HiPNUC GNSS/INS Command and Programming Manual

Rev 2.0

For HiPNUC GNSS/INS integrated navigation products

Version and Scope

This manual primarily covers the current HiPNUC HIxxN GNSS/INS product range. Physical interfaces and optional features vary by model; refer to the product datasheet and delivered configuration. Commands, registers and some data fields described here may not apply to legacy HI32 products; use the documentation applicable to the delivered device.

When first connecting or troubleshooting, use LOG VERSION to query the product name and firmware version.

Interface	Data and protocols	Applicability
Serial (RS-232 or RS-422)	HI81, GGA, RMC, RTCM3, ASCII configuration commands	Electrical levels and port count depend on the model
Ethernet	HI81, GGA, RMC, ASCII configuration commands	Models equipped with Ethernet only
CAN	SAE J1939	Configurable CAN baud rate and node address
PPS/SYNC	PPS output	Refer to the model-specific datasheet for pins, levels and timing

Quick Start

Connect COM1

1. Check power, COM1 electrical interface, wiring and antenna connections against the product datasheet.
2. Configure the receiver for 115200 bps, 8N1: 8 data bits, no parity, 1 stop bit.
3. Receive COM1 data after power-up. Default output is HI81 binary data at 0.01 s intervals (100 Hz).

Verify HI81 Data

Search for frame header 0x5A 0xA5, extract the complete frame using the payload length, and verify its CRC. Communication is established when:

• Frames with correct CRCs arrive continuously;
• The payload contains HI81 data with tag 0x81;
• The frame period is approximately 10 ms.

An ins_status that has not entered integrated navigation does not mean communication failed. After verifying communication, use the HI81 definition and status guidance below to check installation, antennas, GNSS positioning and navigation status.

Use Other Protocols

Configure GGA, RMC, RTCM3 and J1939 as required by the application. Commands, fields and verification methods are given in their protocol sections; the quick-start procedure does not change default output settings.

Document Revision History

Version	Date	Author	Changes
V2.0	Sep 13, 2026	HiPNUC	Restructured scope, quick start, correction data and protocol guidance
V1.0	Oct 1, 2023	HiPNUC	Initial version

Installation and Coordinate Frames

Body Frame

The device body frame (b-frame) is right-handed: Y points forward along the vehicle, X right and Z up. With the default mounting, the b-frame matches the X / Y / Z markings on the enclosure; for other horizontal mountings, declare where the enclosure arrows point on the vehicle with the mounting code below, and the device aligns its output to the vehicle accordingly.

The device, antennas and vehicle must be rigidly fixed together; relative positions and orientations must not change during operation. Measure lever arms to the antenna phase centers.

HI81 fields ins_lon, ins_lat and ins_msl give the integrated-navigation position of the IMU origin. See the individual GGA and RMC descriptions for their position sources.

Navigation Frame

In integrated-navigation operating modes the navigation frame is fixed at East-North-Up (ENU): X east, Y north, Z up. vel_enu and acc_enu use east, north, up order. Heading is zero at true north and positive clockwise. The output data axes are fixed at Right-Front-Up: CONFIG IMU COORD accepts only 0, and LOG USRCONFIG reads back COORD=0.

ENU Euler angles use the 3-1-2 (Z-X-Y) rotation order: heading, pitch, then roll. The quaternion represents body-to-navigation rotation in W, X, Y, Z order.

Horizontal Mounting Orientation (HIxxN)

For horizontal HIxxN installations, CONFIG IMU URFR <CODE> declares where the X and Y arrows printed on the enclosure point on the vehicle; the Z arrow stays up. Directions are the vehicle's: front is where it drives, right is the driver's right-hand side.

Code	X arrow points	Y arrow points
24	Right (default)	Front
304	Front	Left
214	Back	Right
134	Left	Back

Save, reboot and read back:

CONFIG IMU URFR 24
SAVECONFIG
REBOOT
LOG USRCONFIG

Dual-Antenna Baseline and Lever Arms

A is the primary positioning antenna and B is the dual-antenna heading antenna. Do not interchange connectors or ANTA and ANTB coordinates. These are the position vectors from the IMU origin to the phase centers of antennas A and B, respectively, in the device body frame (the vehicle's right, front and up after the mounting correction: X right, Y front, Z up) and in meters. The baseline vector is ANTB - ANTA.

