampling rate or increase the buffer size and/or number of buffers.

Analog Output Features

This section describes the following features of analog output operations:

• Output resolution, described below

• Analog output channels, described below

• Output ranges and gains, described on page 84

Principles of Operation

• Output trigger, described on page 85

• Output clock, described on page 85

• Data format and transfer, described on page 88

• Error conditions, described on page 89

Output Resolution

The modules provide a fixed output resolution of 12 bits. Note that the resolution is fixed; it cannot be programmed in software.

Analog Output Channels

DT9812, DT9813, and DT9814 modules provide two analog output channels (DACs). The modules can output data from a single analog output channel or from both analog output channels.

The following subsections describe how to specify the channels.

Specifying a Single Analog Output Channel

The simplest way to output data from a single analog output channel is to use single-value analog output mode, specifying the analog output channel that you want to update; refer to page 86 for more information about single-value operations.

Chapter 6

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

Specifying Analog Output Channels

You can output data continuously from one or both analog output channels using the output channel list. If you want to output data from one analog output channel continuously, specify either 0 (DAC0) or 1 (DAC1) in the channel output list. If you want to output data to both analog output channels continuously, specify the output channel list in the following order: 0, 1.

Then, use software to specify the data flow mode as continuous for the D/A subsystem; refer to page 85 for more information on continuous analog output operations.

Output Ranges and Gains

For the DT9812-2.5V module, a fixed output range of 0 to 2.44 V is provided. For the DT9812-10V, DT9813-10V, and DT9814-10V, a fixed output range of ±10 V is provided.

Through software, specify the range for the entire analog output subsystem (0 to 2.44 V for the DT9812-2.5 V module or ±1 0 V for the DT9812-10V, DT9813-10V, and DT9814-10V modules), and specify a gain of 1 for each channel.

Output Trigger

Principles of Operation

A trigger is an event that occurs based on a specified set of conditions. The modules support a software trigger for starting analog output operations. Using a software trigger, the module starts outputting data when it receives a software command.

Using software, specify the trigger source for the D/A subsystem as a software trigger.

Output Clock

When in continuous output mode, described on page 86, you can update both analog output channels simultaneously using the internal clock on the module.

Using software, specify the clock source for the D/A subsystem as internal and specify the frequency at which to update the analog output channels (between 30 Hz to 50 kHz).

Note: The output clock frequency that you specify is frequency at which both analog output channels are simultaneously updated.

Output Conversion Modes

The DT9812, DT9813, and DT9814 modules support the following output conversion modes:

• Single-value output operations

• Continuous output operations

Chapter 6

Single-Value Operations

Single-value operations are the simplest to use but offer the least flexibility and efficiency. Use software to specify the analog output channel, and the value to output from the analog output channel. Since a single-value operation is not clocked, you cannot specify a clock source, trigger source, or buffer.

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

Continuous Output Mode

Use continuously paced analog output mode if you want to accurately control the period between D/A conversions or write a waveform to one or more analog output channels.

Use software to configure the output channel list, as described on

page 83. Then, allocate a buffer that contains the values to write to the

analog output channels that are specified in the output channel list. For example, if your output channel list contains DAC0 and DAC1, specify your buffer as follows: first value for DAC0, first value for DAC1, second value for DAC0, second value for DAC1, and so on.

When it receives the software trigger, the module starts writing output values to the analog output channels specified in the output channel list. The operation repeats continuously until either all the data is output from the buffers (if buffer wrap mode is none) or you stop the operation (if buffer wrap mode is multiple). Refer to page 88 for more information about buffer modes.

Note: Make sure that the host computer transfers data to the analog output channels fast enough so that they do not empty completely; otherwise, an underrun error results.

Principles of Operation

To select continuously paced analog output mode, use software to specify the data flow as continuous, the buffer wrap mode as none or multiple, the trigger source and output clock as internal, and the output clock frequency (between 30 Hz and 50 kHz).

To stop a continuously paced analog output operation, you can stop sending data to the module, letting the module stop when it runs out of data, or you can perform either an orderly stop or an abrupt stop using software. In an orderly stop, the module finishes outputting the specified number of samples, then stops; all subsequent triggers are ignored. In an abrupt stop, the module stops outputting samples immediately; all subsequent triggers are ignored.

Data Transfer

If you are using continuous output mode, you must allocate and fill multiple buffers with the appropriate data before starting the operation, and specify a buffer wrap mode in software.

The following buffer wrap modes are supported:

• None – Data is written from multiple output buffers continuously; when no more buffers of data are available, the continuous output operation stops. This mode guarantees gap-free data.

• Multiple – Data is written from multiple output buffers continuously; when no more buffers of data are available, the module returns to the first location of the first buffer and continues writing data. This process continues indefinitely until you stop it. This mode does not guarantee gap-free data.

A Buffer Done message is returned whenever the last value in a buffer is output. This allows you to fill the buffer or provide a new buffer, as needed.

