Data Translation DT7837 User Manual

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UM-26000-A
DT7837 User’s Manual

Title Page

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Copyright Page

First Edition March, 2015
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
Copyright © 2015 by Data Translation, Inc.
All rights reserved.
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.
The DT7837 software is based of the Linux open-source development environment which uses the GNU (General Public License). Data Translation example programs may use code from other vendors. This code is for demonstration purposes only. If you want to use this code for commercial purposes, you must ensure that you resolve any licensing issues with the appropriate parties.
Data Translation® is a registered trademark of Data Translation, Inc.
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

Table of Contents
About this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Intended Audience. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
How this Manual is Organized . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Conventions Used in this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Related Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Where To Get Help. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Chapter 1: Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Hardware Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Board Layout Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Supported Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Supported Accessories. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Getting Started Procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Chapter 2: Principles of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
ARM Block. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
ARM Processor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Embedded NAND Flash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
EEPROM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Micro SD Card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
USB Device (Client) Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
USB Host Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Serial Port 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Serial Port 1 / I2C2 Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
SPI Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
GPMC Bus Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Additional Signals Used on Processor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Digital Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Analog Input Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Analog Input Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Input Ranges and Gains. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
IEPE Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Input Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Continuous Sampling Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Input Triggers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Input Clock Source and Sampling Frequency. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Data Format and Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
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Error Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Tachometer Input Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
General-Purpose Counter/Timer Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
C/T Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
C/T Clock Input Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Gate Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Pulse Output Period, Pulse Width, and Polarity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Counter/Timer Operation Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Event Counting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Rate Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Non-Repeatable One-Shot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Idle Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Measure Counter Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Digital I/O Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Digital I/O Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Operation Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Triggering Acquisition on Multiple Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Chapter 3: Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
If Your Module Needs Factory Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Chapter 4: Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Using the Calibration Utility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Calibrating the Analog Input Subsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Warming up the Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Connecting a Precision Voltage Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Using the Auto-Calibration Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Using the Manual Calibration Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Restoring Factory-Calibration Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Appendix A: Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Analog Input Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Digital Input Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Digital Output Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Tachometer Input Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Measure Counter Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
General-Purpose Counter/Timer Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Trigger Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Master Oscillator Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Power, Physical, and Environmental Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
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Regulatory Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Connector Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
External Power Supply Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Appendix B: Connector Pin Assignments and LED Status Indicators . . . . . . . . . . 75
Analog Input Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Digital Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
USB Device (Client) Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
USB Host Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Ethernet Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Micro SD Card Connector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
External +5 V Power Connector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Serial Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Serial Port 0 (UART 0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
SPI Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
Serial Port 1 / I
2
C2 Connector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
I/O Block Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
STP26 Screw Terminal Panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
LED Status Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Contents
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
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Contents
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The first part of this manual describes how to install and set up your DT7837 module and verify that your module is working properly.
The second part of this manual describes the features of the DT7837 module and how to program the DT7837 module using Linux system calls. Troubleshooting information is also provided.

Intended Audience

This document is intended for engineers, scientists, technicians, or others responsible for using and/or programming a DT7837 module for data acquisition operations in the Linux 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

This manual is organized as follows:
Chapter 1, “Overview,” describes the major features of the DT7837 module, as well as the supported software and accessories for the module.

About this Manual

Chapter 2, “Principles of Operation,” describes all of the features of the DT7837 module.
Chapter 3, “Troubleshooting,” provides information that you can use to resolve problems with the DT7837 module should they occur.
Chapter 4, “Calibration,” describes how to calibrate the analog circuitry of the DT7837 module.
Appendix A, “Specifications,” lists the specifications of the DT7837 module.
Appendix B, “Connector Pin Assignments and LED Status Indicators,” lists the pin assignments of the connectors on the DT7837 module, and describes the LED status indicators on the DT7837 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.
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About this Manual

Related Information

Where To Get Help

Refer to the following documents, which can be found on the DT7837 web page on our website (http://www.datatranslation.com/products/dataacquisition/embedded/DT7837/) for more information on using the DT7837 module:
DT7837 Getting Started help file
• DT7837 File I/O Programming Manual
Refer to your Linux documentation for more information about Linux and Texas Instruments documentation for more information on the TI Sitara AM3352, 1 GHz, ARM® Cortex-A8 processor.
Should you run into problems installing or using a DT7837 module, the Data Translation Technical Support Department is available to provide technical assistance. Refer to Chapter 4 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).
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1

Overview

Hardware Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Supported Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Supported Accessories. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Getting Started Procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
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Chapter 1

Hardware Features

The DT7837 module is an open-source Linux computing platform with a high-accuracy, dynamic signal analyzer front-end, making it ideal for embedded applications that require noise, vibration, and acoustic measurements.
The module is composed of two boards (the bottom board contains the ARM block and the top board contains the I/O block) that connect together, as show in Figure 1. Users can embed the module into their own enclosure and/or system, as needed.
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Figure 1: DT7837 Module
The key features of the DT7837 module are as follows:
• Open-source computing platform featuring a TI Sitara AM3352, 1 GHz, ARM® Cortex-A8 processor.
• Linux distribution consisting of a Linux kernel, bootloader, and file system with a DT7837 device driver, USB device (client) driver, and USB host driver.
• Ethernet 10/100 Mbps connectivity to a host computer.
• USB 2.0 full-speed connectivity to a host computer.
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• USB 2.0 host connection to external devices, such as a mouse, keyboard, or external storage devices.
• Analog input subsystem:
Four, single-ended analog input channels available through SMA connectors.
Four simultaneous sampling, Delta-Sigma, 24-bit analog-to-digital converters (ADCs).
Support for IEPE (Integrated Electronic Piezoelectric) inputs, including use of a 4 mA
current source with 20 V compliance voltage for AC or DC coupling.
Programmable throughput rate from 195.3125 Samples/s to 105.469 kSamples/s.
Input range of ±10 V with software-selectable gains of 1 and 10 for an effective input
range of ±10 V and ±1 V.
Continuous acquisition from multiple analog input channels simultaneously.
Supports the ability to return the value of the tachometer, general-purpose
counter/timer, measure counter, and/or digital input port in the analog input data stream, allowing you to measure a variety of signals synchronously with analog input measurements.
Software-programmable trigger source (software trigger, external trigger, or threshold
trigger using any analog input channel) to start acquisition.
Overview
Accounts for analog input group delay in hardware and allows user-specified trigger
delay to account for analog output group delay.
• Up to eight, TTL digital input lines using the eight general-purpose inputs. You can read the digital input port directly or you can return the value of the digital input port in the input data stream.
• Up to eight, TTL digital output lines using the eight general-purpose outputs. You can write a value to the digital output port directly.
• One, 32-bit, general-purpose counter/timer for performing event counting, rate generation, and non-repeatable one-shot operations. You can use two general-purpose input signals for the C/T clock and gate inputs and one general-purpose output signal for the C/T clock output. You can read the value of the counter/timer directly or through the input data stream.
• One tachometer input signal. The value of the tachometer input signal can be returned in the input stream.
• One phase/measure counter. You can program the edge that starts the measurement and the edge that stops the measurement. Many edge types are supported. The data from the measure counter can be returned in the input stream.
• 2 GB embedded NAND flash memory that contains the Linux kernel, bootloader, and file system; this memory can also be used to store user files and data
• 512 MB SDRAM (DDR3) memory
• 8 kBytes EEPROM
• Micro SD connector supports micro SD cards, which can be used as a boot source for general-purpose file and data storage
• 3.3 V UART, I2C, and an SPI (Serial Peripheral Interface) interfaces for embedded connectivity.
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Chapter 1
• Serial debug port.
• External power connectors (4-pin DIN or 3-pin Phoenix header) for connecting a +5 VDC power supply.
14
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Board Layout Overview

The DT7837 module consists of an ARM block and a I/O block. Figure 2 shows the layout of the ARM block (the bottom board). Figure 3 shows the layout of the I/O block (the top board).
Overview
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Chapter 1
Digital Connector
(Tachometer, Digital I/O, External Trigger, Counter/Timer)
Power L ED
Ethernet
Connector
USB Host
Port
USB Device (Client) Port
SD Card
+5 V Power
AM3552
Processor
Reset/Boot
Switch
Connector to the
I/O Block
Serial Port 1
(J14)
Serial Port 0
(J13)
SPI
Port
(J12)
Grounding
Stud
16
Figure 2: Layout of the ARM Block of the DT7837 Module
Page 17
Overview
Output Trigger
LED (bottom)
Input Trigger LED
(top)
Analog Output Connector
(analog output currently not
supported in software)
Analog Input Connectors
Figure 3: Layout of the I/O Block of the DT7837 Module
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Chapter 1

Supported Software

The following software is available for use with the DT7837 module:
DT7837 File I/O Commands – A set of commands in Linux user space for opening a subsystem or stream, configuring a subsystem or stream, acquiring data in the input stream, reading or updating the digital I/O port, and/or writing values to the calibration potentiometers. Numerous example programs are provided to illustrate how to use these commands. Refer to the DT7837 File I/O Programming Manual for more information.
DT7837 Kernel Device Driver – The device driver resides in the Linux kernel and is responsible for performing the functions defined by the DT7837 file I/O commands on the DT7837 module.
DT7837 Calibration Utility – This utility, described in Chapter 4, allows you to calibrate the analog circuitry of the DT7837 module.
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Supported Accessories

The following optional accessories are available for a DT7837 module:
STP26 screw terminal panel – This screw terminal panel accepts tachometer, digital input, C/T gate input, and C/T clock input signals from the Digital connector on the DT7837 module and provides digital output and C/T clock output signals from the Digital connector on the module.
The 26-pin, 36-inch, EP406 cable is included with the STP26 screw terminal panel. The cable allows you to attach the STP26 screw terminal panel to the Digital connector on a DT7837 module.
Figure 4 shows the STP26 and EP406 cable.
Overview
Figure 4: STP26 Screw Terminal Panel and EP406 Cable
• EP405 USB to Serial TTL Debug Cable – This 3Mbaud, 1.8 m cable, shown in Figure 5, connects the USB port of the host computer to serial UART connector J13 on the DT7837, allowing you to debug the DT7837 using a terminal interface.
Figure 5: EP405 USB to Serial TTL Debug Cable
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Chapter 1
EP361 External Power Supply – This +5 VDC optional power supply and cable, shown in
Figure 6, connects to the DIN power connector on the DT7837 module and to the wall
power outlet.
Figure 6: EP361 +5 VDC External Power Supply
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Getting Started Procedure

Refer to the DT7837 Getting Started help file on our web site (http://www.datatranslation.com/products/dataacquisition/embedded/DT7837/) for getting started information
Overview
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Chapter 1
22
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2

Principles of Operation

Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Analog Input Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Tachometer Input Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
General-Purpose Counter/Timer Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Measure Counter Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Digital I/O Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Triggering Acquisition on Multiple Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
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Chapter 2
Serial UART
Ethernet
10/100
USB 2.0
Host
USB 2.0
Client
SD Card
DT7837 Block Diagram
Four 24-Bit
A/D Inputs
I/O B loc k
DRAM
512 MB DDR 3
TI
AM335x
ARM Cortex-A8
Clock G e n e rato rs
Voltage Regulators
ARM Block
GPMC
Bus
NAND Flash 2GB
Expansion
Bus
26-Pin D i gita l
Connector
IEPE Inp u ts
GP IO Sign a ls
(8 DI, 8 DO,
Measure Counter,
Counter/Timer,
Ext. T rig g e r In p u t)
Tachometer
FPGA
FIFOs
Power Supply
+5 VDC
24-Bit
D/A Output
Stim ulus
Waveform
Output*
*Currently, not supported in software.

