LORD 3DM-CX5-25 User manual

3DM®-CX5-25
Attitude and Heading Reference System (AHRS)
LORD User Manual

MicroStrain® Sensing Systems
459 Hurricane Lane
Suite 102
Williston, VT 05495
United States of America
Phone: [phone]
www.microstrain.com
[e-mail]
[e-mail]
Copyright © 2018 LORD Corporation
3DM®, 3DM-DH®, 3DM-DH3®, 3DM-GX2®, Ask Us How™, DEMOD-DC®, DVRT®, EmbedSense®, FAS-A®, G-Link®,
Little Sensors, Big Ideas.®, LORD Microstrain®, Live Connect™, LXRS®, MathEngine®, MicroStrain®, MIP™, MXRS®, Node
Commander®, SensorCloud™, SensorConnect™, SG-Link®, Strain Wizard®, TC-Link®, V-Link®, Wireless Simplicity,
Hardwired Reliability™, and WSDA® are trademarks of LORD Corporation.
Document 8500-0082 Revision B
Subject to change without notice.

3DM®-CX5-25 User Manual
Table of Contents
1. System Family Overview 6
2. Sensor Overview 7
2.1 Components 8
3. Basic Setup and Operations 9
3.1 Software Installation 10
3.2 System Connections 11
3.3 Software Interface 12
3.3.1 Interactive Help Menu 12
3.4 Sensor Communication 13
3.5 Sensor Settings 14
3.5.1 Saving Configurations 15
3.6 Data Monitoringand Recording 16
3.7 View Recorded Data 18
3.8 Interface and Indicators 20
4. Sensor Measurements 21
4.1 Direct Sensor Measurements (IMU Outputs) 22
4.2 Computed Outputs(Estimation Filter) 24
4.3 Sensor Reference Frames 26
4.3.1 Geodetic Frame 26
4.3.2 North East Down (NED) Frame 27
4.3.3 Sensor Frame 28
4.3.4 Platform Frame 29
5. Performance Optimization 31
5.1 Gyroscope Bias 31
5.2 Tare Mounting Pitch-Roll 32

3DM®-CX5-25 User Manual
5.3 Magnetometer Auto Calibration 33
5.3.1 Enable 33
5.3.2 Capture 34
5.4 Magnetometer Manual Calibration 35
5.5 Estimation Filter Aiding 38
5.6 Heading Aiding Settings 39
5.6.1 Bias Convergence 40
5.7 Adaptive Anomaly Rejection 40
5.7.1 Gravity Adaptive 40
5.7.2 Mag Adaptive 41
5.8 Communications Bandwidth 42
5.9 Platform Frame Transformation 42
5.10 Estimation Filter Operation 42
5.11 Estimation Filter Convergence 43
5.11.1 Initial Convergence 43
5.11.2 Output Uncertainty 43
5.12 Vibration Isolation 44
5.13 IMU Sensor Calibration 44
5.14 Temperature Compensation 44
6.1 Import andExport Settings 45
7. Sensor Installation 46
7.1 Sensor Mounting 46
8. System Integration 47
8.1 Data Communications Protocol (DCP) 47
8.1.1 Packet Builder 48
8.1.2 Sensor Direct Mode 49
8.2 Sensor Wiring 50

3DM®-CX5-25 User Manual
8.3 Sampling on Start-up 51
8.4 Connecting to a Datalogger 52
8.5 Using Wireless Adapters 52
9. Troubleshooting 53
9.1 Troubleshooting Guide 53
9.2 Repair and Calibration 56
9.3 Maintenance 57
9.4 Technical Support 57
10. Parts and Configurations 58
10.1 Standard Configurations 58
10.2 Accessories 60
10.3 Sales Support 60
11. Specifications 61
12.1 3DM-CX5 Development Kit 63
13. Reference Documents 64
14. Glossary 65

