Lord MicroStrain 3DM-CX5 Series User manual

3DM-CX5-GNSS/INS
GNSS-Aided Inertial Navigation System
LORD
USER MANUAL

MicroStrain® Sensing Systems
459 Hurricane Lane
Williston, VT 05495
United States of America
Phone: [phone]
www.microstrain.com
[e-mail]
[email protected]
Copyright © 2019 LORD Corporation
Document 8500-0084 Revision B
Subject to change without notice.

3DM-CX5-GNSS/INS
User Manual
Table of Contents
1. System Overview 1
2. Sensor Overview 2
2.1 Components 3
2.2 Interface and Indicators 4
3. Basic Setup and Operations 5
3.1 Software Installation 6
3.2 System Connections 7
3.3 Software Interface 8
3.3.1 Interactive Help Menu 9
3.4 Sensor Communication 9
3.5 GNSS Satellite Link 11
3.6 Sensor Settings 11
3.6.1 Saving Configurations 12
3.7 Data Monitoringand Recording 13
3.8 View Recorded Data 14
4. Sensor Measurements 16
4.1 Direct Sensor Measurements (IMU Outputs) 17
4.2 Computed Outputs 19
4.3 Sensor Reference Frames 21
4.3.1 Geodetic Frame 21
4.3.2 North East Down (NED) Frame 22
4.3.3 Sensor Frame 23
4.3.4 Platform Frame 24
5. Performance Optimization 26
5.1 Gyroscope Bias 26

3DM-CX5-GNSS/INS
User Manual
5.2 Tare Mounting Pitch-Roll 27
5.3 Magnetometer Auto Calibration 28
5.3.1 Enable 28
5.3.2 Capture 29
5.4 Magnetometer Manual Calibration 30
5.5 Estimation Filter Aiding 33
5.6 Heading Aiding Settings 34
5.6.1 Bias Convergence 35
5.7 Adaptive Anomaly Rejection 35
5.7.1 Gravity Adaptive 35
5.7.2 Mag Adaptive 36
5.8 Angular Rate andAcceleration Limits 37
5.9 Communications Bandwidth 37
5.10 Platform Frame Transformation 37
5.11 Estimation Filter Operation 37
5.12 Estimation Filter Convergence 39
5.12.1 Initial Convergence 39
5.12.2 Output Uncertainty 40
5.13 Vibration Isolation 40
5.14 IMU Sensor Calibration 40
5.15 Temperature Compensation 40
5.16 Import and Export Settings 40
6. Sensor Installation 42
6.1 Sensor Mounting 42
7. OEM System Integration 43
7.1 Data Communications Protocol (DCP) 43
7.1.1 Packet Builder 44

3DM-CX5-GNSS/INS
User Manual
7.1.2 Sensor Direct Mode 44
7.2 Sensor Wiring 46
7.3 Sampling on Start-up 47
7.4 Connecting to a Datalogger 48
7.5 Using Wireless Adapters 48
8. Troubleshooting 49
8.1 Troubleshooting Guide 49
8.2 Repair and Calibration 53
8.3 Maintenance 53
8.4 Technical Support 54
9. Parts and Configurations 55
9.1 Standard Configurations 55
9.2 Accessories 57
9.3 Sales Support 57
10. Specifications 58
11. Reference Diagrams 59
11.1 Sensor Dimensionsand Origin 59
11.2 GNSS Antenna Specifications 60
11.3 Power Supply Specifications (RS232kits only) 61
11.4 Communication andPower Cables 62
12. Reference Documents 64

3DM-CX5-GNSS/INS
User Manual
1
1. System Overview
The LORD Sensing 3DM-CX5 family of industrial-grade 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.

3DM-CX5-GNSS/INS
User Manual
2
2. Sensor Overview
The 3DM-CX5-GNSS/INS is a high-performance, industrial-grade GNSS-Aided Inertial Navigation
System (GNSS/INS) that combines micro inertial sensors and a high- sensitivity embedded Global
Navigation Satellite System (GNSS) receiver for use in a wide range of industrial - grade applications,
such as unmanned vehicle navigation, robotic control, platform stabilization, motion tracking and analysis,
vehicle health monitoring, and device aiming.
The 3DM-CX5-GNSS/INS combines the strengths of an integrated multi-axis gyroscope, accelerometer,
and magnetometer, in combination with GNSS, temperature and pressure readings to provide highly
accurate position, velocity, 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-GNSS/INS to
perform well in a wide variety of applications that require low noise, drift, gain, and offset errors. Uncertainty
monitoring, 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-GNSS/INS communicates through a serial connection and is monitored by a host
computer. A detachable GNSS antenna is plugged into the sensor via a non-magnetic adapter cable and
connector and positioned with unobstructed line of sight to the sky to obtain satellite links. 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-GNSS/INS Sensor