Block Diagram

The DT7837 is an open-source Linux computing platform with a high-accuracy, dynamic signal analyzer front-end.
The DT7837 consists of two boards. The bottom board is the ARM block, which includes the ARM processor, PC and embedded connectivity options, and memory, as well as the digital I/O, counter/timer, measure counter, and tachometer circuitry.
The top board is the I/O block, which includes four 24-bit IEPE analog inputs and one 24-bit stimulus analog output.
Note: The analog output circuitry is currently not supported in software.
Figure 7 shows a block diagram of the DT7837 module.
24
Figure 7: Block Diagram of the DT7837 Module
Page 25

ARM Block

The ARM block of the DT7837 module uses the TI Sitara AM3352 processor and its associated peripherals to provide an open-source, single-board computer. The AM3352 supports many different interfaces, many of which are shared on the configurable I/O pins. In addition to the AM3352, the DT7837 module uses an embedded NAND flash and an FPGA.
This section describes the features of the ARM block in more detail.

ARM Processor

The AM3352 is based on the ARM Cortex-8 32-bit processor and is configured to run at 600 MHz.
Refer to the following web site for more information on this processor: http://www.ti.com/product/am3352

Memory

Principles of Operation
A 512 MB, DDR3, SDRAM memory device is connected to the AM3352 processor through a dedicated DDR (Double Data Rate) memory interface.

Embedded NAND Flash

A 2 GB embedded NAND flash device is connected to the AM3352 processor through the 16-bit GPMC (General Purpose Memory Controller) bus, and can be accessed at the CS0 address space. The flash memory contains the Linux kernel, bootloader, and the file system.
You can also use the flash memory for general-purpose data and file storage as well as for input data and waveform storage.

EEPROM

An 8 kByte EEPROM device is connected to the I2C0, 2-wire, serial interface of the AM3352 processor. The EEPROM stores information about the device, including the calibration information.
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Micro SD Card

A micro SD card slot is provided to support optional high-speed (up to 24 MB/s) micro SD cards. Micro SD cards (not provided with the module) communicate with the AM3352 processor using the MMC0 port in the 4-bit interface mode.
You can use a micro SD card as a boot source or for general-purpose file and data storage.

USB Device (Client) Port

The DT7837 module provides a USB 2.0 device (client) port on a type B receptacle. The device port connects to the USB port 0 controller of the AM3352 processor.
When connected to a host computer through this USB port, the host computer can identify the DT7837 module and load the appropriate drivers through the enumeration process.

USB Host Port

The DT7837 provides a high-speed USB 2.0 host port on a type A receptacle. The host port connects to the USB port 1 controller of the AM3352 processor. The USB host port supports any USB device, provided that the required software is installed on the Linux operating system.
If desired, you can connect USB devices, such as a keyboard, mouse, memory stick, or hub to this port.

Serial Port 0

Serial port 0 is a 3.3 V TTL serial interface provided on a 6-pin header. This port supports transmit and receive signals (no handshaking), and connects to the UART 0 interface of the AM3552 processor.
This port is particularly useful when you are debugging your applications. To use this port, use the EP405 USB to serial TTL adapter cable.

Serial Port 1 / I2C2 Port

Serial port 1 and the I2C2 port are provided on the same 6-pin header.
Serial port 1 is a 3.3 V TTL serial interface that supports transmit and receive signals, and connects to the UART1 interface of the AM3552 processor.
The bidirectional I provided for embedded connectivity. It is possible to reconfigure the pins of the I interface as the remaining UART 1 pins to provide the full functionality of serial port 1.
2
C2 port connects to the I2C port 2 interface of the AM3552 processor and is
2
C port 2
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SPI Port

The SPI (Serial Peripheral Interface) is provided on an additional 6-pin header for embedded connectivity. This port connects to the SPI port 1 interface of the AM3552 processor.

GPMC Bus Interface

A 16-bit address/data multiplexed bus interface is supplied by the processor. In addition to the NAND flash, this bus also supports the FPGA. All control registers for the DT7837 are accessible in the CS1 address space. The CS3 address space provides access to the input FIFO.

Additional Signals Used on Processor

The following are additional pins on the processor that are connected for use on the DT7837 module:
• XDMAEvent0 – Configured, but not used
• XDMAEvent1 – Used for an analog output DMA event (currently not supported)
• XDMAEvent2 – Used for an analog input DMA event
Principles of Operation
• GPIO1_20 – Configured for a DMA event, but not used
• GPIO1_25 – Configured as an interrupt, but not used
• GPIO1_26 – Configured as an interrupt, but not used
• GPIO1_27 – Configured as an interrupt, but not used
• GPIO3_20 – Configured as an interrupt, but not used

Digital Connector

The Digital connector provides access to the tachometer input and GPIO (General Purpose Input and Output) signals of the DT7837 module. Refer to page 77 for the pin assignments of this connector.
Using software, you can specify a general-purpose input signal as the signal source for the following destinations:
• Digital input (the default signal for each general-purpose input pin)
• External A/D trigger input
• External D/A trigger input
• Gate input for the general-purpose counter/timer (C/T 0)
• Clock input for the general-purpose counter/timer (C/T 0)
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Using software, you can specify a general-purpose (general-purpose) output signal as the signal source for one of these destinations:
• Digital output (the default signal for each general-purpose output pin)
• Clock output for the general-purpose counter/timer (C/T 0)
Note that a single general-purpose input may drive several destinations at the same time. However, a single general-purpose output can have only one driving source.
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Analog Input Features

This section describes the following features of analog input (A/D) subsystem on the DT7837 module:
• Analog input channels, described on this page
• Input ranges and gains, described on this page
• IEPE functions, described on page 30
• Input resolution, described on page 30
• Continuous sampling mode, described on page 30
• Input triggers, described on page 31
• Input sample clock source and sampling frequency, described on page 32
• Data format and transfer, described on page 33
• Error conditions, described on page 33

Analog Input Channels

Principles of Operation
The DT7837 module provides four analog input channels (channels 0 to 3). These are single-ended channels; you can connect IEPE sensors to these inputs, if desired; refer to page
30 for more information on IEPE functions.
Note: To maintain simultaneous operation, all analog input connections on the DT7837 module must have the same lead lengths.
The DT7837 module uses four, Delta-Sigma, 24-bit ADCs that provide anti-aliasing filters based on the clock rate. These filters remove aliasing, which is a condition where high frequency input components erroneously appear as lower frequencies after sampling.
Using software, you can specify which analog input channels to sample by specifying bits 0 to 3 in the channel mask for the input stream.

Input Ranges and Gains

The DT7837 module provides an input range of ±10 V and software-selectable gains of 1 and
10. This provides effective input ranges of ±10 V (when the gain is 1) and ±1 V (when the gain is 10).
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Chapter 2

IEPE Functions

Applications that require accelerometer, vibration, noise, or sonar measurements often use IEPE sensors. IEPE conditioning is built-in to the analog input circuitry of the DT7837 module. The modules support the following software-programmable IEPE functions for each analog input channel:
• Excitation current source – The DT7837 module provides an internal excitation current source of 4 mA. You can turn the internal excitation current source on or off using software.
• Coupling type – You can select whether AC coupling or DC coupling is used.
DT7837 modules provide +20 V compliance voltage.
Note: If you enable the use of the internal excitation current source, it is recommended that you choose AC coupling.

Input Resolution

The resolution of the analog input channels is fixed at 24 bits; you cannot specify the resolution in software.

Continuous Sampling Mode

The DT7837 module supports continuous sampling mode on the input stream. This is an asynchronous I/O operation that is non-blocking so that your application can perform other operations while acquisition is being performed.
In continuous sampling mode, you can acquire data from the following channels in the input data stream: analog input channels 0 to 3, the tachometer input, the general-purpose counter/timer, the measure counter, and the digital input port. In software, you specify the channel mask for the input stream to determine which channels to sample. The bits of the channel mask are as follows:
• Channels (bits) 0 to 3 – Analog input channels 0 to 3
• Channel (bit) 4 – Tachometer; refer to page 34 for more information
• Channel (bit) 5 – Counter/timer 0; refer to page 36 for more information
• Channel (bit) 6 – Measure counter; refer to page 43 for more information
• Channel (bit) 7 – Digital input port; refer to page 47 for more information
30
The trigger that starts acquisition for the channels in the input stream can be any of the supported start trigger sources. Refer to page 31 for more information about the start trigger sources. However, the input stream of the module must be armed (using software) before the module can detect the trigger condition.
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Principles of Operation
Chan 0
Chan 1
Chan 7
Input
Sample
Clock
Chan 0
Chan 1
Chan 7
Chan 0
Chan 1
Chan 7
Chan 0
Chan 1
Chan 7
Start Trigger occurs
Pre-trigger data acquired
Chan 0
Chan 1
Chan 7
Chan 0
Chan 1
Chan 7
If a software trigger is specified as the start trigger, acquisition starts immediately when the software start command is executed. Otherwise, acquisition begins when the specified trigger signal is detected. When it detects the specified start trigger, the module simultaneously acquires data from all of the channels in specified in the input stream. Acquisition repeats continuously until you stop the operation. The conversion rate is determined by the sampling frequency; refer to page 32 for more information.
When you stop the operation using software, the DMA engine stops and no further data is collected. It is the programmer’s responsibility to clean up all inprocess control block resources. To restart the operation, the input stream of the module must be armed and started again.
Figure 8 illustrates continuous acquisition mode using three channels: analog input channels 0
and 1 and the digital input port. When the start trigger is detected, samples from the specified channels are acquired continuously.