Set antenna A's lever arm:

SETBASELINE ANTA <X,Y,Z>

Set antenna B's lever arm:

SETBASELINE ANTB <X,Y,Z>

Separate parameters with commas, without spaces. Each antenna lever-arm length must not exceed 1000 m; baseline length must be 0.05–1000 m.

For example, A and B at (-1.5, -1.2, -0.3) and (1.5, -1.2, -0.3) relative to the IMU:

SETBASELINE ANTA -1.5,-1.2,-0.3
SETBASELINE ANTB 1.5,-1.2,-0.3
SAVECONFIG
REBOOT

After rebooting, send LOG INSCONFIG and check ANTA and ANTB against the actual installation. Accurate lever arms reduce errors caused by different antenna and IMU positions during vehicle rotation.

The lever arms can also be read and written as registers: ANTA X / Y / Z at 0x03D0 / 0x03D2 / 0x03D4 and ANTB at 0x03D6 / 0x03D8 / 0x03DA, each value the 32-bit pattern of an IEEE-754 single-precision float, in meters. Over J1939, write them one at a time as in Configure J1939; they take effect after saving and rebooting. A value whose magnitude exceeds 1000 m is rejected; writing one value at a time does not check the spacing between the antennas, so the host should confirm it is at least 0.05 m before writing. The "Installation" page of the CHCenter configuration dialog reads and writes the lever arms directly.

Common Operations

Configuration uses ASCII commands. End every command with carriage return and line feed \r\n. Success normally returns OK; ERR or text beginning with ERROR indicates failure. When communication settings change, the device reboots or a timeout occurs, use readback and valid data as final verification.

Command Overview

Command	Purpose
REBOOT	Reboot the device
LOG	Query information or control a specified serial port's output
CONFIG	Configure navigation operating parameters
UNLOGALL	Disable all periodic messages on the current serial port
SAVECONFIG	Save configuration that must survive power loss
FRESET	Restore default user configuration
SETBASELINE	Set A and B antenna lever arms
SERIALCONFIG	Set a specified serial port's baud rate

LOG and SERIALCONFIG accept a target port after the command, for example LOG COM2 COMCONFIG or SERIALCONFIG COM2 460800. Without COMx, they apply to the port receiving the command. Available ports depend on the model.

Reboot

REBOOT immediately restarts the device, equivalent to cycling power. Run SAVECONFIG first for parameters that must be retained.

Query and Control Serial Output

Pause or Resume Output

• LOG ENABLE: resume output on the port receiving the command;
• LOG DISABLE: pause output on the port receiving the command.

These commands only control that port's runtime output and do not change other serial-port settings.

Query Version

LOG VERSION queries product name and firmware version. PNAME, APP_VER and BL_VER identify the product name, application firmware version and Bootloader version. Responses may include serial number, build date and other information; do not assume a fixed field or line count.

Query Serial Configuration

LOG [COMx] COMCONFIG queries baud rate and message periods on the current or specified port. Returned ONTIME values are milliseconds:

COM=COM1
BAUD=115200
MSG=HI81, ONTIME=10

The device may also list other messages supported by that port.

Query Dual-Antenna Configuration

LOG INSCONFIG queries A and B antenna lever arms. Principal fields:

ANTA=0.000,0.000,0.200
ANTB=0.000,1.000,0.200

Additional fields may be returned; do not assume a fixed field or line count.

Configure Periodic Messages

Syntax: LOG [COMx] <MSG> ONTIME <PERIOD>.

Parameter	Description
MSG	HI81, GGA or RMC
PERIOD	Period in seconds; common supported range 0–32.767 s; 0 disables the message

Example:

LOG HI81 ONTIME 0.01
SAVECONFIG

This sets the current port's HI81 period to 10 ms (100 Hz). GGA and RMC commonly use 0.1 or 1 second. Calculate the combined bandwidth required by all enabled messages, including serial framing, and leave headroom below the port's baud rate. OK means the configuration was accepted; it does not guarantee the actual output period. Periodic messages may be skipped when bandwidth is insufficient or transmission is congested.

