Huace Navigation Technology A02003 GNSS receiver User Manual SY4 A02003 User Manual Rev2

Download:
Mirror Download [FCC.gov]
Document ID	2738827
Application ID	SOvUQWi9vjUl7LIfU/imtg==
Document Description	User Manual
Short Term Confidential	No
Permanent Confidential	No
Supercede	No
Document Type	User Manual
Display Format	Adobe Acrobat PDF - pdf
Filesize	130.15kB (1626844 bits)
Date Submitted	2015-09-08 00:00:00
Date Available	2015-09-08 00:00:00
Creation Date	2015-09-02 18:21:19
Producing Software	Acrobat Distiller 9.5.5 (Windows)
Document Lastmod	2015-09-02 18:21:19
Document Title	Microsoft Word - SY4-A02003__User?Manual Rev2.doc
Document Creator	PScript5.dll Version 5.2.2
Document Author:	jiaxing.ye

Safety Information
il
CHC® N72™ GNSS Reference
Receiver
Revision 1.0
January 2015
Copyright
Copyright 2009‐2015 CHC | Shanghai HuaCe
Navigation Technology Ltd. All rights reserved. The
CHC are trademark of Shanghai HuaCe Navigation
Technology Limited. All other trademarks are the
property of their respective owners.
Trademarks
All product and brand names mentioned in this
publication are trademarks of their respective
holders.
Safety Warnings
The Global Positioning System (GPS) is operated by
the U.S. Government, which is solely responsible
for the accuracy and maintenance of the GPS
network. Accuracy can also be affected by poor
satellite geometry and obstructions, like buildings
and heavy canopy.
try to correct the interference by one or more of
the following measures:
—Reorient or relocate the receiving antenna.
—Increase the separation between the equipment
and receiver.
—Connect the equipment into an outlet on a
circuit different from that to which the receiver is
connected.
—Consult the dealer or an experienced radio/TV
technician for help.
N72 GNSS Reference Receiver User Guide –
Revision 1.0 January 2015
FCC interference statement
This equipment has been designed to comply with
the limits for a Class B digital device, pursuant to
part 15 of the FCC Rules in the Portable Mode.
These limits are designed to provide reasonable
protection against harmful interference in a
residential installation.
Operation is subject to the following two
conditions: (1) this device may not cause harmful
interference and (2) this device must accept any
interference received, including interference that
may cause undesired operation.
Note:
THE GRANTEE IS NOT RESPONSIBLE FOR ANY
CHANGES OR MODIFICATIONS NOT EXPRESSLY
APPROVED BY THE PARTY RESPONSIBLE FOR
COMPLIANCE. SUCH MODIFICATIONS COULD VOID
THE USER’S AUTHORITY TO OPERATE THE
EQUIPMENT
This product has been tested and found to comply
with the limits for Part 15 of the FCC Rules. These
limits are designed to provide reasonable
protection against harmful interference in a
residential installation. This product generates,
uses, and can radiate radio frequency energy and,
if not installed and used in accordance with the
instructions, may cause harmful interference to
radio communications. However, there is no
guarantee that interference will not occur in a
particular installation. If this product does cause
harmful interference to radio or television
reception, which can be determined by turning the
equipment off and on, the user is encouraged to
N72 GNSS Reference Receiver User Guide
 Page 1
SAFETY INFORMATION
Before you use your CHC® N72™ GNSS reference receiver, make sure that
you have read and understood all safety requirements.
REGULATIONS AND SAFETY
The receiver contains an internal wireless modem for communicating signals
through Bluetooth® wireless technology or through an external data
communications radio. Regulations regarding the use of the wireless modem
vary greatly from country to country. In some countries, the unit can be used
without obtaining an end‐user license. Other countries require end‐user
licensing. For licensing information, consult your local CHC dealer.
Before operating a N72 GNSS reference receiver, determine if authorization
or a license to operate the unit is required in your country. It is the
responsibility of the end‐user to obtain an operator's permit or license for
the receiver for the location or country of use.
TYPE APPROVAL
Type approval, or acceptance, covers technical parameters of the equipment
related to emissions that can cause interference. Type approval is granted to
the manufacturer of the transmission equipment, independent from the
operation or licensing of the units. Some countries have unique technical
requirements for operation in particular radio modem frequency bands. To
comply with those requirements, CHC may have modified your equipment to
be granted Type approval. Unauthorized modification of the units voids the
Type approval, the warranty, and the operational license of the equipment.
EXPOSURE TO RADIO FREQUENCY RADIATION
Safety. Exposure to RF energy is an important safety consideration. The FCC
has adopted a safety standard for human exposure to radio frequency
electromagnetic energy emitted by FCC regulated equipment. Proper use of
this radio modem results in exposure below government limits. The
following precautions are recommended:

Do not operate the transmitter when someone is 20 cm (7.8 inches) of
the antenna.

Do not operate the transmitter unless all RF connectors are secure and
any open connectors are correctly terminated.

Do not operate the equipment near electrical blasting caps or in an
N72 GNSS Reference Receiver User Guide
 Page 2
Safety Information
explosive atmosphere.