Input Triggers

Figure 8: Continuous Sampling Mode on the DT7837 Module
A trigger is an event that occurs based on a specified set of conditions. For continuous sampling mode of the channels in the input data stream, described on page 30, you must specify a start trigger to start acquisition.
The DT7837 module supports the following sources for the start trigger; you configure the trigger source and its parameters using software:
Software trigger – A software trigger event occurs when you start the analog input operation (the computer issues a write to the module to begin conversions). Using software, specify the start trigger source as a software trigger.
External digital (TTL) trigger – An external digital (TTL) trigger event occurs when the module detects a rising- or falling-edge transition on the signal connected to a general-purpose input pin on the Digital connector. (Refer to page 27 for more the pin descriptions of the Digital connector.) You can specify which edge is active using software.
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Threshold trigger – The start trigger event occurs when the signal attached to a specified analog input channel rises above or falls below a user-specified threshold value. Using software, you specify the following parameters:
Edge – Specify a rising-edge threshold trigger if you want to trigger when the signal
rises above a threshold level, or a falling-edge threshold trigger if you want to trigger when the signal falls below a threshold level.
Threshold channel – Specify any one of the analog input channels as the threshold
input channel.
Threshold level – Specify a value between ±10 V for a gain of 1 or ±1 V for a gain of 10
as the threshold level. Note that in software, this value must be entered as counts.
To convert raw counts to volts, use the following formulas:
Gain of 1
Gain of 10
Note: The DT7837 driver sets the threshold level as close as possible to the value that you specify. However, the value that you specify may not be the actual value that is set. You can return the actual threshold level that was set using software.
: volts = ((2.0f * 10.0f * counts)/(1<<24) – 10.0f)
: volts = ((2.0f * counts)/(1<<24) – 1.0f)

Input Clock Source and Sampling Frequency

The DT7837 module supports an internal A/D clock, which is derived from the 48 MHz reference clock. The reference clock is generated from the onboard oscillator.
Using software, you specify the frequency at which to pace input operations. The sampling frequency can range from 195.3125 Hz to 105.469 kHz.
Note: 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 kHz signal, specify a sampling frequency of at least 40 kHz to avoid aliasing.
32
The DT7837 driver sets the sampling frequency as close as possible to the value that you specify. However, the value that you specify may not be the actual value that is set. You can return the actual sampling frequency that was set using software.
Once the sample clock is started, the module requires 39 conversions before the first A/D sample is valid. The valid sample is aligned with the start trigger.
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Note: After changing the A/D master clock, wait a few milliseconds for the master clock to settle before calibrating the module or performing an acquisition.
The DT7837 module has two power modes: low power mode and high power mode. Low power mode is used when you specify a sampling frequency less than 52.734 kHz. High power mode is used when you specify a sampling frequency greater than or equal to
52.734 kHz. If you change the power mode from low to high power or from high power to
low power, and then configure the device, the module is self-calibrated. You may notice that it takes time after the device is configured to complete the calibration process.

Data Format and Transfer

The DT7837 has an input FIFO of 2 kSamples (8 kBytes). Each sample of the DT7837 is a 32-bit value.
The DT7837 module uses offset binary data encoding, where 000000 represents negative full-scale, and FFFFFFh represents positive full-scale. Use software to specify the data encoding as binary. The ADC outputs FFFFFFh for above-range signals, and 000000 for below-range signals.
Principles of Operation

Error Conditions

The DT7837 module will detect an overrun error if the user buffers are not being sent to the module fast enough, and the A/D converters run out of user buffers to fill. To avoid this error, try one or more of the following:
• Reduce the clock rate of the A/D
• Increase the size of the buffers
• Increase the number of buffers
• Close any other applications that are running
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Tachometer Input Features

You can connect a tachometer signal with a range of ±30 V to pin 23 of the Digital connector. (Refer to page 27 for the pin descriptions of the Digital connector.) The tachometer input accepts signals with a maximum frequency of 1 MHz and a minimum pulse width of 0.4 μs. The threshold voltage is fixed at +2 V with 0.5 V of hysteresis.
To read the value of tachometer in the input stream, specify bit 4 in the channel mask for the input stream.
You can measure the frequency or period of the tachometer input signal to calculate the rotation speed for high-level (±30 V) tachometer input signals. An internal 12 MHz counter is used for the measurement, yielding a resolution of 83 ns (1/12 MHz).
You can read the number of counts between two consecutive starting edges of the tachometer input signal by including channel 4 for the DT7837 in the analog input channel list. The starting edge is programmable (either rising or falling).
Using software, you can also specify a flag (called Stale) that indicates whether or not the data is new. If the Stale flag is set as Used (the default value), the most significant bit (MSB) of the value is set to 0 to indicate new data; reading the value before the measurement is complete returns an MSB of 1. If the Stale flag is set to Not Used, the MSB is always set to 0.
When the input operation is started, the internal 12 MHz counter starts incrementing when it detects the first starting edge of the tachometer input and stops incrementing when it detects the next starting edge; at that point, the counter stores the count. The stored count is maintained until it is read as part of the input data stream or until a new count is stored. The next tachometer measurement operation is started automatically.
If the sample rate of the input subsystem is faster than the tachometer input frequency, then the stored count retains the current value when the count is read by the input subsystem. The operation of the Stale flag in this case is described as follows:
• If another input subsystem sample occurs before another measure completes and the Stale flag is enabled, then the Stale flag is set and the stale measure count is written into the input data stream.
• If another input subsystem sample occurs before another measure completes and the Stale flag is disabled, then the Stale flag is not set and the stale measure count is written into the input data stream.
If the input sample rate is slower than the tachometer input frequency, then as each period measurement completes, a new count value is stored. When the input subsystem sample occurs, the most recently stored measure count is written into the input data stream.
A data pipeline is used in the hardware to compensate for the A/D group delay and
synchronizes the value of the tachometer input with the analog input measurements so that
all measurements are correlated in time. The tachometer input is treated like any other channel in the analog input channel list; therefore, all the triggering and conversion modes supported for analog input channels are supported for the tachometer input.
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Principles of Operation
When you read the value of the tachometer input as part of the analog input data stream, you might see results similar to the following:
Table 1: An Example of Reading the Tachometer Input as Part of the Analog Input Data Stream
Tachomete r
Time A/D Value
10 5002 0 Operation started, but is not complete
20 5004 0 Operation not complete
30 5003 0 Operation not complete
40 5002 12373 Operation complete
50 5000 12373 Next operation started, but is not complete
60 5002 12373 Operation not complete
70 5004 12373 Operation not complete
80 5003 14503 Operation complete
90 5002 14503 Next operation started, but is not complete
Input Value
Status of Operation
Using the count that is returned from the tachometer input, you can determine the following:
• Frequency of a signal pulse (the number of periods per second). You can calculate the frequency as follows:
Frequency = 12 MHz/(Number of counts – 1)
where 12 MHz is the internal counter/timer clock frequency
For example, if the count is 21, the measured frequency is 600 kHz (12 MHz/20).
• Period of a signal pulse. You can calculate the period as follows:
Period = 1/Frequency
Period = (Number of counts – 1)/12 MHz
where 12 MHz is the internal counter/timer clock frequency
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Chapter 2
Clock Input SIgnal
(internal or external)
Counter
Gate Input Signal
(software or external
input)
Pulse Output Signal

General-Purpose 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 37
• Gate types, described on page 37
• Pulse output period and duty cycle, described on page 38
• C/T operation modes, described on page 39

C/T Channels

DT7837 modules provide one 32-bit, general-purpose counter/timer (C/T 0). As shown in
Figure 9, the counter/timer accepts a clock input and gate input signal and outputs a pulse
(clock output signal).
Figure 9: Counter/Timer Channel
Using software, you define general-purpose I/O pins on the Digital connector for the external C/T clock input, external C/T gate input, and C/T clock output signals.
To read the value of C/T 0 in the input stream, specify bit 5 in the channel mask of the input stream.
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C/T Clock Input Sources

The following clock input sources are available for the general-purpose counter/timer; you select the clock source through software:
Internal C/T clock – The internal C/T clock uses a 48 MHz time base. This clock source is typically used for one-shot, repetitive one-shot, and rate generation operations.
External C/T clock – An external C/T clock is useful when you want to pace counter/timer operations at rates not available with the internal C/T clock or if you want to pace at uneven intervals. The frequency of the external C/T clock can range from
0.0112 Hz to 10 MHz.
This clock source is typically used for event counting and rate generation operations.
Using software, specify one of the general-purpose input pins (1 to 8) of the Digital connector on the DT7837 module as the external C/T clock input. Then, physically connect the external clock signal to the selected pin. (Refer to page 27 for the pin descriptions of the Digital connector.) Counter/timer operations start on the rising edge of the clock input signal.
Note: If you specify a counter/timer in the input stream, the A/D clock determines how often you want to read the counter value. Refer to page 32 for more information about the A/D sample clock.
Principles of Operation

Gate Types

The edge or level of the counter gate signal determines when a counter/timer operation is enabled.
Unless you are using a software gate (no gate), define one of the general-purpose input pins of the Digital connector on the DT7837 module as the external C/T gate input using software. Then, physically connect the external gate signal to the selected pin. (Refer to page 27 for the pin descriptions of the Digital connector.)
DT7837 modules provide the following gate types; you select the gate type using software:
None – A software start command enables any counter/timer operation immediately after execution. (No general-purpose input signal is required if a gate type of None is selected.)
Low external gate input – Specifies a logic low or falling edge gate type. For event counting and rate generation mode, the operation is enabled when the counter’s gate signal is low and is disabled when the counter’s gate signal is high. For one-shot mode or repetitive one-shot mode, the operation is enabled when the counter’s gate signal goes from a high to a low transition and is disabled when the counter ’s gate signal goes from a low to a high transition.
You specify one of the general-purpose input pins (1 to 8) of the Digital connector on the DT7837 module as the external C/T gate input. Ensure that you physically connect the external gate signal to the selected pin. (Refer to page 27 for the pin descriptions of the Digital connector.)
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Total Pulse Period = 10
With an external C/T input clock of
10000 Hz and a period of 10, the
output signal is 1000 Hz.
Active Pulse Width = 2 for 20% duty cycle
low pulse
high pulse
High external gate input – Specifies a logic high or rising edge gate type. For event counting and rate generation mode, the operation is enabled when the counter’s gate signal is high and is disabled when the counter’s gate signal is low. For one-shot mode or repetitive one-shot mode, the operation is enabled when the counter’s gate signal goes from a low to a high transition and is disabled when the counter ’s gate signal goes from a high to a low transition.
You specify one of the general-purpose input pins (1 to 8) of the Digital connector on the DT7837 module as the external C/T gate input. Ensure that you physically connect the external gate signal to the selected pin. (Refer to page 27 for the pin descriptions of the Digital connector.)

Pulse Output Period, Pulse Width, and Polarity

If you want to perform a C/T output operation, define one of the general-purpose output pins (11 to 18) of the Digital connector on the DT7837 module as the external C/T output signal using software. Then, connect the external C/T output signal to the selected pin. (Refer to
page 27 for the pin descriptions of the Digital connector.)
For the DT7837 module, you can program the polarity of the output pulse (active high or active low). For an active high pulse, the high portion of the total pulse output period is the active portion of the counter/timer pulse output signal. For an active low pulse, the low portion of the total pulse output period is the active portion of the counter/timer pulse output signal.
Using software, you can specify the number of input clock cycles that are used to create one period of the counter clock output signal. You can also specify the number of input clock cycles used to create the active pulse width (or duty cycle) of the C/T output signal.
For example, if you are using an external C/T clock running at 10000 Hz as the input clock source of the counter/timer, and you want to generate a output signal of 1000 Hz with a 20% duty cycle, specify a period of 10 (10000 Hz divided by 10 is 1000 Hz) and a pulse width of 2 (the period of 10 multiplied by 20%). This is illustrated in Figure 10.
Figure 10: Example of a Pulse Output
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Note: If you are using an internal C/T clock input source, you can output pulses using a maximum frequency of 24 MHz. Note, however, that the integrity of the signal degrades at frequencies greater than 10 MHz.
If you are using an external C/T clock input source, you can output pulses using a maximum frequency of 5 MHz.