Configure the Navigation Operating Mode

Syntax: CONFIG MODEL <MODEL>.

MODEL	Description
CAR	Vehicle mode with vehicle motion constraints; factory default
SHIP	Marine mode
PLANE	Aircraft mode without vehicle motion constraints

Save and reboot:

CONFIG MODEL CAR
SAVECONFIG
REBOOT

Configure NTRIP

Only models with a supported network interface or associated DTU can use NTRIP directly. Refer to the product datasheet and delivered configuration for wiring, network access and associated equipment.

CONFIG NTRIP <SERVER> <PORT> <MOUNTPOINT> <USERNAME> <PASSWORD>

Parameter	Description
SERVER	CORS/NTRIP service domain name or IP address
PORT	Service port
MOUNTPOINT	Mountpoint
USERNAME	Account username
PASSWORD	Account password

Credential Security

LOG NTRIPCONFIG may return usernames and passwords. Remove credentials before saving terminal logs, taking screenshots or requesting technical support.

The address and account below illustrate syntax only:

CONFIG NTRIP caster.example.com 2101 MOUNT1 demo_user demo_password
SAVECONFIG
REBOOT

After rebooting, read back server, port, mountpoint and account settings with LOG NTRIPCONFIG. Check HI81 GNSS positioning status to confirm RTK. Acquisition time depends on antenna environment, correction service, network quality and base-station distance.

Disable All Periodic Messages on the Current Port

UNLOGALL disables all periodic messages on the port receiving the command, including default HI81 output. Other ports are unaffected. Run SAVECONFIG afterward if the change must survive power loss.

Save Configuration

Run SAVECONFIG after changes that must be retained. Run REBOOT afterward only for settings explicitly documented as requiring a reboot.

Restore Defaults

Record Settings Before Restoring

FRESET overwrites user configuration with defaults. Record required lever arms, network, output and bus settings first; redact NTRIP credentials in terminal logs.

Use FRESET only for configuration problems unresolved by ordinary troubleshooting:

1. Record required settings, then send FRESET.
2. Wait for restart; cycle power if communication does not return.
3. Reconnect to COM1 at 115200 bps, 8N1 and verify continuous 100 Hz HI81 output.
4. Read back configuration, restore application settings, and verify navigation and communication data again.

If some settings are not back at their defaults after the restart (for example, no HI81 output), do not send FRESET again: set the missing items by hand as in step 4 (for example, LOG HI81 ONTIME 0.01), then run SAVECONFIG.

Change the Serial Baud Rate

Supported values are 115200, 460800 and 921600:

SERIALCONFIG [COMx] <BAUD>

1. Send LOG [COMx] COMCONFIG to record the target port's current settings.
2. Send SERIALCONFIG [COMx] <BAUD>. If changing the port receiving the command, switch the host to the new rate after receiving OK.
3. Send SAVECONFIG through a port that still communicates.
4. Read LOG [COMx] COMCONFIG to check BAUD against the target; verify valid data on that port.

Serial and Network Protocols

Introduction

Serial ports and applicable network interfaces carry NMEA 0183 ASCII and HiPNUC binary messages. Both may share one port; identify their start markers separately as $ and 0x5A 0xA5.

Transport Interfaces

• RS-232 and RS-422 use the same serial format. Device and receiver baud rates must match; the default is 115200 bps.
• Some models have Ethernet and obtain an IP address through DHCP. The default connection uses TCP port 5944. Once connected, command and data formats match the serial interface. Network capabilities depend on the datasheet and delivered configuration.

NMEA Messages (ASCII)

NMEA messages start with $, end with * and a two-digit hexadecimal checksum, then carriage return and line feed 0x0D 0x0A:

$<Talker><Type>,<Field1>,<Field2>,...*<Checksum><CR><LF>

Field	Description
$	Start character, ASCII 0x24
Talker	Two-character identifier; current products default to GP. Identify data by message type without restricting the satellite system based on this identifier
Type	Three-character type; this manual documents GGA and RMC
,	Separator, ASCII 0x2C; retain separators for empty fields
*	Separates data and checksum
Checksum	Bytewise XOR of all characters between $ and *, as two uppercase hexadecimal ASCII characters
<CR><LF>	Terminator, ASCII 0x0D 0x0A

NMEA Message List

Message	Description	Data source
GGA	Position, UTC time, fix quality and satellites used	Position solution
RMC	Time, position, ground speed and course over ground	Position and velocity solution

GGA and RMC position sources vary by product implementation: GNSS antenna position or integrated-navigation result. For consistent integrated position, velocity and attitude referenced to the IMU origin, parse HI81.

