LORD MicroStain 3DM-GX5-45 User manual

LORD DATA COMMUNICATIONS PROTOCOL MANUAL
3DM-GX5-45
GNSS-Aided Inertial Navigation System (GNSS/INS)

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 © 2016 LORD Corporation
3DM®, 3DM-DH®, 3DM-DH3™, 3DM-GX1®, 3DM-GX2®, 3DM-GX3®, 3DM-GX4-15™, 3DM-GX4-25™, 3DM-GX4-45™,
3DM-GX4™, 3DM-GX5™3DM-RQ1™,3DM-GQ4™, AIFP®, Ask Us How™, Bolt-Link®, DEMOD-DC®, DVRT®, DVRT-Link™,
EH-Link®, EmbedSense®, ENV-Link™, FAS-A®, G-Link®, G-Link2™, HS-Link®, IEPE-Link™, Inertia-Link®, Little Sensors, Big
Ideas.®, Live Connect™, LXRS®, MathEngine®, MicroStrain®, MVEH™, MXRS®, Node Commander®, PVEH™, RHT-Link®,
RTD-Link™, SensorCloud™, SG-Link®, Shock-Link™, Strain Wizard®, TC-Link®, Torque-Link™, V-Link®, Watt-Link™, Wireless
Simplicity, Hardwired Reliability™, and WSDA®are trademarks of LORD Corporation.
Document 8500-0064 Revision C
Subject to change without notice.

3DM-GX5-45™GNSS-Aided Inertial Navigation System DCP Manual
Table of Contents
1. API Introduction 10
2. Basic Programming 11
2.1 MIP Packet Overview
11
2.2 Command Overview
13
2.2.1 Example “Ping” Command Packet 13
2.2.2 Example “Ping” Reply Packet 14
2.3 Data Overview
15
2.3.1 Example Data Packet: 15
2.4 Example Setup Sequence
16
2.4.1 Continuous Data Example Command Sequence 16
2.4.1.1 - Step 1: Put the Device in Idle Mode
16
2.4.1.2 - Step 2: Configure the IMU Data-stream Format
17
2.4.1.3 - Step 3: Configure the Estimation Filter Data-stream Format
18
2.4.1.4 - Step 4: Save the IMU and Estimation Filter MIP Message Format
19
2.4.1.5 - Step 5: Enable the IMU and Estimation Filter Data-streams
20
2.4.1.6 - Step 6:(Optional): Resume the Device
21
2.4.1.7 - Step 7: Initialize the Filter
22
2.4.2 Polling Data Example Sequence 23
2.4.2.1 - Step 1: Put the Device in Idle Mode (Disabling the IMU and Estimation Filter data-
streams)
23
2.4.2.2 - Step 2: Configure the IMU data-stream format
23
2.4.2.3 - Step 3: Configure the Estimation Filter data-stream format
23
2.4.2.4 - Step 4: Save the IMU and Estimation Filter MIP Message format
23
2.4.2.5 - Step 5: Resume the Device
23
2.4.2.6 - Step 6: Initialize the Filter
23
2.4.2.7 - Send Individual Data Polling Commands
23

3DM-GX5-45™GNSS-Aided Inertial Navigation System DCP Manual
2.5 Parsing Incoming Packets
25
2.6 Multiple Rate Data
26
2.7 Data Synchronicity
27
2.8 Communications Bandwidth Management
27
2.8.1 UART Bandwidth Calculation 28
2.8.2 USB vs. UART 29
3. Command and Data Summary 30
3.1 Commands
30
3.1.1 Base Command Set (0x01) 30
3.1.2 3DM Command Set (0x0C) 30
3.1.3 Estimation Filter Command Set (0x0D) 31
3.1.4 System Command Set (0x7F) 31
3.2 Data
32
3.2.1 IMU Data Set (0x08) 32
3.2.2 GNSS Data Set (0x81) 32
3.2.3 Estimation Filter Data Set (0x82) 32
4. Command Reference 34
4.1 Base Commands
34
4.1.1 Ping (0x01, 0x01) 34
4.1.2 Set To Idle (0x01, 0x02) 35
4.1.3 Get Device Information (0x01, 0x03) 36
4.1.4 Get Device Descriptor Sets (0x01, 0x04) 37
4.1.5 Device Built-In Test (0x01, 0x05) 38
4.1.6 Resume (0x01, 0x06) 40
4.1.7 Get Extended Device Descriptor Sets (0x01, 0x07) 40
4.1.8 GPS Time Update (0x01, 0x72) 41
4.1.9 Device Reset (0x01, 0x7E) 43
4.2 3DM Commands
44
4.2.1 Poll IMU Data (0x0C, 0x01) 44