Counter/Timer Operation Modes

The general-purpose counter/timer on the DT7837 module supports the following counter/timer operation modes:
• Event counting
• Rate generation
• Non-repeatable one-shot
•Idle
Principles of Operation
The following subsections describe these modes in more detail.
Event Counting
Use event counting mode if you want to count the number of rising edges that occur on the counter’s clock input when the counter’s gate signal is active (low-level or high-level).
You can count a maximum of 4,294,967,296 events before the counter rolls over to 0 and starts counting again.
Using software, you must specify the following parameters for the event counting operation:
• Active gate type (external low level or external high level). Refer to page 37 for more information about the supported gate types.
• The general-purpose input pin to use for the external gate signal. Ensure that you physically connect the gate signal to this input pin. Refer to page 27 for the pin descriptions of the Digital connector.
• The C/T clock source (internal or external). Note that in event counting mode, the external C/T clock is more useful than an internal C/T clock; refer to page 37 for more information about the C/T clock sources.
• The general-purpose input pin to use for the external C/T clock input. Ensure that you physically connect the clock input signal to this input pin. Refer to page 27 for the pin descriptions of the Digital connector.
Refer to page 39 for an example of connecting an event counting application.
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Chapter 2
Rate Generation
Use rate generation mode to generate a continuous pulse output signal from the counter ’s output signal. You can use this pulse output signal as an external clock to pace other operations, such as an analog input or other counter/timer operations.
The pulse output operation is enabled whenever the counter’s gate signal is at the specified level. While the pulse output operation is enabled, the counter outputs a pulse of the specified type and frequency continuously. As soon as the operation is disabled, rate generation stops.
You can output pulses using a maximum frequency of 24 MHz (if using the internal C/T clock) or 5 MHz (if using the external C/T clock).
Note: The integrity of the signal degrades at frequencies greater than 10 MHz.
Using software, you must specify the following parameters for the rate generation operation:
• Active gate type (external low level or external high level). Refer to page 37 for more information about the supported gate types.
• The general-purpose input pin to use for the external gate signal. Ensure that you physically connect the gate signal to this input pin. Refer to page 27 for the pin descriptions of the Digital connector.
• The C/T clock source (internal or external). Refer to page 37 for more information about the C/T clock sources.
• If you are using an external C/T clock source, the general-purpose input pin to use for the external C/T clock input. Ensure that you physically connect the clock input signal to this input pin. Refer to page 27 for the pin descriptions of the Digital connector.
• The period of the output pulse. Refer to page 38 for more information about the period of the output pulse.
• The pulse width (duty cycle) of the active pulse. Refer to page 38 for more information about the pulse width of the output pulse.
• The general-purpose output signal to use for the C/T clock output signal. Ensure that you physically connect the C/T output signal to this output pin. Refer to page 27 for the pin descriptions of the Digital connector.
• The polarity of the output signal (active high or active low). Refer to page 38 for more information on the polarity of the output pulse.
Refer to page 40 for an example of connecting a rate generation application.
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Principles of Operation
Gate Input (High)
Output Pulses*
Gate Signal is Ignored
*You can determine period, pulse width, and polarity of the output pulse using software.
Non-Repeatable One-Shot
Use non-repeatable one-shot mode to generate a single output pulse from the counter whenever the specified edge is detected on the counter’s gate signal (after the pulse period from the previous output pulse expires). Any gate signals that occur while the pulse is being output are not detected by the module, as shown in Figure 11. The module continues to output a pulse when the specified gate edge is detected until you stop the operation. You can use this mode to clean up a poor clock input signal by changing its pulse width, and then outputting it.
Figure 11: Non-Repeatable One-Shot Mode
Using software, you must specify the following parameters for the non-repeatable one-shot operation:
• Active gate type that enables the operation. Refer to page 37 for more information about the supported gate types.
• The general-purpose input pin to use for the external gate signal. Ensure that you physically connect the gate signal to this input pin. Refer to page 27 for the pin descriptions of the Digital connector.
• The C/T clock source (internal or external) that generates the pulse. Note that in one-shot mode, the internal C/T clock is more useful than an external C/T clock; refer to page 37 for more information about the C/T clock sources.
• The general-purpose input pin to use for the external C/T clock input. Ensure that you physically connect the clock input signal to this input pin. Refer to page 27 for the pin descriptions of the Digital connector.
• The period of the output pulse. Refer to page 38 for more information about the period of the output pulse.
• The pulse width (duty cycle) of the active pulse. Refer to page 38 for more information about the pulse width of the output pulse.
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• The general-purpose output signal to use for the C/T clock output signal. Ensure that you physically connect the C/T output signal to this output pin. Refer to page 27 for the pin descriptions of the Digital connector.
• The polarity of the output signal (active high or active low). Refer to page 38 for more information on the polarity of the output pulse.
• Retriggerable setting of 0 for non-repeatable one-shot.
Refer to page 41 for an example of connecting a non-repeatable one-shot application.
Idle Mode
If you use idle mode, the counter no longer drives the clock output signal that is assigned to one of the general-purpose output signals (pins 11 to 18) of the Digital connector.
Note: The value of the counter output signal can also be overwritten by writing to the digital output subsystem.
If you assigned a general-purpose input signal as a counter clock or gate input (or external trigger), you can read the value of the signal as you would any other digital input signal.|
Refer to page 47 for more information on digital I/O operations.
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Measure Counter Features

DT7837 modules provides one measure counter. Using this counter, you can measure the frequency, period, or pulse width of a single signal or the time period between two signals and return the value in the analog input stream. This is useful for correlating the analog input data with digital positional data, measuring the frequency of a signal, or as a tachometer. An internal 48 MHz counter is used for the measurement, yielding a resolution of 20 ns (1/48 MHz).
Using software commands, you can configure the following parameters for the measure counter:
• The signals that start and stop the measurement. Refer to Tab l e 2 for the supported start and stop signals.
Table 2: Possible Start and Stop Signals
Signal Connection Required
A/D conversion complete No connection required.
Principles of Operation
Tachometer input (falling edge or rising edge)
Digital input 0 (falling edge or rising edge)
Digital input 1 (falling edge or rising edge)
Digital input 2 (falling edge or rising edge)
Digital input 3 (falling edge or rising edge)
Digital input 4 (falling edge or rising edge)
Digital input 5 (falling edge or rising edge)
Digital input 6 (falling edge or rising edge)
Connect to Tachometer input.
Connect a digital input, external A/D trigger, C/T clock input, or C/T gate input to general-purpose input 0 (pin 1) of the Digital connector. By default, this is digital input 0.
Connect a digital input, external A/D trigger, C/T clock input, or C/T gate input to general-purpose input 1 (pin 2) of the Digital connector. By default, this is digital input 1.
Connect a digital input, external A/D trigger, C/T clock input, or C/T gate input to general-purpose input 2 (pin 3) of the Digital connector. By default, this is digital input 2.
Connect a digital input, external A/D trigger, C/T clock input, or C/T gate input to general-purpose input 3 (pin 4) of the Digital connector. By default, this is digital input 3.
Connect a digital input, external A/D trigger, C/T clock input, or C/T gate input to general-purpose input 4 (pin 5) of the Digital connector. By default, this is digital input 4.
Connect a digital input, external A/D trigger, C/T clock input, or C/T gate input to general-purpose input 5 (pin 6) of the Digital connector. By default, this is digital input 5.
Connect a digital input, external A/D trigger, C/T clock input, or C/T gate input to general-purpose input 6 (pin 7) of the Digital connector. By default, this is digital input 6.
Digital input 7 (falling edge or rising edge)
Connect a digital input, external A/D trigger, C/T clock input, or C/T gate input to general-purpose input 7 (pin 8) of the Digital connector. By default, this is digital input 7.
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• A flag (called Stale) indicating whether or not the data is new. This flag is used only when the start edge and the stop edge is set to use the same pin and edge.
If the Stale flag is set as Used (the default value), the most significant bit (MSB) of the value is set to 0 to indicate new data; reading the value before the measurement is complete returns an MSB of 1. If the Stale flag is set to Not Used, the MSB is always set to
0.
When the selected start edge is the same as the selected stop edge, the internal 48 MHz counter starts incrementing when it detects the first start edge of the selected input signal and stops incrementing when it detects the selected stop edge (which is the same as the start edge, in this case); at that point, the counter stores and resets the count. The stored count is maintained until it is read as part of the input data stream or until a new count is stored. Since the stop edge is the same as the start edge in this case, the stop edge for the current measurement is the start edge for the next measurement; therefore, no waveform periods are missed. The value of the measure count depends on the input subsystem sample frequency, described as follows:
• If the input subsystem sample frequency is faster than the selected input frequency, then the stored measure count retains the current value when it is read by the input subsystem. The operation of the Stale flag in this case is described as follows:
If another input subsystem sample occurs before another measure completes and the
Stale flag is used, then the Stale flag is set and the stale measure count is written into the input data stream.
If another input subsystem sample occurs before another measure completes and the
Stale flag is not used, then the Stale flag is not set and the stale measure count is written into the input data stream.
• If the input subsystem sample frequency is slower than the selected input frequency, then the new measure count value is stored as each period measurement completes. When an input subsystem sample occurs, then the most recently stored measure count is written into the input data stream.
When the selected start edge is not the same as the selected stop edge, the internal 48 MHz counter starts incrementing when it detects the selected start edge and stops incrementing when it detects the next selected stop edge; at that point, the counter stores and resets the count. The stored count is maintained until it is read as part of the input data stream or until a new count is stored. The value of the measure count depends on the input subsystem sample frequency, described as follows:
• If the input subsystem sample rate is faster than the selected measurement period, then the stored count retains the current value when the count is read by the input subsystem. The operation of the Stale flag in this case is described as follows:
If another input subsystem sample occurs before another measure completes and the
Stale flag is used, then the Stale flag is set and the stale measure count is written into the input data stream.
44
If another input subsystem sample occurs before another measure completes and the
Stale flag is not used, then the Stale flag is not set and the stale measure count is written into the input data stream.
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Principles of Operation
• If the input subsystem sample rate is slower than the selected measurement period, then a new count value is stored as each period measurement completes. When an input subsystem sample occurs, the most recently stored measure count is written into the input data stream.
A data pipeline is used in the hardware to compensate for the A/D group delay and synchronizes the value of the measure counter with the analog input measurements, so that all measurements are correlated in time. The measure counter is treated like any other channel in the analog input channel list; therefore, all the triggering and conversion modes supported for analog input channels are supported for the measure counter.
When you read the value of the measure counter as part of the analog input data stream, you might see results similar to the following:
Table 3: An Example of Reading a Measure Counter as Part of the Analog Input Data Stream
Measure Counter
Time A/D Value
10 5002 0 Operation started, but is not complete
Val ues
Status of Operation
20 5004 0 Operation not complete
30 5003 0 Operation not complete
40 5002 12373 Operation complete
50 5000 12373 Next operation started, but is not complete
60 5002 12373 Operation not complete
70 5004 12373 Operation not complete
80 5003 14503 Operation complete
90 5002 14503 Next operation started, but is not complete
Using the count that is returned from the measure counter, you can determine the following:
• Frequency between the start and stop signals/edges. You can calculate the frequency as follows:
Frequency = 48 MHz/(Number of counts – 1)
where 48 MHz is the internal measure counter frequency
For example, if the count is 201, the measured frequency is 240 kHz (48 MHz/200).
• Period between the start and stop signals/edges. You can calculate the period as follows:
Period = 1/Frequency
Period = (Number of counts – 1)/48 MHz
where 48 MHz is the internal measure counter frequency
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• Pulse width of the start and stop signal/edges (rising to falling edge or falling edge to rising edge). You can calculate the period as follows:
Pulse width = 1/Frequency
Pulse width = (Number of counts – 1)/48 MHz
where 48 MHz is the internal measure counter frequency
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Digital I/O Features

This section describes the following features of digital I/O operations:
• Digital I/O lines
•Operation modes

Digital I/O Lines

DT7837 modules support one digital input port, consisting of up to 8 digital input lines (lines 0 to 7) and one digital output port, consisting of up to 8 digital output lines (lines 0 to 7). The resolution is fixed at 8 bits.
By default, general-purpose input pins 1 to 8 of the Digital connector on the DT7837 module correspond to digital input signals 0 to 7. Similarly, general-purpose output pins 11 to 18 of the Digital connector on the DT7837 module correspond to digital output signals 0 to 7.
Note: If you assigned a general-purpose input signal as a counter clock or gate input or as an external trigger, you can read the value of the signal as you would any other digital input signal, if desired.
Principles of Operation
If you want to write a value to a specific digital output line, ensure that the corresponding pin of the Digital connector is not configured for another use (such as the output of the counter/timer) or you could corrupt the signal on the pin.
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 and a high value (1) is read from each of the digital input lines if the lines are not connected.