When external time changes, time fields may temporarily be invalid. Check validity continuously and confirm the new epoch before using absolute time.

GGA

Receiver time, position and positioning-related data.

Treat the fix as invalid if quality is empty or 0; do not rely on fixed placeholder values in other fields. Empty time means invalid UTC. The sentence may still output at its configured period.

$GPGGA,062134.00,2813.9908005,N,11252.6285300,E,1,28,0.5,83.684,M,-17.038,M,0.0,0000*54

ID	Example	Format	Description
1	$GPGGA	Header
2	062134.00	hhmmss.ss	UTC time
3	2813.9908005	ddmm.m…	Latitude: first two digits degrees, remainder minutes; 0°–90°
4	N	-	Latitude direction: N north, S south
5	11252.6285300	dddmm.m…	Longitude: first three digits degrees, remainder minutes; 0°–180°
6	E	-	Longitude direction: E east, W west
7	1	x	0 invalid; 1 single-point or PPP; 2 pseudorange differential; 4 RTK fixed; 5 RTK float
8	28	xx	Satellites used for positioning
9	0.5	x.x	HDOP: horizontal dilution of precision
10	83.684	x.xxx	Altitude above mean sea level
11	M	U	Altitude unit: m
12	-17.038	x.xxx	Geoid undulation: WGS84 ellipsoidal height minus altitude above mean sea level
13	M	U	Geoid undulation unit: m
14	0.0	x.x	Differential age in s
15	0000	xxxx	Differential station ID
16	54	hh	Checksum

Latitude and longitude use degrees and minutes, without a separate seconds field. Convert with decimal degrees = degrees + minutes / 60, then apply the sign from N/S/E/W. Decimal precision may vary by firmware; parse comma-separated decimal values, not fixed-width slices.

RMC

Recommended minimum navigation data.

Treat the fix as invalid if positioning status is empty or V; do not rely on fixed placeholder values for position, speed or course. Empty time or date means invalid UTC. The sentence may still output at its configured period.

$GPRMC,020550.00,A,2813.9891299,N,11252.6278784,E,0.03,315.70,161117,0.0,E,A,V*49

ID	Example	Format	Description
1	$GPRMC	Header	Start character and message type
2	020550.00	hhmmss.ss	UTC time
3	A	x.x	Positioning status: A valid, V invalid
4	2813.9891299	ddmm.m…	Latitude format as in GGA
5	N	-	Latitude direction as in GGA
6	11252.6278784	dddmm.m…	Longitude format as in GGA
7	E	-	Longitude direction as in GGA
8	0.03	x.xx	Horizontal ground speed in knots
9	315.70	x.xx	Course over ground, true-north reference, positive clockwise, 0°–360°
10	161117	ddmmyy	Date: day, month, year
11	0.0	x.x	Reserved; ignore
12	E	-	Reserved; ignore
13	A	-	Mode: N invalid; A autonomous; D differential; E estimated; F RTK float; R RTK fixed
14	V	-	Extended status; do not use alone to determine fix validity
15	49	hh	Checksum

Determine RMC fix validity primarily from field 3 (A/V), together with field 13's mode. Field 14 is not an independent indication of validity.

HiPNUC Binary Messages

HI81 is the common binary output for HiPNUC GNSS/INS products. Serial format is 8N1; physical interfaces depend on the datasheet.

Unless stated otherwise, integer fields' physical values equal raw values multiplied by scale factors.

Frame Format

COM1 defaults to 100 Hz HI81. Multi-byte integers and CRC are little-endian.

Frame order	Value	Length (bytes)	Description
Sync byte 1	0x5A	1	Fixed
Sync byte 2	0xA5	1	Fixed
Payload length	0x0068 for HI81	2	Payload only, excluding sync, length and CRC
CRC	-	2	Little-endian; skip this field during calculation
Payload	First byte 0x81	104 for HI81	Fields below

A complete HI81 frame is 110 bytes: CRC at frame offsets 4–5, payload from offset 6. Table offsets below start at the first payload byte, 0x81.