Chapter 6

Note: An underrun error can result if your buffer size is too small, if you do not allocate enough buffers, or if your clock rate is too fast.

Data Format

The DT9812-2.5V module uses binary data encoding, while the DT9812-10V, DT9813-10V, and DT9814-10V modules use twos complement encoding.

In software, you need to supply a code that corresponds to the analog output value you want the module to output.

Converting a Voltage into a Binary Code

To convert a voltage into a binary code on the DT9812-2.5V module, use the following formula:

Code = Voltage / (2.44 / 4096)

where,

• 2.44 is the full-scale range of the module (0 to +2.44V)

• 4096 is the resolution (12 bits)

• Voltage is the analog output voltage

• Code is the raw count used by the software to represent the voltage in binary notation

For example, if you want to output a voltage of 2.0 V, determine the code value as follows:

Code = 2.0 / (2.44 / 4096) = 3357

Principles of Operation

Converting a Voltage to a Twos Complement Code

To convert a voltage into a twos complement code on the DT9812-10V, DT9813-10V, or DT9814-10V module, use the following formula:

Code = Voltage / (20 / 4096)

where,

• 20 is the full-scale range of the module (-10V to +10V)

• 4096 is the resolution (12 bits)

• Voltage is the analog output voltage

• Code is the raw count used by the software to represent the voltage in binary notation

For example, if you want to output a voltage of +5 V, determine the code as follows

Code = 5/ (20 / 4096) = 1024

Error Conditions

The modules can report an underrun error if the data for the analog output channels is not sent fast enough from the host computer. It is up to the host application to handle this error either by ignoring it or by stopping the output operation.

To avoid this error, try slowing down the clock rate, increasing the output buffer size, or allocating more output buffers.

Note: If no new data is available to be output by the analog output channels, the last value that was written to the analog output channels continues to be output.

Chapter 6

Digital I/O Features

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

• Digital I/O lines

•Resolution

•Operation modes

Digital I/O Lines

The DT9812-2.5V and DT9812-10V modules provide 8 dedicated digital input lines and 8 dedicated digital output lines. The DT9813-10V module provides 4 dedicated digital input lines and 4 dedicated digital output lines.

Using DT-Open Layers, you can specify the digital line that you want to read or write in a single-value digital I/O operation. Refer to page

91 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. On power up or reset, a low value (0) is output from each of the digital output lines.

Note: You can also read or write to the digital I/O lines using direct register calls. Refer to Appendix C for more information on these calls.

Resolution

The resolution of the digital ports on the DT9812-2.5V and DT9812-10V modules is fixed at 8-bits. The resolution of the digital ports on the DT9813-10V module is fixed at 4-bits.

Operation Modes

Principles of Operation

The DT9812 and DT9813 modules support single-value digital I/O operations only. For a single-value operation, use software to specify the digital I/O port (the gain is ignored). Data is then read from or written to the digital lines associated with that port.

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

Counter/Timer Features

This section describes the following features of counter/timer (C/T) operations:

• C/T channels, described below

• C/T clock sources, described on page 92

• Gate types, described on page 93

• Pulse types and duty cycles, described on page 93

• C/T operation modes, described on page 94

C/T Channels

The modules provide one 32-bit counter/timer (16 bits in rate generation mode). The counter accepts a C/T clock input signal (pulse input signal) and gate input signal, and outputs a pulse signal (clock output signal), as shown in Figure 17.

Chapter 6

C/T Clock Input SIgnal (internal or external)

Figure 17: Counter/Timer Channel

C/T Clock Sources

The following clock sources are available for the counter/timers:

• Internal clock – Through software, specify the clock source as internal, and specify the frequency at which to pace the counter/timer operation. The frequency of the internal C/T clock can range from 15 Hz to 12 MHz.

• External clock – An external clock is useful when you want to pace counter/timer operations at rates not available with the internal clock or if you want to pace at uneven intervals.

Counter

Gate Input Signal

(software or external

input)

Pulse Output Signal

Connect an external clock with a maximum recommended frequency of 6 MHz to the Counter 0 In signal on the module. Using software, specify the C/T clock source as external, and specify a clock divider between 2 and 65536 to determine the actual frequency at which to pace the counter/timer operation. For example, if you connect a 6 MHz external C/T clock and use a clock divider of 2, the resulting C/T output frequency is 3 MHz. Counter/timer operations start on the falling edge of the Counter 0 In signal.

Gate Types

Principles of Operation

The edge or level of the Counter 0 Gate signal determines when a counter/timer operation is enabled. Using software, you can specify one of the following gate types:

• None – A software command enables any counter/timer operation immediately after execution.

• Logic-high level external gate input – Enables a counter/timer operation when Counter 0 Gate is high, and disables a counter/timer operation when Counter 0 Gate is low. Note that this gate type is used for event counting and rate generation modes; refer to page 94 for more information about these modes.