3DM-GX5-45™GNSS-Aided Inertial Navigation System DCP Manual
4.2.2 Poll GNSS Data (0x0C, 0x02) 45
4.2.3 Poll Estimation Filter Data (0x0C, 0x03) 47
4.2.4 Get IMU Data Base Rate (0x0C, 0x06) 48
4.2.5 Get GNSS Data Base Rate (0x0C, 0x07) 49
4.2.6 Get Estimation Filter Data Base Rate (0x0C, 0x0B) 50
4.2.7 IIMU Message Format (0x0C, 0x08) 51
4.2.8 GNSS Message Format (0x0C, 0x09) 53
4.2.9 Estimation Filter Message Format (0x0C, 0x0A) 55
4.2.10 Enable/Disable Continuous Data Stream (0x0C, 0x11) 57
4.2.11 GNSS Constellation Settings (0x0C, 0x21) 59
4.2.12 GNSS SBAS Settings (0x0C, 0x22) 62
4.2.13 GNSS Assisted Fix Control (0x0C, 0x23) 64
4.2.14 GNSS Assist Time Update (0x0C, 0x24) 65
4.2.15 Device Startup Settings (0x0C, 0x30) 67
4.2.16 Accel Bias (0x0C, 0x37) 68
4.2.17 Gyro Bias (0x0C, 0x38) 69
4.2.18 Capture Gyro Bias (0x0C, 0x39) 70
4.2.19 Magnetometer Hard Iron Offset (0x0C, 0x3A) 71
4.2.20 Magnetometer Soft Iron Matrix (0x0C, 0x3B) 72
4.2.21 Coning and Sculling Enable (0x0C, 0x3E) 74
4.2.22 UART Baud Rate (0x0C, 0x40) 75
4.2.23 Advanced Low-Pass Filter Settings (0x0C, 0x50) 76
4.2.24 Complementary Filter Settings (0x0C, 0x51) 78
4.2.25 Device Status (0x0C, 0x64) 79
4.2.26 Raw RTCM 2.3 Message (0x0C, 0x20) 81
4.3 Estimation Filter Commands
83
4.3.1 Reset Filter (0x0D, 0x01) 83
4.3.2 Set Initial Attitude (0x0D, 0x02) 84
4.3.3 Set Initial Heading (0x0D, 0x03) 85

3DM-GX5-45™GNSS-Aided Inertial Navigation System DCP Manual
4.3.4 Vehicle Dynamics Mode (0x0D, 0x10) 86
4.3.5 Sensor to Vehicle Frame Transformation (0x0D, 0x11) 88
4.3.6 Sensor to Vehicle Frame Offset (0x0D, 0x12) 90
4.3.7 Antenna Offset (0x0D, 0x13) 92
4.3.8 Estimation Control Flags (0x0D, 0x14) 93
4.3.9 GNSS Source Control (0x0D, 0x15) 94
4.3.10 External GNSS Update (0x0D, 0x16) 95
4.3.11 Heading Update Control (0x0D, 0x18) 96
4.3.12 External Heading Update (0x0D, 0x17) 97
4.3.13 External Heading Update with Timestamp (0x0D, 0x1F) 99
4.3.14 Pitch/Roll Aiding Control (0x0D, 0x4B) 100
4.3.15 Altitude Aiding Control (0x0D, 0x47) 101
4.3.16 Auto-Initialization Control (0x0D, 0x19) 102
4.3.17 Magnetometer Noise Standard Deviation (0x0D, 0x42) 103
4.3.18 Gravity Noise Standard Deviation (0x0D, 0x28) 104
4.3.19 Pressure Altitude Noise Standard Deviation (0x0D, 0x29) 105
4.3.20 Accelerometer Noise Standard Deviation (0x0D, 0x1A) 105
4.3.21 Accelerometer Bias Model Parameters (0x0D, 0x1C) 107
4.3.22 Gyroscope Noise Standard Deviation (0x0D, 0x1B) 108
4.3.23 Gyroscope Bias Model Parameters (0x0D, 0x1D) 109
4.3.24 Hard Iron Offset Process Noise (0x0D, 0x2B) 110
4.3.25 Soft Iron Matrix Process Noise (0x0D, 0x2C) 111
4.3.26 Zero Velocity Update (ZUPT) Control (0x0D, 0x1E) 113
4.3.27 Zero Angular Rate Update Control (0x0D, 0x20) 114
4.3.28 Tare Orientation (0x0D, 0x21) 115
4.3.29 Commanded Zero-Velocity Update (0x0D, 0x22) 116
4.3.30 Commanded Zero-Angular Rate Update (0x0D, 0x23) 117
4.3.31 Declination Source (0x0D, 0x43) 118
4.3.32 Gravity Magnitude Error Adaptive Measurement (0x0D, 0x44) 120
4.3.33 Magnetometer Magnitude Error Adaptive Measurement (0x0D, 0x45) 122