3DM-CX5-GNSS/INS
User Manual
3
2.1 Components
The 3DM-CX5-GNSS/INS Inertial Sensor can be purchased by itself or as part of a Connectivity 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.
Item
Description
Model
LORD Sensing
Part Number
A
3DM-CX5-GNSS/INS Inertial
Sensor
GNSS/INS 8G,
300 DPS*
6271-4260
MIP Monitor Software Suite http://www.microstrain.com/software
* For additional options available see Specifications on page 63
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-GNSS/INS Components

3DM-CX5-GNSS/INS
User Manual
4
2.2 Interface and Indicators
The 3DM-CX5-GNSS/INS sensor interface includes a communications and power input connector and
a GNSS antenna port. The sensor is installed using the mounting and alignment holes as needed.
The indicators on the 3DM-CX5-GNSS/INS include a device status indicator and the device information
label. The table below describes the basic status indicator behavior. The device information label includes
the sensor frame diagram (axis orientation), which will be critical during device installation.
Indicator
Behavior
Device Status
device status
indicator
OFF
no power applied
rapid flash
streaming data with no GNSS
lock
steady blink
streaming data with GNSS
lock
slow pulse
idle mode, awaiting
commands
Figure 2. Sensor Indicator Behaviors

3DM-CX5-GNSS/INS
User Manual
5
3. Basic Setup and Operations
To acquire sensor measurements and computed outputs, the 3DM-CX5-GNSS/INS uses a host
computer, and TTL SERIAL 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 OEM System Integration on page 51 .
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 3. Viewing Sensor Data with MIP Monitor
Do not put the 3DM-CX5-45 in contact with, or in close proximity to,
magnets. Magnets may disrupt operation and cause magnetization of internal components, which can affect
magnetometer performance. If magnetization is suspected, use a degaussing tool to demagnetize.

3DM-CX5-GNSS/INS
User Manual
6
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. Download and open the Iron Calibration .zip file to facilitate magnetometer field
calibration.
7. Run the setup.exe file, and follow the on-screen prompts to completion. If prompted,
reboot the computer when complete.
Figure 4. Software Installation Menu
NOTE
The MIP Monitor Software Suite includes hardware drivers required for 3DM-CX5-45 sensor
operation. Sensors will not be recognized without these drivers installed.

3DM-CX5-GNSS/INS
User Manual
7
3.2 System Connections
To acquire sensor data the following components are needed: 3DM-CX5-GNSS/INS sensor,
communication cable, power cable, GNSS antenna, GNSS non-magnetic antenna adapter cable, and
a host computer with LORD Sensing MIP Monitor installed.
Figure 5. 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 ).

3DM-CX5-GNSS/INS
User Manual
8
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 6. Main Window Display

3DM-CX5-GNSS/INS
User Manual
9
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 7. Context Sensitive Help Menu
3.4 Sensor Communication
Once power has been applied to the sensor, it is functional. The sensor selects the appropriate serial
communication (USB or TTL) 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.
GNSS lock is not required to establish sensor communication.
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.

3DM-CX5-GNSS/INS
User Manual
10
Figure 8. 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.

3DM-CX5-GNSS/INS
User Manual
11
3.5 GNSS Satellite Link
Communication between the GNSS receiver and GNSS satellites is initiated when the 3DM-CX5-
GNSS/INS is first powered on. The receiver will continuously search for satellites until a link is
established. When the link is established, the GNSS Monitor window in the MIP Monitor software will
display the satellite and link statistics.
Communication with the satellites is required for proper sensor operation, although some
measurement outputs will be available without it.
3.6 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-GNSS/INS these include
b. Message Format (first sub-menu tab): Under each main menu tab there are additional sub-
menu tabs, including the Message Format tab, which 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. GNSS
d. Scrolling: used to navigate to additional sub-menus
e. Help button: Enable the context-sensitive help menu for more information.
NOTE
The GNSS antenna requires unobstructed line of sight with the sky in order to achieve
communication with the GNSS satellites.

3DM-CX5-GNSS/INS
User Manual
12
Figure 9. Device Settings Menu
3.6.1 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 10 - 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 10. Save Sensor Settings

3DM-CX5-GNSS/INS
User Manual
13
3.7 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.
Icon
Command
Run:
start data streaming
Stop:
end data streaming
Step:
sample single set of data
Record:
start and stop data recording
Figure 11. 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-GNSS/INS includes Sensor Data Monitoring for the
IMU/AHRS measurements, GNSS Monitoring for the GNSS metrics, and EF Monitoring for the
Estimation Filter outputs. During viewing and recording only the outputs that are selected in the
Message Format tab of the Device Settings menu are displayed and recorded (
see Sensor Settings on
page 17
).
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.

3DM-CX5-GNSS/INS
User Manual
14
Figure 12 - 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. Click the blue Start Streaming icon to start sampling.
3.8 View Recorded Data
Figure 12. Data Streaming
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.

3DM-CX5-GNSS/INS
User Manual
15
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 13. Data Recording
4. To end recording press the Arm Recording button 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.
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.