Operation Modes

DT7837 modules support the following digital I/O operation modes:
Synchronous read and write operations – Using software, you can read the value of the digital input port using a synchronous read operation or write a value to the digital output port using a synchronous write operation. The operation is blocking, in that it does not return until the value is read or written.
You do not specify a trigger or clock for a synchronous read or write operation. The operation stops automatically once the value is read or written.
Continuous digital input – Using software, enter the digital input port (all 8 digital input lines) as specify bit 7 of the channel mask in the input stream. You can specify the sampling frequency and trigger source for the input stream. The trigger starts the acquisition. The input sample clock paces the acquisition of data from the digital input port as well as the analog input channels, tachometer input, general-purpose counter/timer, and/or the measure counter.
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Chapter 2
DT7837
#1
DT7837
#2
DT7837
#n
. . .
Device Under
Test
External
Tri gger
Inputs
Inputs
Inputs

Triggering Acquisition on Multiple Modules

The internal clock on the DT7837 module is derived from the 48 MHz crystal oscillator and provides the timing for the analog input subsystem on the module.
You can start acquisition on multiple modules by connecting all modules to a shared external trigger input, as shown in Figure 12. Using software, you must define one of the general-purpose input pins on the Digital connector on each DT7837 module as the external trigger signal. When triggered, the modules start acquiring data at the same time.
Using this connection scheme, the measurements of one module are not synchronous with the measurements of another module as they do not share the same reference clock.
48
Figure 12: Triggering Multiple Modules Using an External Trigger Source
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3

Troubleshooting

Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
If Your Module Needs Factory Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
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Chapter 3

Technical Support

Should you experience problems using the DT7837 module, follow these steps:
1. Read all the appropriate sections of this manual and the DT7837 File I/O Programming
Manual.
2. Refer to the supplied example programs for clarification.
3. Check that you have installed your hardware devices properly.
4. Check that you have installed the software properly.
If you are still having difficulty using the DT7837 module, Data Translation’s Technical Support Department is available to provide technical assistance.
To request technical support, go to our web site at http://www.datatranslation.com and click on the Support link.
When requesting technical support, be prepared to provide the following information:
• Your product serial number
• The hardware/software product you need help on
If you are located outside the USA, contact your local distributor; see our web site (www.datatranslation.com) for the name and telephone number of your nearest distributor.
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If Your Module Needs Factory Service

If your module must be returned to Data Translation, do the following:
1. Record the module’s serial number, and then contact the Customer Service Department at
(508) 481-3700, ext. 1323 (if you are in the USA) and obtain a Return Material Authorization (RMA).
If you are located outside the USA, call your local distributor for authorization and shipping instructions; see our web site (www.datatranslation.com) for the name and telephone number of your nearest distributor. All return shipments to Data Translation must be marked with the correct RMA number to ensure proper processing.
2. Using the original packing materials, if available, package the module as follows:
Wrap the module in an electrically conductive plastic material. Handle with ground
protection. A static discharge can destroy components on the module.
Place in a secure shipping container.
3. Return the module to the following address, making sure the RMA number is visible on
the outside of the box.
Customer Service Dept. Data Translation, Inc. 100 Locke Drive Marlboro, MA 01752-1192
Troubleshooting
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4

Calibration

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Using the Calibration Utility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Calibrating the Analog Input Subsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
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Chapter 4

Overview

DT7837 modules are calibrated at the factory and should not require calibration for initial use. We recommend that you check and, if necessary, readjust the calibration of the analog circuitry every six months using the DT7837 Calibration Utility.
The DT7837 Calibration Utility is provided as both a web application (cal-server) and a command-line program (dt7837cal).
This chapter describes how to calibrate the analog input subsystem of a DT7837 module using the command-line program, dt7837cal.
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Using the Calibration Utility

To use the command-line DT7837 Calibration Utility, perform the following steps:
1. From the usr/local/dt7837/dt7837-calibration directory on the module, type dt7837cal,
and press Enter.
The main screen of the DT7837 Calibration Utility appears.
Calibration
2. Once the calibration utility is running, calibrate the analog input circuitry either
automatically or manually, as described on page 56.
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Chapter 4

Calibrating the Analog Input Subsystem

This section describes how to use the DT7837 Calibration Utility to calibrate each analog input channel of the DT7837 module.

Warming up the Module

Before calibrating the analog input circuitry, ensure that the module has been powered on for at least one hour.

Connecting a Precision Voltage Source

To calibrate the analog input circuitry, you need to connect an external precision voltage source to the DT7837 module that is capable of generating 0.0000 V to +9.3750 V. Connect the precision voltage source to the first analog input channel that you want to calibrate (typically analog input channel 0).

Using the Auto-Calibration Procedure

Auto-calibration is the easiest to use and is the recommended calibration method. To auto-calibrate the analog input subsystem, do the following:
1. From the main menu of the program, select 2: Automatically calibrate an analog input
channel.
2. Enter the number (0 to 3) of the analog input channel that you want to calibrate, then
enter Y to continue.
3. Verify that 0.0000 V is applied to the channel that you want to calibrate.
4. Adjust the value to 0.0000 V by typing a value between 0 and 255 or by pressing the + or
key.
5. Verify that +9.3750 V is applied to the channel that you want to calibrate.
6. Adjust the value to +9.3750 V by typing a value between 0 and 255 or by pressing the + or
key.
7. Verify that +0.9375 V is applied to the channel that you want to calibrate.
8. Adjust the value to +0.9375 V by typing a value between 0 and 255 or by pressing the + or
key.
9. Repeat steps 2 through 8 for the remaining analog input channels on the module.
10. When you have finished calibrating the module, press X from the main menu to exit from
the program.
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Using the Manual Calibration Procedure

The DT7837 has two gains (1 and 10) and two power modes: low power mode and high power mode. Low power mode is calibrated when you specify a sampling frequency less than
52.734 kHz. High power mode is calibrated when you specify a sampling frequency greater than 52.734 kHz. Ensure that you calibrate each analog input channel for gains of 1 and 10 if you are using both gains and for both high and low power mode if you are using sampling frequencies below and above 52.734 kHz. By default, this utility uses DC coupling with the current source disabled.
To manually calibrate the analog input circuitry, do the following for each channel:
1. From the main menu of the program, select 1: Manually calibrate an analog input
channel.
2. Enter the number (0 to 3) of the analog input channel that you want to calibrate.
3. Enter the gain value (1 or 10) to calibrate for the analog input channel.
4. Enter 0 to calibrate the offset potentiometer or 1 to calibrate the gain potentiometer.
5. Enter 0 to calibrate the selected potentiometer for sampling frequencies less than or equal
to 52734 Hz or 1 to calibrate the selected potentiometer for sampling frequencies greater than 52734 Hz.
The current calibrations selections are displayed.
Calibration
6. If the current selections are correct, enter Y. To fix an entry, enter N to repeat these steps.
7. If you chose to calibrate the offset potentiometer in step 4, adjust the potentiometer as
follows:
a. Verify that 0.0000 V is applied to the channel that you want to calibrate.
b. Adjust the value to 0.0000 V by typing a value between 0 and 255 or by pressing the +
or key.
c. Press Enter to display the current information for the channel, including the value of
the potentiometer and the current reading.
d. Repeat steps 7b and 7c until the reading is calibrated to 0.0000 V.
e. Once calibrated, press x to exit to the main menu.
8. If you chose to calibrate the gain potentiometer in step 4 and selected a gain of 1 in step 3,
adjust the potentiometer as follows:
a. Verify that +9.375 V is applied to the channel that you want to calibrate.
b. Adjust the value to +9.375 V by typing a value between 0 and 255 or by pressing the +
or key.
c. Press Enter to display the current information for the channel, including the value of
the potentiometer and the current reading.
d.
Repeat steps 8b and 8c until the reading is calibrated to +9.375 V.
e. Press x to exit to the main menu.
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9. If you chose to calibrate the gain potentiometer in step 4 and selected a gain of 10 in step 3,
adjust the potentiometer as follows:
a. Verify that +0.9375 V is applied to the channel that you want to calibrate.
b. Adjust the value to +0.9375 V by typing a value between 0 and 255 or by pressing the
+ or key.
c. Press Enter to display the current information for the channel, including the value of
the potentiometer and the current reading.
d. Repeat steps 9b and 9c until the reading is calibrated to +0.9375 V.
e. Press x to exit to the main menu.
10. Repeat these steps for each gain and sampling frequency for the selected channel.
11. Repeat these steps for each analog input channel.
12. When you have finished calibrating the module, press X from the main menu to exit from
the program.

