JEWELL DX Series User manual

DX Series
User’s Manual
For DXA-200/100 Accelerometers and DXI-200/100 Inclinometers
Jewell Instruments, LLC
850 Perimeter Road
Manchester, NH 03103
Telephone: [phone] Email: [e-mail]

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Contents
1. General Information...................................................................................................................6
A. About this Manual ..................................................................................................................6
i. Related Documentation / Applications.........................................................................6
ii. Documentation Conventions...........................................................................................6
B. Warranty ...................................................................................................................................7
2. Product Overview.......................................................................................................................8
A. Introduction to the DX Series ................................................................................................8
i. Features and Options.........................................................................................................8
ii. Internal Diagram .................................................................................................................9
iii. Typical Applications .........................................................................................................10
B. DX Series Installation.............................................................................................................10
i. Mechanical........................................................................................................................10
ii. Electrical .............................................................................................................................12
3. Basic Operating Tenants.........................................................................................................13
A. Getting Started......................................................................................................................13
i. Default Settings..................................................................................................................13
ii. Terminal Programs.............................................................................................................14
iii. Connecting to the Serial Interface ...............................................................................14
B. Operational Modes..............................................................................................................14
i. RS422....................................................................................................................................15
ii. RS485....................................................................................................................................15
iii. Temporary RS485...............................................................................................................15
C. Serial Communications........................................................................................................16
i. Packet Structure................................................................................................................16
ii. Using DX Series Commands ............................................................................................19
4. Building Command Structures...................................................................................................20
A. Full List of Serial Commands................................................................................................21
i. Configuring Measurement Outputs ..............................................................................21
ii. Configuring Transmission Parameters ...........................................................................25
iii. Maintenance and Infrastructure Inputs .......................................................................29

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5. Responses from the DX Series Sensor....................................................................................36
A. ACK and NAK ...........................................................................................................................36
B. 7 Byte Measurement Output .................................................................................................37
i. DXI Decoding.....................................................................................................................38
ii. DXA Decoding...................................................................................................................40
6. Additional Information.............................................................................................................44
A. Errors and Flash Memory Verification ...............................................................................44
B. Troubleshooting.....................................................................................................................45
C. Guidelines and Effective Output Rate Selection ...........................................................46
D. Mounting Considerations....................................................................................................46
E. Line Resistance Effects.........................................................................................................47
Appendix A: Condensed Command Set ...................................................................................48
1. Measurement Outputs.........................................................................................................48
2. Transmission Parameters......................................................................................................50
3. Maintenance & Infrastructure............................................................................................52
Appendix B: Technical Documentation......................................................................................55

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1. General Information
This section will provide general notes and conventions about the product, its
manual, and any other resources which may be available for assistance.
A. About this Manual
This manual will cover the installation and operation of a Jewell Instruments DX
Series force balance digital sensor. Topics will include Operations, Specifications,
Product Information, Best Practices, and more, all related to the DX Series sensor. In
order to best understand the DX Series Sensor it is recommended to place the Unit
under evaluation conditions and preform commands simultaneously with the user’s
guide.
i. Related Documentation / Applications
In addition to this manual there are additional resources that are available for
interfacing with your DX Series Unit. The two additional resources in addition to the user
guide would be:
•DX Series Quick Start Guide
•DX Series Interface Platform Application
The DX Series Quick Start Guide is an abbreviated version of this manual for fast set up
time providing only the minimum of information in order to begin operation with the DX
Series Unit. It should not be used as a substitute for this document however could prove
useful for those new to the unit or where a reminder set of information is helpful.
The DX Series Interface Platform is a pre-packaged Labview application/vi which
automates most of the functionality of a DX series into a GUI for simple operation. The
Interface Platform is available for distribution via the Sales Department of Jewell
Instruments or your local distributor at no cost. Please contact the distributor or Jewell
Instruments Sales at 603.669.6400.
ii. Documentation Conventions
Throughout this manual certain language or mathematical conventions will be used in
order to accurately represent and evaluate outputs. These conventions may break
traditional grammar and spelling behaviors, including abbreviations, bitwise and
hexadecimal representation with prefixes, etc…
•Hexadecimal notation for inputs and outputs is shown throughout this manual will
be shown by a leading ‘$’ or ‘0x’ prefix followed by the MSB. Binary inputs will be
designated as ‘0b’ followed by the binary output MSB first.
Example: 0xA6 = $A6 = [0b1010 0110]