Payload Content

Integrated Navigation Data (HI81)

HI81 payload length is fixed at 104 bytes.

Integrated Navigation Status

ins_status is the common field identifying the navigation operating phase:

Value	State	Meaning
0	Invalid	Information required for initialization not yet obtained
1	Aligning	Initialization started, but integrated navigation not yet active
3	Integrated navigation	Initialized with valid GNSS aiding
6	Inertial dead reckoning	Initialized, but GNSS aiding currently unavailable; propagating inertially

Offset	Name	Type	Size (bytes)	Unit	Scale	Description
0	tag	uint8_t	1	-	-	Packet tag: 0x81
1	status	uint16_t	2	-	-	Reserved; do not interpret
3	ins_status	uint8_t	1	-	-	Navigation status as above
4	gpst_wn	uint16_t	2	week	1	GPS week
6	gpst_tow	uint32_t	4	s	0.001	GPS time of week
10	reserved	uint8_t[2]	2	-	-	Reserved; ignore
12	gyr_b	int16_t[3]	6	rad/s	0.001	Body X, Y, Z angular rate; factory-calibrated IMU measurements
18	acc_b	int16_t[3]	6	m/s²	0.0048828	Body X, Y, Z acceleration; factory-calibrated IMU measurements
24	mag_b	int16_t[3]	6	μT	0.030517	Body X, Y, Z magnetic field; factory-calibrated IMU measurements
30	air_pressure	int16_t	2	Pa	1	Actual pressure = field value + 100000 Pa; 2000 means 102000 Pa
32	reserved	uint8_t[2]	2	-	-	Reserved; ignore
34	temperature	int8_t	1	°C	1	Temperature
35	utc_year	uint8_t	1	year	1	UTC year minus 2000; 24 means 2024
36	utc_month	uint8_t	1	month	1	UTC month
37	utc_day	uint8_t	1	day	1	UTC day
38	utc_hour	uint8_t	1	h	1	UTC hour
39	utc_min	uint8_t	1	min	1	UTC minute
40	utc_msec	uint16_t	2	s	0.001	UTC seconds and milliseconds
42	roll	int16_t	2	deg	0.01	Roll, -180°–180°
44	pitch	int16_t	2	deg	0.01	Pitch, -90°–90°
46	yaw	uint16_t	2	deg	0.01	Heading, zero at true north, positive clockwise, 0°–360°
48	quat	int16_t[4]	8	-	0.0001	Body-to-navigation quaternion, W, X, Y, Z
56	ins_lon	int32_t	4	deg	1e-7	Integrated-navigation longitude
60	ins_lat	int32_t	4	deg	1e-7	Integrated-navigation latitude
64	ins_msl	int32_t	4	m	0.001	Integrated-navigation altitude above mean sea level
68	pdop	uint8_t	1	-	0.1	GNSS position dilution of precision
69	hdop	uint8_t	1	-	0.1	GNSS horizontal dilution of precision
70	solq_pos	uint8_t	1	-	-	GNSS fix quality: 0 invalid; 1 single-point or PPP; 2 pseudorange differential; 4 RTK fixed; 5 RTK float
71	nv_pos	uint8_t	1	-	-	Satellites used for GNSS positioning
72	solq_heading	uint8_t	1	-	-	Dual-antenna heading quality: 4 fixed; otherwise unavailable
73	nv_heading	uint8_t	1	-	-	Satellites used for dual-antenna heading
74	diff_age	uint8_t	1	s	1	RTK differential age
75	undulation	int16_t	2	m	0.01	WGS84 ellipsoidal height minus altitude above mean sea level
77	reserved	uint8_t	1	-	-	Reserved; ignore
78	vel_enu	int16_t[3]	6	m/s	0.01	Navigation-frame east, north, up velocity
84	acc_enu	int16_t[3]	6	m/s²	0.0048828	Navigation-frame east, north, up acceleration
90	reserved	uint8_t[14]	14	-	-	Reserved; ignore

Use gpst_wn, gpst_tow and UTC fields as absolute time only after obtaining a valid GNSS/UTC epoch. Do not rely on fixed placeholders for invalid time; HI81 may still output at the configured period.