3DM-GX5-45™GNSS-Aided Inertial Navigation System DCP Manual
4.3.34 Magnetometer Dip Angle Error Adaptive Measurement (0x0D, 0x46) 124
4.3.35 Magnetometer Capture Auto Calibration (0x0D, 0x27) 126
4.4 System Commands
127
4.4.1 Communication Mode (0x7F, 0x10) 127
4.5 Error Codes
128
5. Data Reference 129
5.1 IMU Data
129
5.1.1 Scaled Accelerometer Vector (0x80, 0x04) 129
5.1.2 Scaled Gyro Vector (0x80, 0x05) 130
5.1.3 Scaled Magnetometer Vector (0x80, 0x06) 130
5.1.4 Scaled Ambient Pressure (0x80, 0x17) 131
5.1.5 Delta Theta Vector (0x80, 0x07) 131
5.1.6 Delta Velocity Vector (0x80, 0x07) 132
5.1.7 CF Orientation Matrix (0x80, 0x09) 132
5.1.8 CF Quaternion (0x80, 0x0A) 134
5.1.9 CF Euler Angles (0x80, 0x0C) 135
5.1.10 CF Stabilized Mag Vector (North) (0x80, 0x10) 136
5.1.11 CF Stabilized Accel Vector (Up) (0x80, 0x11) 137
5.1.12 GPS Correlation Timestamp (0x80, 0x12) 137
5.2 GNSS Data
139
5.2.1 LLH Position (0x81, 0x03) 139
5.2.2 ECEF Position (0x81, 0x04) 140
5.2.3 NED Velocity (0x81, 0x05) 141
5.2.4 ECEF Velocity (0x81, 0x06) 142
5.2.5 DOP Data (0x81, 0x07) 143
5.2.6 UTC Time (0x81, 0x08) 144
5.2.7 GPS Time (0x81, 0x09) 145
5.2.8 Clock Information (0x81, 0x0A) 145
5.2.9 GNSS Fix Information (0x81, 0x0B) 146

3DM-GX5-45™GNSS-Aided Inertial Navigation System DCP Manual
5.2.10 Space Vehicle Information (0x81, 0x0C) 147
5.2.11 Hardware Status (0x81, 0x0D) 148
5.2.12 DGNSS Information (0x81, 0x0E) 149
5.2.13 DGNSS Channel Status (0x81, 0x0F) 150
5.3 Estimation Filter Data
151
5.3.1 Filter Status (0x82, 0x10) 151
5.3.2 GPS Timestamp (0x82, 0x11) 153
5.3.3 LLH Position (0x82, 0x01) 154
5.3.4 LLH Position Uncertainty (0x82, 0x08) 155
5.3.5 NED Velocity (0x82, 0x02) 155
5.3.6 NED Velocity Uncertainty (0x82, 0x09) 156
5.3.7 Orientation, Quaternion (0x82, 0x03) 157
5.3.8 Attitude Uncertainty, Quaternion Elements (0x82, 0x12) 158
5.3.9 Orientation, Euler Angles (0x82, 0x05) 159
5.3.10 Attitude Uncertainty, Euler Angles (0x82, 0x0A) 160
5.3.11 Orientation, Matrix (0x82, 0x04) 161
5.3.12 Compensated Angular Rate (0x82, 0x0E) 162
5.3.13 Gyro Bias (0x82, 0x06) 163
5.3.14 Gyro Bias Uncertainty (0x82, 0x0B) 163
5.3.15 Gyro Scale Factor (0x82, 0x16) 164
5.3.16 Gyro Scale Factor Uncertainty (0x82, 0x18) 164
5.3.17 Compensated Acceleration (0x82, 0x1C) 165
5.3.18 Linear Acceleration (0x82, 0x0D) 166
5.3.19 Accel Bias (0x82, 0x07) 167
5.3.20 Accel Bias Uncertainty (0x82, 0x0C) 167
5.3.21 Accel Scale Factor (0x82, 0x17) 168
5.3.22 Accel Scale Factor Uncertainty (0x82, 0x19) 169
5.3.23 Pressure Altitude (0x82, 0x21) 170
5.3.24 Standard Atmosphere Model (0x82, 0x20) 171