All equipment must be correctly grounded for safe operation.

All equipment should be serviced only by a qualified technician.
BATTERY SAFETY
WARNING – Do not damage the rechargeable Lithium‐ion battery. A
damaged battery can cause an explosion or fire, and can result in personal
injury and/or property damage. To prevent injury or damage:
– Do not use or charge the battery if it appears to be damaged. Signs
of damage include, but are not limited to, discoloration, warping,
and leaking battery fluid.
– Do not expose the battery to fire, high temperature, or direct
sunlight.
– Do not immerse the battery in water.
– Do not use or store the battery inside a vehicle during hot weather.
– Do not drop or puncture the battery.
– Do not open the battery or short‐circuit its contacts.
WARNING – Avoid contact with the rechargeable Lithium‐ion battery if it
appears to be leaking. Battery fluid is corrosive, and contact with it can result
in personal injury and/or property damage. To prevent injury or damage:
– If the battery leaks, avoid contact with the battery fluid.
– If battery fluid gets into your eyes, immediately rinse your eyes with
clean water and seek medical attention. Do not rub your eyes!
– If battery fluid gets onto your skin or clothing, immediately use
clean water to wash off the battery fluid.
WARNING – Charge and use the rechargeable Lithium‐ion battery only in
strict accordance with the instructions. Charging or using the battery in
unauthorized equipment can cause an explosion or fire, and can result in
personal injury and/or equipment damage. To prevent injury or damage:
– Do not charge or use the battery if it appears to be damaged or
leaking.
– Charge the Lithium‐ion battery only in a CHC product that is
specified to charge it.
– Discontinue charging a battery that gives off extreme heat or a
burning odor.
– Use the battery only in CHC equipment that is specified to use it.
– Use the battery only for its intended use and according to the
instructions in the product documentation.
N72 GNSS Reference Receiver User Guide
 Page 3
Safety Information
DC POWER SUPPLY SAFETY
WARNING – When DC voltage is applied to this receiver through COM 1 or
COM 2 (Lemo connectors), the DC voltage must be limited to no more than
36 V DC +0% under both normal and single fault conditions. If the
recommended input voltage is exceeded, the receiver may present an
electrical hazard.
WET LOCATION SAFETY
WARNING – This receiver is not intended to be used in a wet location, or a
location that may become wet, when it is powered by the external DC power
supply. Use the receiver in a wet location only when operating it on its own
internal battery.
WARNING – The external power adapter and its associated power cord and
plug are not intended to be installed outdoors, or in a wet location.
WARNING – Do not power the receiver through external power when
operating in a wet environment or an environment that may become wet.
The power input connections must be sheltered.
N72 GNSS Reference Receiver User Guide
 Page 4
CONTENTS
Safety Information ........................................................................................................................................... 2
Regulations and safety............................................................................................................................. 2
Type approval .......................................................................................................................................... 2
Exposure to radio frequency radiation .................................................................................................... 2
Battery safety........................................................................................................................................... 3
DC power supply safety ........................................................................................................................... 4
Wet location safety .................................................................................................................................. 4
1. Introduction ................................................................................................................................................. 7
1.1. About the receiver ............................................................................................................................ 7
1.2. Technical support .............................................................................................................................. 7
1.3. Disclaimer ......................................................................................................................................... 8
1.4. Your comments ................................................................................................................................. 8
2. Overview ...................................................................................................................................................... 9
2.1. Receiver framework .......................................................................................................................... 9
2.1.1. The network appliance concept .......................................................................................... 10
2.2. Receiver services............................................................................................................................. 10
2.3. Receiver features ............................................................................................................................ 11
2.4. Use and care ................................................................................................................................... 11
2.5. Electronic interface ......................................................................................................................... 12
2.6. Keypad and display ......................................................................................................................... 12
2.7. Rear connectors .............................................................................................................................. 13
3. Batteries and Power .................................................................................................................................. 15
3.1. External power................................................................................................................................ 15
3.2. Battery safety .................................................................................................................................. 16
3.3. Battery performance ...................................................................................................................... 16
3.4. Charging the battery ....................................................................................................................... 17
3.5. Storing the battery.......................................................................................................................... 17
3.6. Removing the battery ..................................................................................................................... 17
4. Setting Up the Receiver ............................................................................................................................. 19
4.1. Guidelines ....................................................................................................................................... 19
4.1.1. Environmental conditions .................................................................................................... 19
4.1.2. Sources of electrical interference ........................................................................................ 19
4.1.3. Uninterruptable power supply............................................................................................. 19
4.1.4. Lighting and surge protection .............................................................................................. 20
4.1.5. Placing the antenna ............................................................................................................. 20
4.2. System installation .......................................................................................................................... 21
4.2.1. Supported antenna .............................................................................................................. 21
4.2.2. System installation diagram ................................................................................................. 21
5. Configuring the Receiver: Keypad and Display .......................................................................................... 23