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1. System Family Overview
The LORD Sensing 3DM-CX5 family of high-performance, industrial-grade, board-level inertial sensors
provides a wide range of triaxial inertial measurements and computed attitude and navigation solutions.
In all models, the Inertial Measurement Unit (IMU) includes direct measurement of acceleration and
angular rate, and some also offer atmospheric pressure readings. In models that include a Kalman Filter,
sensor measurements are processed through an Extended Kalman Filter (EKF) to produce highly
accurate computed outputs. The 3DM-CX5 features include extremely stable and low-noise gyros a new
accelerometer with noise densities as low as 25 µg/√Hz, and a multi-constellation GNSS receiver. The M7
and M4 dual Cortex processors run a new Auto-Adaptive EKF. The Kalman filter enables compensation
for magnetic and linear acceleration anomalies as applicable to the model. It also provides sensor bias
tracking, auto-zero update options (ZUPT), and user adjustable sensor noise factors. All sensors are fully
temperature-compensated and calibrated over the full operating temperature range.
The use of Micro-Electro-Mechanical System (MEMS) technology allows for small, lightweight devices.
Sensors are integrated into customer systems using serial communication protocols such as RS422,
RS232 and USB. The LORD Sensing MIP Monitor software can be used for device configuration, real
time measurement monitoring, and data recording. The LORD Sensing MIP Data Communications
Protocol (DCP) that is used to communicate with LORD Sensing inertial sensors is also available for users
who want to develop customized software solutions. Because of the unified set of commands across the
sensor family, it is easy to migrate code from one inertial sensor to another.
Common applications of LORD Sensing inertial sensor products include vehicle health monitoring,
platform stabilization, down-hole and drilling operations, and inertial navigation systems such as
unmanned air and ground vehicles and personal navigation systems.

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2. Sensor Overview
The 3DM-CX5-25 is a high-performance, industrial-grade, board-level Attitude and Heading Reference
System (AHRS) that utilizes micro inertial sensors for use in a wide range of industrial-grade applications,
such as unmanned vehicle navigation, platform stabilization, and vehicle health monitoring.
The 3DM-CX5-25 combines the strengths of an integrated multi-axis gyroscope, accelerometer, and
magnetometer, in combination with temperature and pressure readings to provide highly accurate
attitude (including heading), and inertial measurements. All sensor measurements are temperature-
compensated and are mathematically aligned to an orthogonal coordinate system. The combination of
sensors, environmental compensation, and dual on- board processing with an Auto-Adaptive Extended
Kalman Filter (EKF) allows the 3DM-CX5-25 to perform well in a wide variety of applications that
require low noise, drift, gain, and offset errors. scale factor estimation, and bias estimation outputs are
available. Settings for sensor filtering, sensor noise, and sensor bias, offer many adjustments for specific
application needs.
The 3DM-CX5-25 communicates through a serial connection and is monitored by a host computer.
Sensor measurements and computed outputs can be viewed and recorded with the LORD Sensing
MIP Monitor software that is available as a free download from the LORD Sensing website. Alternatively,
users can write custom software with the LORD Sensing open source data communication protocol. The
data is time-aligned and available by either polling or continuous stream.
Figure 1 - 3DM-CX5-25 Sensor

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2.1 Components
The 3DM-CX5-25 Inertial Sensor can be purchased by itself or as part of a Development Kit. All
software, drivers, and links to detailed documentation are included with the sensor purchase. For a
complete list of available configurations, accessories, additional system products, and ordering
information, see Parts and Configurations on page 58 .
Item
Description
Model
LORD Sensing
Part Number
A
3DM-CX5-25 Inertial Sensor
AHRS 8G, 300
DPS*
6273-4220
MIP Monitor Software Suite http://www.microstrain.com/software
* For additional options available see Specifications on page 61
USB Development Kit
B
USB Communication Cable
--
6212-3009
C-Series Connectivity Board
Ribbon Cable
RS232 Development Kit
C
RS232 Communication Cable
--
6212-3010
RS232 Power Supply and Plug
Adapters
C-Series Connectivity Board
Ribbon Cable
Table 1 - 3DM-CX5-25 Components