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•C programming language conventions are used in this manual to give practical
decoding examples.
•RS485 Transmission protocol and the corresponding RS485 operational mode are
referred to as 485. The same convention is used for RS422 and the corresponding
RS422 Operational Mode as 422.
•The use of words and phrases which have an underline refer to executable
commands for which further information is provided. They will most be used in the
Operations section of this manual as well as Appendix A: Condensed Command
List.
Example: “In order to switch from 485 to 422 preform a RESET after saving to flash
with the DX series unit in the correct operational mode
•When referring to the DX Series Model for communication, installation, or other
functions the following alternative words and phrases may be used: UUT (Unit
Under Test) , DUT (Device Under Test), DX Series Unit/Sensor.
•When referring to the Labview VI, Computer Application, PC, or other receiving
body which is the primary destination for data from the DX Series device the
following words and phrases may be used: Host, Terminal, Function, Application,
Program.
B. Warranty
Seller warrants its products to be free from defects workmanship and material.
Seller’s liability is limited to replacing the instrument, or any part thereof, that is returned
by the original purchaser, transportation paid, to the factory within on (1) year after
date of shipment, provided that the Seller’s examination shall disclose that a defect
existed under proper and normal use. Seller shall not be responsible for consequential
damages of any kind. This warranty is in lieu of all other warranties, liabilities or
obligations to the Buyer or any other person.

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2. Product Overview
The DX series is a Force Balance based approach to acceleration and inclination
detection. It builds upon the established force balance servo based sensing system
Jewell Instruments is known for and adds a digital backend for enhanced functionality.
It utilizes a dedicated microcontroller for individual axis control, as well as error
detection and multiple unit installation on a single bus.
A. Introduction to the DX Series
The DX Series by Jewell Instruments is comprised of Digital Accelerometers and
Inclinometers. The sensors can have either single or dual sensitive axes on a single
digital output bus. Each unit’s analog front end works with the digital interface to
produce data in one of two transmission modes which communicate via a 2-wire
differential line. When using RS485 protocol (default) operating in half duplex each unit
is capable of 2 way communication. In the inverse configuration the unit is operating in
an emulated RS422 mode, more about this in the Operating modes. Transmissions to
and from the device are in a custom binary format which require encoding and
decoding for each operation or output. The output type of the unit is in either
thousandths of a degree (DXI) or a fractional acceleration (DXA) format as outlined in
each sub-section of this document DXA/DXI Decoding.
In addition to those digital characteristics each unit can take a wide single
supply range of 10V to 30V. The unit connects to external sources by a 13 pin locking
barrel plug; more information can be found in the Mechanical section. By default DX
Series units are shipped in the following configuration: RS485, 38.4k Baud Rate, with No
Averaging, Normal Polarity.
i. Features and Options
The DX series sensor enhances the capabilities of the standard servo output of
our other product offerings. Each DX series unit has the capability of adjusting several
out its output, transmission and data manipulation characteristics to best suit each
individual application. In addition to the standard series of features each DX series
model has a CENELAC / AREMA Model. The type “–R” models CENELAC and AREMA
model is qualified for the following abbreviated standards:
CENELEC EN 55022:2010

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CENELEC EN 50155:2007
CENELEC EN 61000-4-8:2010
AREMA Part 11.5.1
For the complete test plan and results please contact Jewell Instruments Sales
Department.
ii. Internal Diagram
The core of the DX Series is based on the same force balance sensors which drive
Jewell’s analog sensor offerings. This front back end consists of a torquer, servo, position
detector, and various signal conditioning circuits. The analog back end then is fed into
the microcontroller and control system as shown in the following Figure 1: DX Series Top
Level Hardware Block Diagram.
Figure 1: DX Series Top Level Hardware Block Diagram
Note: The analog / digital relationship is one way as the DSP does not actively modify
the analog back end. It does however play a role in the conditioning and A/D sub-
circuit.

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iii. Typical Applications
The Jewell instruments DX series is suited for a wide range of applications and
functions. Its differential line transmission allows for greater distance from unit to host
and vice versa. For DXA/DXI applications we recommend it for the control and
monitoring of the following types of systems:
Radar/Antenna
Structural
Linear Acceleration and Deceleration
Automatic Train Position
Seismic
Platform Leveling
Of course the applications for the DX series are not limited to these fields, but have
potential anywhere a linear acceleration or incline needs to be accounted for.
B. DX Series Installation
This section will cover the electrical and mechanical installation of the DX Series
digital senor. It will provide diagrams and other illustrations to assist in the initial physical
setup of the sensor. All functional elements of the unit including communication,
operating modes, and decoding will be covered in the Operations section of this User
Guide.
i. Mechanical
The DX series was designed for maximum compatibility with the Jewell
Instruments LCF-2330 Sensor therefore it uses the same form factor and dimensions. It is
a sealed unit with a military style locking barrel plug and an IP rating of 67. In addition
to its static response, the sensor is designed to resist corrosion and is unit is rated to IP67
and 1500g, 1msec, ½ sine shock tolerance.
1. Matting Connectors
The standard connector on any DX series model is a 13 pin locking barrel plug
with male pins, model type: MS27476Y10D35P.