Restoring Factory-Calibration Settings

If you wish, you can restore the analog input calibration values for each channel to their original factory settings by selecting 3: Restore all analog input factory calibration settings from the main menu of the DT7837 Calibration Utility.
A prompt is displayed to inform that the values were reset.
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A

Specifications

Analog Input Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Digital Input Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Digital Output Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Tachometer Input Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Measure Counter Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
General-Purpose Counter/Timer Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Trigger Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Master Oscillator Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Power, Physical, and Environmental Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Regulatory Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Connector Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
External Power Supply Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
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Appendix A

Analog Input Specifications

Tabl e 4 lists the specifications for the analog input subsystem on the DT7837 module.
Table 4: Analog Input Subsystem Specifications
Feature DT7837 Specifications
Number of analog input channels 4, single-ended
Resolution 24 bits
Ranges and gains
Gain of 1: Gain of 10:
A/D type Delta Sigma
Data encoding Offset binary
Input FIFO 2 kSamples/s
Maximum sample rate 105.469 kS/s
±10 V ±1 V
Minimum sample rate 195.3125 S/s
ADC master clock range
Sampling frequency
< 52.734 kHz:
52.734 kHz to 105.469 kHz:
Group delay 39/sample rate, in seconds
ADC Delta Sigma filter
Passband, –3 dB: Passband ripple, ±0.005 dB: Stopband, –100 dB:
Analog filter
Low pass cutoff, –3 dB: High pass cutoff, –3 dB (AC coupling):
Channel-to-channel crosstalk
Input Signal = 1 kHz:
Input impedance 1 M
Coupling AC/DC (software-selectable per channel)
IEPE current source 4 mA ±0.5%
IEPE compliance voltage 24 V
a
a
b
100 kHz to 27 MHz
512 x sample frequency 256 x sample frequency
0.49 x sample frequency, Hz
0.453 x sample frequency, Hz
0.547 x sample frequency, Hz
400 kHz
0.1 Hz
–121 dB with 50 Ω termination
Ω || 20 pF
c
60
IEPE current source noise
DC to 1 kHz 5 nARMS
Page 61
DC Accuracy
Offset error
d
Specifications
Table 4: Analog Input Subsystem Specifications (cont.)
Feature DT7837 Specifications
±1 mV
Offset error temperature coefficient ±(7.2
μV/° C )/ Gain) ± 100 μV/° C
Gain error
Gain of 1: Gain of 10:
±0.02% ±0.5%
Gain error temperature coefficient 50 ppm/° C
ADC Integral Non-Linearity error, INL ±0.0006% of full-scale range
ADC Differential Non-Linearity error, DNL Monotonic to 24 bits
Dynamic Performance
Effective Number of Bits, ENOB
e
f
Gain of 1 Gain of 10
(1 kHz input, 105.5 kSPS)
–1 dBFS input: –6 dBFS input:
Signal to Noise and Distortion Ratio, SINAD
15 bits 16 bits
g
(1 kHz input, 105.5 kSPS)
–1 dBFS input: –6 dBFS input:
Signal to Noise Ratio, SNR
h
93 dB 92 dB
(1 kHz input, 105.5 kSPS)
–1 dBFS input: –6 dBFS input:
Total Harmonic Distortion, THD
i
97 dB 96 dB
(1 kHz input, 105.5 kSPS)
–1 dBFS input: –6 dBFS input:
Spurious Free Dynamic Range, SFDR
j
–102 dB –100 dB
(1 kHz input, 105.5 kSPS)
–1 dBFS input: –6 dBFS input:
97 dBFS 103 dBFS
15 bits 16 bits
93 dB 92 dB
97 dB 96 dB
–102 dB –101 dB
98 dBFS 102 dBFS
Noise Floor
Ω input termination, 105.5 kSPS) 56 μVRMS 65 μVRMS
(50
Overvoltage Protection
Overvoltage protection
Power on: Power off:
+40 V to –20 V ±40 V
ESD protection
Arc: Contact:
a. The total frequency response is the combined frequency response of the ADC Delta Sigma filter and the analog filter. b. Channel 0 is the reference channel with a 20 Vpp signal and a maximum sample rate of 105.469 kSamples/s. c. Cable capacitance of 30 pF per foot (typical) must be added. d. Offset errors are referred to the input.
8 kV 4 kV
61
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Appendix A
ENOB
SINAD 1.76 IBFS+()
6.02
-----------------------------------------------------------=
e. ENOB, SINAD, SNR, THD, and SFDR measurements were made with a 16384 point FFT with a minimum 4-term
Blackman Harris window.
f. Effective Number of Bits (ENOB) is calculated from the SINAD value with adjustment for level below full-scale of the
input signal.
where, IBFS is a positive value in dB, representing the ratio of a full-scale signal to the input signal.
g. Signal to Noise and Distortion (SINAD) is the ratio of the RMS value of the input signal to the RMS sum of all other
spectral components, excluding DC.
h. Signal to Noise Ratio (SNR) is the ratio of the RMS value of the input signal to the RMS sum of all other spectral
components, excluding harmonics and DC. i. Total Harmonic Distortion (THD) is the ratio of the RMS value of the input signal to the RMS sum of all harmonics. j. Spurious Free Dynamic Range (SFDR) is the ratio of the RMS full-scale range to the RMS value of the largest peak
spurious component, including harmonics.
62
Page 63

Digital Input Specifications

Tabl e 5 lists the specifications for the digital input signals available on the Digital connector of
the DT7837 module.
Table 5: Digital Input Specifications
Feature Specifications
Number of general-purpose inputs 8
Input type 3.3 V high-speed CMOS, Schmitt trigger, 5 V tolerant
Specifications
Input termination 22.1 k
+ Voltage threshold 2.0 V typical
– Voltage threshold 0.8 V typical
Clocked with sample clock: Yes, if the digital input port is included in the input data stream
Ω pull-up resistor to 3.3 V
(channel/bit 7)
63
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Appendix A

Digital Output Specifications

Tabl e 5 lists the specifications for the digital output signals available on the Digital connector
of the DT7837 module.
Table 6: Digital Output Specifications
Feature Specifications
Number of general-purpose outputs 8
Output type LVTTL
Logic high output voltage 2.4 V minimum
Logic low output voltage 0.4 V maximum
Logic high output current –10 mA maximum
Logic low output current 4 mA maximum
Short circuit current 50 mA maximum
Clocked with sample clock Currently not supported
64
Page 65

Tachometer Input Specifications

Tabl e 7 lists the specifications for the tachometer input available on the Digital connector of
the DT7837 module.
Table 7: Tachometer Input Specifications
Feature Specifications
Number of channels 1
Resolution 31 bits per channel
Input voltage range ±30 V
Threshold voltage +2 V with 0.5 V hysteresis
Input termination None
Maximum input frequency 1 MHz
Specifications
a
Minimum pulse width high/low (minimum amount of time it takes a C/T to recognize an input pulse)
Clock frequency for tachometer measurements 12 MHz (83 ns resolution)
Overvoltage protection ±30 V
Clocked with sample clock: Yes, if the tachometer is included in the input
a. Limited by signal integrity and input signal conditioning.
0.4 μs
data stream (channel/bit 4)
65
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Appendix A

Measure Counter Specifications

Tabl e 8 lists the specifications for the measure counter on the DT7837 module.
Table 8: Measure Counter Specifications
Feature Specifications
Number of measure counters 1
Resolution 31 bits per channel
Clock frequency for measurement counters 48 MHz (20.8 ns resolution)
Maximum input frequency 10 MHz
Minimum pulse width high/low 50 ns (0.4 μs if the tachometer input is used for the
starting edge and stopping edge)
Start and stop signals/edges A/D conversion complete
Tachometer input (falling or rising edge) Digital inputs 0 to 7 (falling or rising edge) C/T 0 Clock input (falling or rising edge) C/T 0 Gate input (falling or rising edge)
a
Clocked with sample clock: Yes, if the measure counter is included in the input data
stream (channel/bit 6)
a. Limited by signal integrity and input signal conditioning.
66
Page 67

General-Purpose Counter/Timer Specifications

Tabl e 7 lists the specifications for the general-purpose counter/timer (C/T 0) on the DT7837
module.
Table 9: General-Purpose Counter/Timer Specifications
Feature Specifications
Number of general-purpose counter/timers 1
Clock sources
Internal: External:
Gate sources
Internal: External:
Counter/timer outputs General-purpose outputs 11 to 18 on the Digital connector
Resolution 32 bits per channel
Clock divider
Minimum: Maximum:
48 MHz reference clock General-purpose inputs 0 to 7 on the Digital connector
Software General-purpose inputs 0 to 7 on the Digital connector
2 4,294,967,296
Specifications
Clock output
Minimum: Maximum:
Maximum clock or gate input frequency 24 MHz
Minimum pulse width (minimum amount of time it takes a C/T to recognize an input pulse)
Input voltage range 0 to 3.3 V (+5 V tolerance)
Inputs
Input logic load: High input voltage: Low input voltage: Low input current: Input termination:
Clocked with sample clock: Yes, if the C/T is included in the input data stream
a. The integrity of the signal degrades at frequencies greater than 10 MHz.
0.0112 Hz 24 MHz
a
50 ns
1 LVTTL
2.0 V minimum
0.8 V maximum –0.8 mA maximum 22 k
Ω
(channel/bit 5)
67
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Appendix A

Trigger Specifications

Tabl e 10 lists the specifications for the triggers on the DT7837 module.
Feature DT7837 Specifications
Trigger sources
Internal software trigger: External digital trigger: Threshold trigger:
External trigger (digital)
Trigger type: Input type: Input termination: + Voltage threshold: – Voltage threshold: Minimum pulse width high/low: Overvoltage protection:
Threshold trigger
Trigger type:
Threshold level: Hysteresis:
Table 10: Trigger Specifications
Software-initiated Software-selectable, general-purpose inputs 0 to 7 on the Digital connector Software-selectable, analog inputs 0 to 3
Edge-sensitive, rising- or falling-edge trigger (software-selectable)
3.3 V high-speed CMOS, Schmitt trigger, 5 V tolerant
Ω pull-up resistor to 3.3 V
22.1 k
2.0 V
0.8 V 250 ns ±30 V
Rising- or falling-edge threshold trigger on any analog input channel (software-selectable)
10 V to +10 V @ gain of 1; ±1 V @ gain of 10
100 mV
Trigger delay 1 conversion period maximum
68
Page 69

Master Oscillator Specifications

Tabl e 11 lists the specifications for the master oscillator on the DT7837 module.
Table 11: Master Oscillator Specifications
Feature Specifications
Frequency 48 MHz
Frequency stability ±30 ppm
a. Stability budget consists of initial tolerance, operating temperature range,
rated power supply voltage change, load change, 10-year aging, shock, and vibration.
Specifications
a
69
Page 70
Appendix A

Power, Physical, and Environmental Specifications

Tabl e 12 lists the power, physical, and environmental specifications for the DT7837 module.
.
Table 12: Power, Physical, and Environmental Specifications
Feature DT7837 Specifications
Power +5 VDC @ 2 A maximum
Warm-up time 1 hour
Physical Dimensions
Depth: Width: Height: Weight:
Environmental Operating temperature range: Storage temperature range: Relative humidity:
Altitude:
6.28 in (159.5 mm)
3.937 in (100 mm)
1.30 in (33 mm)
7.2 oz (204 g)
0° C to 55° C
–25° C to 85° C
To 95%, noncondensing To 10,000 feet
70
Page 71

Regulatory Specifications

The DT7837 module is CE-compliant. Table 13 lists the regulatory specifications for the DT7837 module.
Table 13: Regulatory Specifications
Feature DT7837 Specifications
Emissions (EMI) FCC Part 15, Class A
EN55011:2007 (Based on CISPR-11, 2003/A2, 2006)
Immunity EN61326-1:2006
Electrical Equipment for Measurement, Control, and Laboratory Use
EMC Requirements EN61000-4-2:2009 Electrostatic Discharge (ESD) 4 kV contact discharge, 8 kV air discharge, 4 kV horizontal and vertical coupling planes
EN61000-4-3:2006 Radiated electromagnetic fields, 3 V/m, 80 to 1000 MHz; 3 V/m, 1.4 GHz to 2 GHz; 1 V/m, 2 GHz to 2.7 GHz
Specifications
EN61000-4-4:2004 Electrical Fast Transient/Burst (EFT) 1 kV on data cables
EN61000-4-6:2009 Conducted immunity requirements, 3 Vrms on data cables 150 kHz to 80 MHz
RoHS (EU Directive 2002/95/EG) Compliant (as of July 1st, 2006)
Safety UL, CSA
71
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Appendix A