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3. Basic Setup and Operations
To acquire sensor measurements and computed outputs, the 3DM-CX5-25 uses a host computer, an
RS232 or USB communications port, and applicable software. The LORD Sensing MIP Monitor software
is provided with the system and includes all functions needed for sensor configuration and data
acquisition. Users may also utilize the LORD Sensing MIP Data Communications Protocol (DCP) to write
custom software applications with expanded or specific feature sets needed for the application.
MIP Monitor includes a message building tool that can be used to streamline this process. For more
information, see System Integration on page 47 .
In this section, hardware and software setup is described, including an overview of the MIP Monitor
software menus required to configure a sensor and begin data acquisition. This is not a complete
demonstration of all system or software features and capabilities.
Figure 2 -Viewing Sensor Data with MIP Monitor

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3.1 Software Installation
To Install the MIP Monitor software on the host computer, complete the following steps:
1. Launch the MIP Monitor software installation menu at:
https://www.microstrain.com/software.
2. Download and open the MIP Monitor .zip file.
3. Run the setup.exe file, and follow the on-screen prompts to completion.
4. Download and open the Inertial Drivers zip folder to install the hardware drivers required
for operating thesensor.
5. Run the .msi file, and follow the on-screen prompts to completion.
6. Run the setup.exe file, and follow the on-screen prompts to completion. If prompted,
reboot the computer when complete.
Figure 3 -Software Installation Menu
NOTE
The MIP Monitor Software Suite includes hardware drivers required for 3DM-CX5-25 sensor
operation. Sensors will not be recognized without these drivers installed.

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3.2 System Connections
To acquire sensor data the following components are needed: 3DM-CX5-25 sensor, communication
cable, power cable (as applicable for RS232 communications), connectivity board, and a host
computer with LORD Sensing MIP Monitor installed.
Figure 4 -System Connections
Power is applied to the sensor through an external power
supply, such as the one provided in the kit. Use only power
supplies within the operating range of the sensor, or damage
or injury could result. Once power is applied the sensor is on
and active ( see Specifications on page 61 ).

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3.3 Software Interface
The MIP Monitor software includes a main window with system information and menus, a device
settings window, and several data monitoring windows.
The main window provides an overview of connected devices. Devices are selected by clicking on
them. A device menu is available by right-clicking on the device name and includes the most used items
from the header row menus. The header row menu includes selections for data sampling, recording,
device settings, opening windows, selecting which open window to view, and advanced features such
as selecting the communications mode. The icon toolbar includes buttons for Help Menu access,
where all related documentation is available in Web Resources, device refresh, and data sampling and
recording.
Figure 5 - Main Window Display
3.3.1 Interactive Help Menu
MIP Monitor also includes a mouse-over feature that provides explanations of the information and
settings. This feature is enabled by selecting the question mark icon or Help button in any window.
Figure 6 - Context Sensitive Help Menu

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3.4 Sensor Communication
Once power has been applied to the sensor, it is functional. The sensor selects the appropriate serial
communication (USB or RS232) on power-up based on which cable is connected. If the hardware
drivers have been installed, communication can be established using the MIP Monitor software
interface.
1. Verify the sensor device status indicator is on.
2. Open the MIP Monitorsoftware.
3. The sensor should appear in the device list automatically when the software is running.
The list includes the device information and communication port assignment. If the
sensor is not automatically discovered, use the refresh button.
Figure 7 -Sensor Communication
NOTE
If data is not actively being exchanged between the sensor and host computer, the status
message may display Not Connected. This indicates the port status, not the sensor
availability. When commands are sent to the sensor, the software will automatically connect
to it before sending the message.

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3.5 Sensor Settings
Device settings are stored in the sensor memory. Only the configuration options available for the
sensor being used are displayed in the menus.
To enter the settings menu, either right-click on the sensor name highlighted in the main window, and
then select Device Settings, or select Settings > Device from the main menu.
a. Main menu tabs: The main tabs divide the settings into functional groups for the available
measurements. For the 3DM-CX5-25 these include calculated measurements (Estimation
Filter) and direct inertial sensor measurements(IMU/AHRS).
b. Message Format (first sub-menu tab): allows the user to select the measurement type to be
displayed and recorded (b1) and the data rate in samples/second (b2).
c. Measurement parameters: Available sub-menu tabs depend on the selected main menu tab.
They include the configurable settings for each measurement.
d. Scrolling: used to navigate to additional sub-menus
e. Help button: Enable the context-sensitive help menu for more information ( see Interactive
Help Menu on page 12 ).
Figure 8 -Device Settings Menu