• Falling-edge external gate input – Enables a counter/timer operation when a high-to-low transition is detected on the Counter 0 Gate signal. In software, this is called a low-edge gate type. Note that this gate type is used for edge-to-edge measurement mode; refer to page 96 for more information about these modes.

• Rising-edge external gate input – Enables a counter/timer operation when a low-to-high transition is detected on the Counter 0 Gate signal. In software, this is called a high-edge gate type. Note that this gate type is used for edge-to-edge measurement operations; refer to page 96 for more information about these modes.

Pulse Duty Cycles

Counter/timer output signals from the modules are high-to-low going signals.

The duty cycle (or pulse width) indicates the percentage of the total pulse output period that is active. In rate generation mode, the duty cycle is fixed at 50% for the DT9812, DT9813, and DT9814 modules.

Figure 18 illustrates a high-to-low going output pulse with a duty

cycle of 50%.

Chapter 6

Total Pulse Period

high pulse

low pulse

Active Pulse Width

Figure 18: Example of a Pulse Output SIgnal with a 50% Duty Cycle

(High-to-Low Going)

Counter/Timer Operation Modes

The modules support the following counter/timer operation modes:

• Event counting

• Frequency measurement

• Edge-to-edge measurement

• Rate generation

Event Counting

Use event counting mode if you want to count the number of falling edges that occur on Counter 0 In when the gate is active (high-level gate or software gate). Refer to page 93 for information about specifying the active gate type.

You can count a maximum of 4,294,967,296 events before the counter rolls over to 0 and starts counting again.

Principles of Operation

For event counting operations, use software to specify the counter/timer mode as count, the C/T clock source as external, and the active gate type as software or high-level.

Make sure that the signals are wired appropriately. Refer to

Chapter 4 for an example of connecting an event counting

application.

Frequency Measurement

Using software, specify the counter/timer mode as count, the clock source as external, and then call the olDaMeasureFrequency function.

Our function uses the Windows timer (which uses a resolution of 1 ms) to specify the duration. If you need more accuracy than the Windows timer provides, you can connect a pulse of a known duration to the Counter 0 Gate signal.

If you are using a known pulse connected to the gate pin for the duration, specify the active gate in software (high level or low level). When the operation starts, read the number of counts that occurred when the gate was active.

You can determine the frequency of the clock input signal using the following equation:

Frequency Measurement = Number of Events Measurement Period

Make sure that the signals are wired appropriately. Refer to

Chapter 4 for an example of connecting a frequency measurement

application.

Chapter 6

Edge-to-Edge Measurement

Use edge-to-edge measurement mode if you want to measure the time interval between a specified start edge and a specified stop edge.

The start edge can occur on the rising edge or the falling edge of the Counter 0 Gate signal, and the stop edge can occur on the rising edge or the falling edge of the Counter 0 Gate signal. When the start edge is detected, the counter/timer starts incrementing and continues incrementing until the stop edge is detected. The C/T then stops incrementing until it is enabled to start another measurement. When the operation is complete, you can read the value of the counter. You can count a maximum of 4,294,967,296 events before the counter rolls over to 0 and starts counting again.

You can use edge-to-edge measurement to measure the following characteristics of a signal:

•Pulse width – The amount of time that a signal pulse is in a high or a low state, or the amount of time between a rising edge and a falling edge or between a falling edge and a rising edge. You can calculate the pulse width as follows:

− Pulse width = Number of counts/24 MHz

•Period – The time between two occurrences of the same edge (rising edge to rising edge, or falling edge to falling edge). You can calculate the period as follows:

− Period = 1/Frequency

− Period = Number of counts/24 MHz

• Frequency – The number of periods per second. You can calculate the frequency as follows:

− Frequency = 24 MHz/Number of Counts

Using software, specify the counter/timer mode as measure, the C/T clock source as internal, the start edge as rising or falling gate, and the stop edge as rising or falling gate.

Make sure that the signals are wired appropriately. Refer to

Chapter 4 for an example of connecting an edge-to-edge

measurement application.

Rate Generation

Use rate generation mode to generate a continuous pulse output signal from Counter 0 Out; this mode is sometimes referred to as continuous pulse output or pulse train output.

Principles of Operation

The pulse output operation is enabled whenever the Counter 0 Gate signal is active (high level, low level, or software gate). While the pulse output operation is enabled, the counter outputs a high-to-low going pulse with a pulse width of 50% continuously. As soon as the operation is disabled, rate generation stops.

The frequency of the output is determined by the C/T clock source (either internal or external) and the clock divider used. You can generate an output signal from Counter 0 Out with a frequency of 15 Hz to 12 MHz.

To specify rate generation mode, use software to specify the counter/timer mode as rate, the C/T clock source as either internal or external, the clock divider (2 to 65536), and the active gate type (high-level or software gate). Refer to page 93 for more information about gate types.

Make sure that the signals are wired appropriately. Refer to

Chapter 4 for an example of connecting a rate generation application.

Chapter 6

Supported Device Driver

Capabilities