Connector Specifications

Analog input SMA connectors J1-J5 on I/O block Amphenol Connex 132203
Ethernet (RJ45) connector J1 on ARM block Bothhand LU1S041C-43 LF
USB host connector J2 on ARM block TE Connectivity 292336-1
USB device (client) connector J4 on ARM block TE Connectivity 292304-2
MicroSD connector J5 on ARM block Molex 503182-1853
External power supply
DIN connector:
Tabl e 14 lists the connector specifications for the DT7837 module.
Table 14: Connector Specifications
Board
Connector
Reference
Designator
J6 on ARM block
a
Part Number of Connector
on Module
Kycon KPJX-4S-S
Part Number of
Mating Connector
Kycon KPPX-4P
3-Pin header:
Digital connector J8 on ARM block TE Connectivity 5499786-6
Serial connectors
a. The reference designator indicates the location of the connector on the board. The ARM block is the bottom board and the I/O
block is the top board.
b. The optional EP405 USB to Serial TTL cable attaches to connector J13 and the USB port of your computer.
b
TB1 on ARM block
J12, J13, and J14 on ARM block
Phoenix Contact 1707434
FCI 68000-406HLF
Phoenix Contact 1839610
72
Page 73

External Power Supply Specifications

Tabl e 15 lists the specifications for the option EP361 +5 V external power supply that is used
with the DIN power connector on the DT7837 module.
Table 15: Specifications for the Optional EP361 External Power Supply
Used with the DIN Connector on the DT7837 Module
Feature Specifications
Type Total Power medical power supply (TPEMG24-S050400-7)
Input voltage Typical 90 - 264 V AC
Input current Typical 0.347 A at 115 V AC, 0.215 A at 230 V AC
Frequency 47 to 63 Hz
Inrush current 6.274 A RMS at 230 V AC
Output voltage 5 V DC
Output current 4.0 A
Specifications
Output wattage Typical 20 - 24 W
Noise and ripple 1% peak to peak
Regulatory specifications UL, ITE, CE, FCC Class B, Energy Star compliant
73
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Appendix A
Tabl e 16 lists the specifications for the external power supply that is used with the 3-position
header on the DT7837 module.
Table 16: Specifications for the External Power Supply
Used with the 3-Position Header on the DT7837 Module
Feature Specifications
Output voltage 5 VDC to
Output current 2 A with 4 A surge capability
Noise and ripple 50 mVpp
74
Page 75
B
Connector Pin Assignments and LED
Status Indicators
Analog Input Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Digital Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
USB Device (Client) Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
USB Host Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Ethernet Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Micro SD Card Connector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
External +5 V Power Connector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Serial Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
I/O Block Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
STP26 Screw Terminal Panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
LED Status Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
75
Page 76
Appendix B
Channel n Analog In
Channel n Analog In Return

Analog Input Connectors

Figure 13 shows the layout of the analog input SMA connectors (connectors J1-J5) on the I/O
block (top board) of the DT7837 module.
Figure 13: Analog Input Connectors
76
Page 77

Digital Connector

25 1
26 2
Figure 14 shows the layout of the 26-pin Digital connector (J8) on the ARM block (bottom
board) of the DT7837 module. This connector brings out the tachometer, GPIO, and event output signals for the module.
Figure 14: Layout of the Digital Connector
Tabl e 17 lists the pin assignments for the Digital connector on the DT7837 module.
Connector Pin Assignments and LED Status Indicators
Table 17: Pin Assignments for the Digital Connector
Connector
Pin Number
1 General Purpose Input 0
2 General Purpose Input 1
3 General Purpose Input 2
4 General Purpose Input 3
5 General Purpose Input 4
6 General Purpose Input 5
7 General Purpose Input 6
8 General Purpose Input 7
Signal Description
a
a
a
a
a
a
a
a
9 Digital Ground 22 Digital Ground
10 Digital Ground 23 Tachometer input
11 General Purpose Output 0
12 General Purpose Output 1
13 General Purpose Output 2
b
b
b
Connector
Pin Number
14 General Purpose Output 3
15 General Purpose Output 4
16 General Purpose Output 5
17 General Purpose Output 6
18 General Purpose Output 7
19 Digital Ground
20 Digital Ground
21 Event Out (currently not
supported)
24 Digital Ground
25 +5 V
26 Digital Ground
Signal Description
b
b
b
b
b
a. The input signals are +5 V tolerant and 22 kΩ pull-ups are provided. By default, they are configured as digital
input signals. By default, these signals are configured as digital input signals.
b. The output signals are driven by LVTTL buffers and are capable of providing up to ±24 mA of drive current at
standard LVTTL levels. By default, they are configured as digital output signals. By default, these signals are configured as digital output signals.
77
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Appendix B
Using software, you can specify a general-purpose input signal as the signal source for the following destinations:
• Digital input (the default signal for each general-purpose input pin)
• External A/D trigger input
• Gate input for the general-purpose counter/timer (C/T 0)
• Clock input for the general-purpose counter/timer (C/T 0)
Using software, you can specify a general-purpose output signal as the signal source for one of these destinations:
• Digital output (the default signal for each general-purpose output pin)
• Clock output for the general-purpose counter/timer (C/T 0)
Note that a single general-purpose input may drive several destinations at the same time. However, a single general-purpose output can have only one driving source.
78
Page 79

USB Device (Client) Connector

1
2 3
4
Figure 15 shows the layout of the USB device (client) connector (J4) on the ARM block (bottom
board) of the DT7837 module. This is a type B connector.
Figure 15: Layout of the USB Type B Connector for the USB Device (Client) Port
Connector Pin Assignments and LED Status Indicators
Tabl e 18 lists the pin assignments for the USB type B connector on the DT7837 module for the
USB device (client) port.
Table 18: Pin Assignments for the USB Type B Connector for the USB Device (Client) Port
Connector
Pin Number
1 USB +5 V 3 USB Data +
2 USB Data – 4 USB Ground
Signal Description
Connector
Pin Number
Signal Description
Note: The outer shell provides cable shield to chassis ground.
79
Page 80
Appendix B
1
2
3
4

USB Host Connector

Figure 15 shows the layout of the USB host connector (J2) on the ARM block (bottom board) of
the DT7837 module. This is a type A connector.
Figure 16: Layout of the USB Type A Connector for the USB Host Port
Tabl e 19 lists the pin assignments for the USB type A connector on the DT7837 module for the
USB host port.
Table 19: Pin Assignments for the USB Type B Connector for the USB Device (Client) Port
Connector
Pin Number
1 USB +5 V 3 USB Data +
2 USB Data – 4 USB Ground
Signal Description
Connector
Pin Number
Signal Description
Note: The outer shell provides cable shield to chassis ground.
80
Page 81

Ethernet Connector

12345678
LED1 LED2
Figure 15 shows the layout of the Ethernet (RJ45) connector (J1) on the ARM block (bottom
board) of the DT7837 module.
Figure 17: Layout of the Ethernet Connector
Connector Pin Assignments and LED Status Indicators
Tabl e 20 lists the pin assignments for the Ethernet connector on the DT7837 module.
Table 20: Pin Assignments for the Ethernet Connector
Connector
Pin Number
1 Transmit+ 5 Not connected
2 Transmit– 6 Receive–
3 Receive+ 7 Not connected
4 Not connected 8 Not connected
LED1 Activity (green) LED2 Link (yellow)
Note: The outer shell provides cable shield to chassis ground.
Signal Description
Connector
Pin Number
Signal Description
81
Page 82
Appendix B
Bot t o m Vie w
Card Detect Switch
87654321
9
10
11
12 13
14
15

Micro SD Card Connector

Figure 18 shows the layout of the Micro SD Card connector (J5) on the ARM block (bottom
board) of the DT7837 module.
Tabl e 21 lists the pin assignments for the Micro SD card connector on the DT7837 module.
Table 21: Pin Assignments for the Micro SD Card Connector
Connector
Pin Number
1DAT2 9CD
2 DAT3/CD 10 DGND
3 CMD 11 CGND
4 +3.3 V 12 CGND
5 CLK 13 CGND
6 DGND 14 CGND
7DAT0 15CGND
8DAT1
Figure 18: Micro SD Card Connector
Connector
Signal Description
Pin Number
Signal Description
82
Page 83

External +5 V Power Connector

21
3 4
The DT7837 module provides two connectors for attaching a +5 VDC external power supply: a DIN connector and a 3-position Phoenix header.
Figure 19 shows the layout of the DIN power connector (J6) on the ARM block (bottom board)
of the DT7837.
Figure 19: Layout of the DIN Power Connector
Connector Pin Assignments and LED Status Indicators
Tabl e 22 lists the pin assignments for the external DIN power connector on the DT7837
module.
Table 22: Pin Assignments for the External Power Connector
Connector
Pin Number
1+5 VDC 2+5 VDC
3 Ground 4 Ground
Signal Description
Connector
Pin Number
Signal Description
You can connect the optional EP361 power supply to the DIN connector, if desired. Refer to
page 72 and page 73 for detailed specifications of this power supply.
83
Page 84
Appendix B
Terminal 1
Terminal 2
Terminal 3
Figure 20 shows the layout of the 3-pin Phoenix header (TB1) on the ARM block (bottom
board) of the DT7837 module.
Figure 20: Layout of the 3-Position Phoenix Header
Tabl e 23 lists the terminal assignments for the 3-position header on the DT7837 module.
Table 23: Terminal Assignments for the 3-Position Header (TB1) on the DT7837 Module
Terminal Number Signal Description
1+5 VDC
2 Digital Ground
3 Chassis Ground
Note that you must connect an external power supply to this header that meets the specifications described on page 74.
84
Page 85

Serial Connectors

Serial
Port 1/
I
2
C2 Port
Serial Port 0
SPI
Port
61
*Note that the pin order of connector J13 is reversed from connectors J12 and J14.
Figure 15 shows the layout of the 6-pin serial connectors (J12, J13, and J14) on the ARM block
(bottom board) of the DT7837 module.
Connector Pin Assignments and LED Status Indicators
Figure 21: Layout of the Serial Connectors
These connectors are described in the sections that follow.