Skip reserved fields by their fixed lengths; their values must not change parsing layout.

CRC

HI81 uses CRC-16/XMODEM: polynomial 0x1021, initial value 0x0000, no input/output reflection and no final XOR. It covers header, length and payload, excluding the CRC field itself.

static void crc16_update(uint16_t *currentCrc, const uint8_t *src,
                         uint32_t lengthInBytes)
{
    uint32_t crc = *currentCrc;
    for (uint32_t j = 0; j < lengthInBytes; ++j)
    {
        crc ^= (uint32_t)src[j] << 8;
        for (uint32_t i = 0; i < 8; ++i)
        {
            uint32_t temp = crc << 1;
            if (crc & 0x8000)
                temp ^= 0x1021;
            crc = temp;
        }
    }
    *currentCrc = (uint16_t)crc;
}

uint16_t crc = 0;
crc16_update(&crc, frame, 4);       /* 5A A5 LEN_L LEN_H */
crc16_update(&crc, frame + 6, 104); /* HI81 payload */

uint16_t receivedCrc = (uint16_t)frame[4] | ((uint16_t)frame[5] << 8);
bool crcOk = (crc == receivedCrc);

RTCM3 Correction Data

RTCM3 carries GNSS corrections. Keep COM1's default HI81 output and use an available COM2 for RTCM3. Base-station output and rover correction input are separate workflows.

Rover Correction Input

Feed the correction source's raw RTCM3 bytes directly into COM2, without ASCII commands, line terminators or other wrappers. The source and COM2 baud rates must match.

Use one correction source at a time. Continuously monitor HI81: diff_age should update with corrections; solq_pos of 4 (RTK fixed) or 5 (RTK float) indicates the position solution is using RTK.

Base-Station RTCM3 Output

Record the current mode and port configuration before switching to base-station mode. On COM2, run:

UNLOGALL
CONFIG MODEL BASE
LOG RTCM3 ONTIME 1
SAVECONFIG
REBOOT

The nonzero value in LOG RTCM3 ONTIME 1 only enables RTCM3 forwarding; it does not set the RTCM generation rate. The internal GNSS module generates these messages, which the device forwards:

RTCM3 message	Rate
1005	1 Hz
1074	1 Hz
1094	1 Hz
1124	1 Hz

After reboot, verify complete RTCM3 frames with correct checksums on COM2. To return to integrated navigation, select CAR, SHIP or PLANE and restore required port outputs.

CAN Interface: SAE J1939

CAN-equipped INS products use SAE J1939, default baud rate 500 kbit/s and device address 0x08. Interface capabilities depend on the model and delivered configuration.

Positions in FF10 and FF14 refer to the IMU origin, as in HI81.

J1939 uses a 29-bit extended ID: priority P (3 bits), reserved R (1 bit), data page DP (1 bit), PDU format PF (8 bits), PDU specific PS (8 bits), source address SA (8 bits). Here measurement PGNs have PF=0xFF and are PDU2 broadcasts: PS is the PGN's low 8 bits, SA the device address.

Item	Convention
Communication mode	Periodic measurement PGN broadcasts
Data length	All measurement PGNs in this section are 8 bytes
PF	0xFF
Priority	3
Default source address	0x08
Data format	Multi-byte values little-endian; signed integers unless explicitly unsigned or status fields

Each PGN period is independently configured; defaults may vary by product. Use readback and actual received periods, not an assumed common default.

PGN Message List

PGN 65296 (FF10): Latitude and Longitude

Default-address CAN ID: 0x0CFF1008.

SPN	Bytes	Description
Latitude	0–3	int32_t, deg, scale 1e-7
Longitude	4–7	int32_t, deg, scale 1e-7

PGN 65300 (FF14): Altitude and Differential Age

Default-address CAN ID: 0x0CFF1408.

SPN	Bytes	Description
Altitude above mean sea level	0–3	int32_t, m, scale 0.01
Geoid undulation	4–5	int16_t, m, scale 0.01
Differential age	6–7	int16_t, s, scale 0.01

PGN 65304 (FF18): Fix Status and Satellite Counts

Default-address CAN ID: 0x0CFF1808.

