Data Translation DT7837 User manual

DT7837
UM-26000-A
User’s Manual
Title Page

First Edition
March, 2015
Data Translation, Inc.
100 Locke Drive
Marlboro, MA 01752-1192
[phone]
www.datatranslation.com
Fax: [phone]
E-mail: [email protected]
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.
Copyright Page

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.
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.
FCC
Page

5
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
Table of Contents

Contents
6
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

Contents
7
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 / I2C2 Connector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
I/O Block Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
STP26 Screw Terminal Panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
LED Status Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

Contents
8

9
About this Manual
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.
•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.

About this Manual
10
Related Information
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.
Where To Get Help
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).

11
1
Overview
Hardware Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Supported Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Supported Accessories. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Getting Started Procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Chapter 1
12
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.
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.

Overview
13
• 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.
−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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• Serial debug port.
• External power connectors (4-pin DIN or 3-pin Phoenix header) for connecting a +5 VDC
power supply.

Overview
15
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).

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Figure 2: Layout of the ARM Block of the DT7837 Module
Digital Connector
(Tachometer, Digital I/O, External Trigger, Counter/Timer)
Power LED
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

Overview
17
Figure 3: Layout of the I/O Block of the DT7837 Module
Output Trigger
LED (bottom)
Input Trigger LED
(top)
Analog Output Connector
(analog output currently not
supported in software)
Analog Input Connectors

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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.

Overview
19
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.
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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•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