Serial Port 0 (UART 0)

Figure 15 shows the layout of the Serial port 0 (J13) on the ARM block (bottom board) of the
DT7837 module.
Figure 22: Layout of Serial Port 0 (J13)
85
Page 86
Appendix B
16
Tabl e 24 lists the pin assignments for serial port 0 on the DT7837 module.
Table 24: Pin Assignments for Serial Port 0 (J13) on the DT7837 Module

SPI Connector

Figure 15 shows the layout of the SPI connector (J12) on the ARM block (bottom board) of the
DT7837 module.
Connector
Pin Number
1DGND
2 Not Connected
3 Not Connected
4UART0_RX
5UART0_TX
6 Not Connected
Signal Description
Figure 23: Layout of SPI Connector (J12)
Tabl e 25 lists the pin assignments for the SPI connector on the DT7837 module.
Table 25: Pin Assignments for SPI Connector (J12) on the DT7837 Module
Pin Number Signal Description
1 SPI1_D0
2 SPI1_SCLK
3 SPI1_CS0
4 SPI1_D1
5DGND
6 +3.3 V
86
Page 87

Serial Port 1 / I2C2 Connector

16
Figure 15 shows the layout of the Serial port 1/ I2C2 connector (J14) on the ARM block
(bottom board) of the DT7837 module.
Figure 24: Layout of Serial Port 1 / I
Connector Pin Assignments and LED Status Indicators
2
C Port (J14)
Tabl e 26 lists the pin assignments for the Serial port 1/ I
Table 26: Pin Assignments for Serial Port 1 / I
Pin Number Signal Description
1UART1_RX
2UART1_TX
3I
4I
5DGND
6 +3.3 V
2
C2_SDA
2
C2_SCL
2
C connector on the DT7837 module.
2
C Connector (J14) on the DT7837 Module
87
Page 88
Appendix B
11 13 15
17 19
1 3
5 7 9
31 33
35 37 39
21
23 25 27
29
51 53 55
57 59
41 43
45 47 49
71 73
75 77 79
61
63 65 67
69
91
93 95 97
99
81 83 85
87 89
111 113 115
117 119
101 103
105 107 109
12 14 16
18 20
2 4
6 8 10
32 34
36 38 40
22
24 26 28
30
52 54 56
58 60
42 44
46 48 50
72 74
76 78 80
62
64 66 68
70
92
94 96 98
100
82 84 86
88 90
112 114 116
118 120
102 104
106 108 110

I/O Block Connector

Figure 15 shows the layout of the I/O block connector (J9) on the DT7837 module.
88
Figure 25: I/O Block Connector (J9)
Page 89
Connector Pin Assignments and LED Status Indicators
Tabl e 27 lists the pin assignments of the I/O block connector on the DT7837 module (on both
the ARM block and the I/O block).
Table 27: Pin Assignments for the I/O Block Connector (J9)
Connector
Pin Number
1+5 V 2+5 V
3+5 V 4+5 V
5 Ground 6 Ground
7 Ground 8 Ground
9 Test 0 10 Test 1
11 Test 2 12 Test 3
13 LED 0 14 LED 1
15 LED 2 16 LED 3
17 LED 4 18 LED 5
19 LED 6 20 LED 7
21 DC/DC Sync 0 22 DC/DC Sync 1
23 Ground 24 Ground
25 I
27 I
Signal Description
2
C SLC 0 26 I2C SLC 1
2
C SDA 0 28 I2C SDA 1
Connector
Pin Number
Signal Description
29 Ground 30 Ground
31 Write Enable 0 32 Write Enable 1
33 Read Enable 0 34 Read Enable 1
35 In Sync Control 0 36 In Sync Control 1
37 In Sync Control 2 38 In Sync Control 3
39 Ground 40 Ground
41 DAQ Clock 0 42 DAQ Clock 1
43 DAQ Clock 2 44 DAQ Clock 3
45 Ground 46 Ground
47 Sync 0 48 Sync 1
49 Data Clock 0 50 Data Clock 1
51 Data Clock 2 52 Data Clock 3
53 Ground 54 Ground
55 In Serial Data 0 56 In Serial Data 1
57 In Serial Data 2 58 In Serial Data 3
89
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Appendix B
Table 27: Pin Assignments for the I/O Block Connector (J9)
Connector
Pin Number
59 In Serial Data 4 50 In Serial Data 5
61 In Serial Data 6 62 In Serial Data 7
63 Ground 64 Ground
65 In Parallel Data 0 66 In Parallel Data 1
67 In Parallel Data 2 68 In Parallel Data 3
69 In Parallel Data 4 70 In Parallel Data 5
71 In Parallel Data 6 72 In Parallel Data 7
73 Ground 74 Ground
75 Control 0 76 Control 1
77 Control 2 78 Control 3
79 Control 4 80 Control 5
81 Control 6 82 Control 7
83 Ground 84 Ground
85 Control 8 86 Control 9
Signal Description
Connector
Pin Number
Signal Description
87 Control 10 88 Control 11
89 Control 12 90 Control 13
91 Control 14 92 Control 15
93 Ground 94 Ground
95 Out Parallel Data 0 96 Out Parallel Data 1
97 Out Parallel Data 2 98 Out Parallel Data 3
99 Out Parallel Data 4 100 Out Parallel Data 5
101 Out Parallel Data 6 102 Out Parallel Data 7
103 Ground 104 Ground
105 Out Serial Data 0 106 Out Serial Data 1
107 Out Serial Data 2 108 Out Serial Data 3
109 Out Serial Data 4 110 Out Serial Data 5
111 Out Serial Data 6 112 Out Serial Data 7
113 Ground 114 Ground
115 Out Sync Control 0 116 Out Sync Control 1
117 Out Sync Control 2 118 Out Sync Control 3
90
119 Ground 120 Ground
Page 91

STP26 Screw Terminal Panel

The STP26 contains one 26-pin connector and a screw terminal block (TB1). The 26-pin connector provides access to the signals from the Digital connector on the DT7837 module.
Figure 26 shows the layout of the STP26 screw terminal panel.
Connector Pin Assignments and LED Status Indicators
Figure 26: Layout of the STP26 Screw Terminal Panel
Tabl e 28 lists the screw terminal assignments for the STP26 screw terminal panel.
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Appendix B
Table 28: Screw Terminal Assignments for the STP26 Screw Terminal Panel
Screw Terminal Signal Description
X Shield
26 Digital Ground
25 +5 V
24 Digital Ground
23 Tachometer Input
22 Digital Ground
21 Reserved for future use
20 Digital Ground
19 Digital Ground
18 General-Purpose Output 7
17 General-Purpose Output 6
16 General-Purpose Output 5
15 General-Purpose Output 4
14 General-Purpose Output 3
13 General-Purpose Output 2
12 General-Purpose Output 1
11 General-Purpose Output 0
10 Digital Ground
9 Digital Ground
8 General-Purpose Input 7
7 General-Purpose Input 6
6 General-Purpose Input 5
5 General-Purpose Input 4
4 General-Purpose Input 3
3 General-Purpose Input 2
2 General-Purpose Input 1
1 General-Purpose Input 0
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LED Status Indicators

Power L ED
Input Trigger LED
Output Trigger LED
The DT7837 module has a Power LED indicator on the ARM block (bottom board) and trigger LEDs on the I/O block (top board), as shown in Figure 27.
Connector Pin Assignments and LED Status Indicators
Figure 27: Power LED on the DT7837 Module
These LEDs are described in Tab l e 29 .
Table 29: LED Status Indicators on the DT7837 Module
LED Color of the LED Status Description
Input Trigger LED
Output Trigger LED
Power LED Off Power off.
Off Idle.
Solid amber Input subsystem armed; it is waiting for an external digital
trigger or threshold trigger (the module must have been configured for one of these trigger types).
Solid green Input subsystem has been triggered.
Off Idle.
Solid amber Output subsystem armed; it is waiting for an external digital
trigger or threshold trigger (the module must have been configured for one of these trigger types).
Solid green Output subsystem has been triggered.
Solid green Power on.
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Appendix B
94
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Index

Index

Symbols

+5 V power connector 83, 84

Numerics

3-position Phoenix header 84
A
accessories
EP405 USB to serial TTL debug cable EP406 cable
STP26 screw terminal panel aliasing AM3352 processor analog input
calibrating
channels
connectors
data format and transfer
error conditions
gain
29
IEPE functions
input range
resolution
sample clock
specifications
triggers ARM block ARM processor
19
19
32
25
56
29
76
33
33
30
29
30
32
60
31
25
25
C
C/T, see counter/timer 66, 67 calibrating the module
analog input subsystem
running the calibration utility channels
analog input
counter/timer
digital I/O
digital input
measure counter
tachometer client port, USB
29
36
47
47
43
34
26
56
55
19
clock sources
analog input counter/timer
connectors
+5 V power analog input digital Ethernet I/O block I2C2
87
micro SD card serial
85
serial port 0 serial port 1 SPI
86
USB client
USB host conversion rate counter/timer
channels
clock sources
gate types
specifications
subsystem specifications counting events coupling type current source customer service
32
37
83
76
77
81
88
82
85 87
79
80
31
36
37
37
67
66
39
30
30
51
D
data encoding 33 data format and transfer, input data DDR3 memory digital connector digital I/O operations
continuous digital input
47
lines
synchronous read
synchronous write digital trigger DIN power connector DT7837 Calibration Utility duty cycle
25
27, 77
47
47
47
31
83
18
38
33
95
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Index
E
EEPROM 25 embedded NAND flash encoding data environmental specifications EP405 USB to serial TTL debug cable EP406 cable errors, analog input Ethernet connector event counting excitation current source external clock external digital trigger
33
19
39
37
25
70
33
81
30
31
F
factory service 51 file I/O commands flash
25
formatting input data FPGA
27
frequency
analog input operations external C/T clock
18
33
32
37
G
gain 29 gate type generating one-shot pulses generating pulses GMPC bus interface group delay
37
41
40
27
32
19
K
kernel device driver 18
L
LED status indicators 93
Input Trigger
Output Trigger
Power lines, digital I/O
93
93
93
47
M
master oscillator 32
specifications measure counter
features
specifications memory micro SD card
25
connector
69
43
66
26
82
N
NAND flash 25 non-repeatable one-shot Nyquist Theorem
41
32
O
oscillator, specifications 69 output pulses Output Trigger LED
40, 41
93
96
H
host port, USB 26
I
I2C2 connector 26, 87 idle mode IEPE features input
channels ranges
resolution Input Trigger LED internal C/T clock internal sample clock
42
30
29
29
30
93 37
32
P
physical specifications 70 polarity of counter output signal ports, digital I/O power connector
3-pin Phoenix header DIN
83
Power LED power specifications processor pulse output
non-repeatable one-shot period pulse width rate generation
pulse width
25
38
47
84
93
70, 74
41
38
40
38
38
Page 97
Index
R
ranges, analog input 29 rate generation regulatory specifications resolution
analog input
digital I/O returning boards to the factory RMA
51
40
71
30
47
51
S
sample clock 32 SD card SDRAM serial connectors serial peripheral interface serial port 0 serial port 1 serial port 1 connector signals used on processor size, module software trigger specifications
SPI connector SPI port start trigger
STP25 screw terminal panel STP26 screw terminal panel
26
25
85
27, 86 26, 85, 86, 87 26
87
27
70
31
59
analog input connector counter/timer counter/timer specifications environmental EP361 external power supply external power for the 3-position header master oscillator physical power regulatory tachometer input triggers
60
72
67
66
70
73
69
70
70
71
65
68
86
27
external digital (TTL) trigger software threshold trigger
31
32
31
91 19, 91
74
technical support threshold trigger transferring input data triggers
external software specifications
threshold troubleshooting TTL trigger type A connector type B USB connector
31
31
50
32
68
32
50
31
80
U
UART 0 85, 86, 87 UART 1 UART0 UART1 units, counter/timer USB client port USB device connector USB device port USB host connector USB host port
87 26 26
36
26
26
80
26
V
voltage ranges 29
W
warm-up time 56
33
79
79
T
tachometer input
features specifications
34
65
97
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Index
98
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