SPN	Bytes	Description
GNSS fix quality	0	0 invalid; 1 single-point or PPP; 2 pseudorange differential; 4 RTK fixed; 5 RTK float
Dual-antenna heading quality	1	4 fixed; otherwise unavailable
Positioning satellites	2	Satellites used for GNSS positioning
Heading satellites	3	Satellites used for dual-antenna heading
ins_status	4	Same navigation-status definition as HI81
Reserved	5–7	Ignore

PGN 65318 (FF26): Velocity

Default-address CAN ID: 0x0CFF2608.

SPN	Bytes	Description
East velocity	0–1	int16_t, m/s, scale 0.01
North velocity	2–3	int16_t, m/s, scale 0.01
Up velocity	4–5	int16_t, m/s, scale 0.01
Horizontal ground speed	6–7	int16_t, m/s, scale 0.01

PGN 65327 (FF2F): Time

Default-address CAN ID: 0x0CFF2F08.

SPN	Bytes	Description
UTC year	0	Year minus 2000; 24 means 2024
UTC month	1
UTC day	2
UTC hour	3
UTC minute	4
UTC second	5
UTC milliseconds	6–7	uint16_t, ms, scale 1

Use FF2F as UTC only with a plausible, nonzero date. Ignore it until absolute time is valid; do not rely on invalid-time placeholder values.

PGN 65332 (FF34): Acceleration

Default-address CAN ID: 0x0CFF3408.

SPN	Bytes	Description
Acceleration X	0–1	int16_t, g, scale 0.00048828
Acceleration Y	2–3	int16_t, g, scale 0.00048828
Acceleration Z	4–5	int16_t, g, scale 0.00048828
Reserved	6–7	Ignore

PGN 65335 (FF37): Angular Rate

Default-address CAN ID: 0x0CFF3708.

SPN	Bytes	Description
Angular rate X	0–1	int16_t, deg/s, scale 0.061035
Angular rate Y	2–3	int16_t, deg/s, scale 0.061035
Angular rate Z	4–5	int16_t, deg/s, scale 0.061035
Reserved	6–7	Ignore

PGN 65341 (FF3D): Roll and Pitch

Default-address CAN ID: 0x0CFF3D08.

SPN	Bytes	Description
Roll	0–3	int32_t, deg, scale 0.001
Pitch	4–7	int32_t, deg, scale 0.001

PGN 65345 (FF41): Heading

Default-address CAN ID: 0x0CFF4108.

SPN	Bytes	Description
Heading (clockwise)	0–3	uint32_t, zero at true north, positive clockwise, 0°–360°, deg, scale 0.001
Reserved	4–7	Ignore

PGN 65347 (FF43): Temperature

Default-address CAN ID: 0x0CFF4308.

SPN	Bytes	Description
Temperature	0–1	int16_t, °C, scale 0.01
Reserved	2–7	Ignore

Configure J1939

Configuration uses PDU1 PGN 0xEF00, with the host fixed at source address 0x55. At default device address 0x08:

• Host request ID: 0x0CEF0855, destination device 0x08, source host 0x55;
• Device response ID: 0x0CEF5508, destination host 0x55, source device 0x08.

Configuration frames are 8 bytes:

Field	Bytes	Description
ADDR	0–1	16-bit register address, little-endian
CMD	2	0x06 write, 0x03 read
STATUS	3	Reserved; host sends 0x00
VAL	4–7	32-bit value, little-endian; send 0 for reads

Successful ordinary writes echo the request; successful reads return the current VAL. Invalid addresses or parameters may receive no response. Set a timeout rather than waiting indefinitely.