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3.5.1 Saving Configurations
Sensor settings are saved temporarily by selecting the OK button in the Device Setup window after
configuration, but they are lost when the device is powered off. To save current settings, so they are
automatically restored the next time the device is powered on, select Settings > Save Current
Settings.
First adjust the sensor settings to the desired values. Next select Settings > Save Current Settings
from the main window ( Figure 9 - Save Sensor Settings ). The settings will now remain intact when
the sensor is powered off and then on again.
To recall the last saved settings select Settings > Load Startup Settings. To revert the settings back
to the factory defaults, select Settings > Load Default Settings.
Figure 9 -Save Sensor Settings

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3.6 Data Monitoring and Recording
Throughout the MIP Monitor views the same icons are used to control data streaming (sampling) and
recording. These icons can be found in the MIP Monitor main window icon toolbar and in each data
monitoring window. The same commands are also found in the main window Control menu.
Figure 10 -Main Window Controls
There are several data monitoring views available depending on what measurements are desired for
monitoring and recording. Each view corresponds to one of the main categories in the Device Settings
window. For example, the 3DM-CX5-25 includes Sensor Data Monitoring for the IMU/AHRS
measurements and EF Monitoring for the Estimation Filter output. During viewing and recording, only
the outputs that are selected in the Message Format tab are displayed and recorded ( see Sensor
Settings on page 14 ).
Data streaming must be started in order for data to be recorded, however it is not necessary to view it in
a data monitoring window. Data monitoring is used primarily to confirm the system is operating
correctly or to view the outputs in near real time. If sensor setup has already been confirmed, streaming
and recording can be initiated from the main window.

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Figure 11 - Data Streaming is an example of Sensor Data Monitoring, which displays the selected
IMU/AHRS measurements. In data monitoring windows, no data will be displayed until data streaming
is started, and no data will be recorded (even if it is being viewed) until data recording is initiated
(armed). In the example below, the y-axis of the graph indicates data points, the x-axis is the
measurement units, and there is a tab for each measurement.
1. Right- click on the device in the MIP Monitor software main window, and select
Sensor Data Monitor.
2. Select the blue Start Streaming icon to start sampling.
Figure 11 -Data Streaming

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3.7 View Recorded Data
Recorded data is stored in either Binary (.bin) or Comma Separated Values (.csv) format,
depending on what was selected at the initiation of data recording. The files can be found in the
directory specified at that time or in the default directory on the host computer desktop.
CSV files can be viewed with Microsoft Excel, Quattro Pro, Open Office, or other CSV editors
and spreadsheet programs.
Data recorded in Binary format requires a translation program utilizing the LORD Sensing
MIP Data Communications Protocol (DCP) to make it user-readable.
1. To record data, select the Arm Recording icon at any time.
2. Select the type of data file to generate: Binary or CSV. The CSV file is the most common
and can be viewed and processed by data editors such as Microsoft Excel.
3. To save a settings file when creating a data file, check the box next to this option. This
settings file is the same as selecting Export Settings from the Settings menu.
Figure 12 -Data Recording
NOTE
If the data is recorded in Binary format it will require a translation program that
utilizes the LORD Sensing MIP Data Communications Protocol (DCP) to make it
user-readable.

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4. To end recording press the Arm Recording button again, and select OK in the confirmation
prompt window.
5. Select the Stop Streaming icon to end sampling.
6. Use the red "X" in the upper right of the sensor monitoring window to exit monitoring mode.

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3.8 Interface and Indicators
The 3DM-CX5-25 sensor interface includes a communications and power input connector. The sensor
is installed using the mounting and alignment holes as needed ( see Sensor Mounting on page 46 ).
The indicators on the 3DM-CX5-25 include a device status indicator and the device information label.
The table below describes the basic status indicator behavior. includes the sensor frame diagram (axis
orientation), which will be critical during device installation ( see Sensor Frame on page 28 ).
Indicator
Behavior
Device Status
device status
indicator
OFF
no power applied
rapid flash
streaming data
slow pulse
idle mode, awaiting
commands
Figure 13 -Senor Indicator Behaviors