3DM-GX5-45™GNSS-Aided Inertial Navigation System DCP Manual
5.3.25 Gravity Vector (0x82, 0x13) 172
5.3.26 WGS84 Local Gravity Magnitude (0x82, 0x0F) 173
5.3.27 Heading Update Source State (0x82, 0x14) 174
5.3.28 Magnetic Model Solution (0x82, 0x15) 175
5.3.29 Mag Auto Hard Iron Offset (0x82, 0x25) 176
5.3.30 Mag Auto Hard Iron Offset Uncertainty (0x82, 0x28) 176
5.3.31 Mag Auto Soft Iron Matrix (0x82, 0x26) 177
5.3.32 Mag Auto Soft Iron Matrix Uncertainty (0x82, 0x29) 178
5.3.33 GNSS Antenna Offset Correction (0x82, 0x30) 179
5.3.34 GNSS Antenna Offset Correction Uncertainty (0x82, 0x31) 180
6. MIP Packet Reference 181
6.1 Structure
181
6.2 Payload Length Range
181
6.3 MIP Checksum Range
182
6.4 16-bit Fletcher Checksum Algorithm (C Language)
182
7. Advanced Programming 183
7.1 Multiple Commands in a Single Packet
183
7.2 Direct Modes
184
7.3 Internal Diagnostic Functions
185
7.3.1 3DM-GX5-45 Internal Diagnostic Commands 185
7.4 Handling High Rate Data
185
7.4.1 Runaway Latency 185
7.4.2 Dropped Packets 185
7.5 Creating Fixed Data Packet Format
187
7.6 Advanced Programming Models
188
8. Glossary 189

3DM-GX5-45™GNSS-Aided Inertial Navigation System DCP Manual
1. API Introduction
The 3DM- GX5-45 programming interface is comprised of a compact set of setup and control
commands and a very flexible user-configurable data output format. The commands and data are
divided into four command sets and threedata sets corresponding to the internal architecture of the
device. The four command sets consist of a set of “Base” commands (a set that is common across
many types of devices), a set of unified “3DM” (3D Motion) commands that are specific to the
LORD Sensing inertial product line, a set of “Estimation Filter” commands that are specific to
LORD Sensing navigation and advanced AHRS devices, and a set of “System” commands that
are specific to sensor systems comprised of more than one internal sensor block. The three data
sets represent the two types of data that the GX5-45 is capable of producing: “IMU” (Inertial
Measurement Unit) data and “Estimation Filter” (Position, Velocity, and Attitude) data. The type of
estimation filter used in the GX5-45 is an Extended Kalman Filter (EKF).
Base commands Ping, Idle, Resume, Get ID Strings, etc.
3DM commands Poll IMU Data, Estimation Filter Data, etc.
Estimation Filter commands Reset Filter, Sensor to Vehicle Frame Transformation, etc.
System commands Switch Communications Mode, etc.
IMU data Acceleration Vector, Gyro Vector, etc.
Estimation Filter data Position, Velocity, Attitude, Acceleration Estimates, etc.
The protocol is packet based. All commands, replies, and data are sent and received as fields in a
message packet. Commands are all confirmed with an ack/nack (with a few exceptions). The
packets have a descriptor type field based on their contents, so it is easy to identify if a packet
contains commands, replies, IMU data, or Estimation Filter data.