Configuration Registers

Address	Object	Value
0x0110	FF10 latitude/longitude period	0 off; 10–1000 ms
0x0114	FF14 altitude/differential age period	0 off; 10–1000 ms
0x0118	FF18 fix-status period	0 off; 10–1000 ms
0x0126	FF26 velocity period	0 off; 10–1000 ms
0x012F	FF2F time period	0 off; 10–1000 ms
0x0134	FF34 acceleration period	0 off; 10–1000 ms
0x0137	FF37 angular-rate period	0 off; 10–1000 ms
0x013D	FF3D roll/pitch period	0 off; 10–1000 ms
0x0141	FF41 heading period	0 off; 10–1000 ms
0x0143	FF43 temperature period	0 off; 10–1000 ms
0x009A	CAN baud rate	0 1000 kbit/s; 1 800 kbit/s; 2 500 kbit/s; 3 250 kbit/s; 4 125 kbit/s
0x009C	Device address	1–64, default 8
0x009D	J1939 periodic-output master switch	0 off; 1 on
0x03D0–0x03DA	Antenna lever arms ANTA, ANTB	One address per axis, float bit pattern, in m; see Dual-Antenna Baseline and Lever Arms; takes effect after saving and rebooting
0x0000	Control	0x00000000 save; 0x000000FF reboot

For example, set FF37 angular-rate period to 100 ms:

ID   = 0x0CEF0855
DATA = 37 01 06 00 64 00 00 00

Read 0x0137 to verify:

ID   = 0x0CEF0855
DATA = 37 01 03 00 00 00 00 00

Disable all J1939 periodic output:

ID   = 0x0CEF0855
DATA = 9D 00 06 00 00 00 00 00

Set VAL to 01 00 00 00 to re-enable. Read back the target register, then write 0x00000000 to 0x0000 to save and 0x000000FF to reboot. Verify actual CAN IDs and periods. After a baud-rate change, verify with the new rate after reboot. Reboot may occur before its response; valid messages received again with new parameters establish success.

Status and Troubleshooting

Integrated-Navigation Initialization

Working communication does not mean navigation is initialized. The device first establishes position from a valid GNSS fix, then initializes using fixed dual-antenna heading or velocity heading from sustained motion. Without dual-antenna heading, maintain steady motion under good satellite conditions and check ins_status.

Throughout initialization and operation, ins_status means: 0 invalid, 1 aligning, 3 integrated navigation, 6 inertial dead reckoning. State 6 continues outputting navigation data, but errors accumulate with outage duration and motion conditions. Integrated navigation resumes automatically when GNSS aiding is valid again.

Troubleshooting Order

Symptom	Check first	Assessment and action
No HI81 on COM1	Power, levels, TX/RX, common ground, 115200 8N1	Verify continuous complete 110-byte frames starting 0x5A 0xA5 with correct CRC; use LOG COMCONFIG to check settings if needed
ins_status remains 0 or 1	Antenna A sky view, solq_pos, satellite count, mode, lever arms	Also check A/B connections, baseline direction and solq_heading=4 on dual-antenna models; without fixed heading, maintain steady motion for heading initialization
ins_status changes 3 to 6	solq_pos, differential age, obstructions, GNSS continuity	With NTRIP, also check network, server, mountpoint and account; observe return to 3 when valid aiding resumes
Incorrect heading direction or large offset	Device Y forward, A/B order, ANTA, ANTB, rigid mounting	Verify true-north zero and clockwise-positive; dual-antenna heading requires solq_heading=4
RTK will not fix	Antenna conditions, corrections, diff_age, network, NTRIP	Confirm continuous correction reception, then account, base distance and obstructions; a fixed waiting time is not a success criterion
No J1939 messages	CAN availability, 500 kbit/s, 29-bit extended frames, termination, address, periods	Read target PGN period, then check ID against actual device address; do not assume identical defaults across firmware

Before Contacting Technical Support

Prepare product name and APP_VER, LOG COMCONFIG, LOG INSCONFIG, and a short raw HI81 or CAN capture. For heading or RTK issues, also describe antenna installation, satellite conditions, differential age and network status.

Firmware Upgrade and Technical Support

Firmware Upgrade

Contact technical support with the product model and the LOG VERSION output so that the applicable .hex file can be confirmed; do not use firmware for another model. Select the file in CHCenter under Tools > Firmware Upgrade, connect the device and start upgrading. Keep power and communication stable. Reconnect afterward and check APP_VER with LOG VERSION.

Development Resources

C/C++, Python, STM32, ROS and DBC resources are under SDK and Development Resources. This manual defines the protocols.

Technical Support

Latest documentation and support channels:

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