5.1. Button functions ............................................................................................................................. 23
5.2. Home screen ................................................................................................................................... 23
5.3. Status screens ................................................................................................................................. 24
N72 GNSS Reference Receiver User Guide
 Page 5
5.4. Setting up the receiver as part of an Ethernet configuration ......................................................... 25
6. Configuring the Receiver: Other Than Keypad and Display ....................................................................... 26
6.1. Configuring the Ethernet settings ................................................................................................... 26
6.2. Configuring through a web browser ............................................................................................... 27
6.2.1. Changing the settings .......................................................................................................... 28
6.2.1.1. Status menu .............................................................................................................. 28
6.2.1.2. Satellites menu ......................................................................................................... 31
6.2.1.3. Receiver Settings menu ............................................................................................ 33
6.2.1.4. Data Recording menu ............................................................................................... 36
6.2.1.5. IO Settings menu....................................................................................................... 40
6.2.1.6. GPRS menu ............................................................................................................... 44
6.2.1.7. Radio menu ............................................................................................................... 44
6.2.1.8. WAN menu................................................................................................................ 45
6.2.1.9. Wifi menu ................................................................................................................. 47
6.2.1.10. Bluetooth Set menu ................................................................................................ 48
6.2.1.11. Network Service menu ........................................................................................... 48
6.2.1.12. Firmware menu .................................................................................................... 497
7. Default Setting and Configuration Files ..................................................................................................... 50
7.1. Default receiver settings ................................................................................................................. 50
7.1.1. Resetting the receiver to factory defaults............................................................................ 50
7.1.2. Using configuration files to duplicate receiver settings ....................................................... 53
8. Specifications ............................................................................................................................................. 54
8.1. GNSS characteristics ....................................................................................................................... 54
8.2. Communication .............................................................................................................................. 54
8.3. Physical ........................................................................................................................................... 55
8.4. Electrical ......................................................................................................................................... 55
8.5. General ........................................................................................................................................... 55
8.6. Data storage.................................................................................................................................... 56
A. Upgrading the Receiver Firmware ............................................................................................................. 57
A.I. The WinFlash utility......................................................................................................................... 57
A.I.i. Installing the WinFlash utility ................................................................................................ 57
A.II. Upgrading the receiver firmware ................................................................................................... 57
A.II.i. Upgrading through USB port ................................................................................................ 57
A.II.ii. Upgrading through a browser .............................................................................................. 58
B. Troubleshooting ......................................................................................................................................... 59
B.I. Receiver issues................................................................................................................................. 59
C. Communication Ports Definition ............................................................................................................... 61
C.I. CHC N72 Receiver COM 1 (10‐PIN LEMO Port) Definition ............................................................... 61
C.II. CHC N72 Receiver COM 2 (10‐PIN LEMO Port) Definition .............................................................. 61
C.III. CHC N72 Receiver DB9 Male Connector Definition ....................................................................... 62
D. Glossary ..................................................................................................................................................... 63
N72 GNSS Reference Receiver User Guide
 Page 6
1. INTRODUCTION
The N72 GNSS Reference Receiver User Guide describes how to set up and
use the CHC® N72™ GNSS reference receiver.
In this manual, “the receiver” refers to the N72 GNSS reference receiver
unless otherwise stated.
Even if you have used other Global Navigation Satellite Systems (GNSS)
products before, CHC recommends that you spend some time reading this
manual to learn about the special features of this product. If you are not
familiar with GNSS, go to www.chcnav.com for an interactive look at CHC
and GNSS.
1.1. ABOUT THE RECEIVER
The N72 GNSS reference receiver (“the receiver”) is a multiple‐frequency
GNSS receiver. It can track all GPS (L1/L2/L5), GLONASS (L1/L2) and BDS
(B1/B2) signals.
You can use the front panel of the receiver or an office computer to
configure the receiver, access files, and publish data files to a company
Intranet or to the Internet. The receiver makes it easy for you to set up a
powerful, flexible, and reliable reference station for continuous operation.
The receiver serves in all common geodetic reference receiver roles. It can
be the main component in a Continuously Operating Reference Station
(CORS), streaming data to CHC GNSS Infrastructure software. It can also work
well as a campaign receiver prior to permanent deployment. The receiver
makes an excellent portable RTK base station with its internal battery. It also
has specialized capabilities that make it an excellent reference receiver for
scientific applications.
1.2. TECHNICAL SUPPORT
If you have a problem and cannot find the information you need in the
product documentation or CHC website (www.chcnav.com), contact your
local CHC dealer from which you purchased the receiver(s).
If you need to contact CHC technical support, please contact us by email
(support@chcnav.com) or Skype (chc_support).
N72 GNSS Reference Receiver User Guide
 Page 7
1. Introduction
1.3. DISCLAIMER
Before using the receiver, please make sure that you have read and
understood this User Guide, as well as the safety requirements. CHC holds
no responsibility for the wrong operation by users and for the losses
incurred by the wrong understanding about this User Guide. However, CHC
reserves the rights to update and optimize the contents in this guide
regularly. Please contact your local CHC dealer for new information.
1.4. YOUR COMMENTS
Your feedback about this user guide will help us to improve it in future
revision. Please email your comments to support@chcnav.com.
N72 GNSS Reference Receiver User Guide
 Page 8
2. OVERVIEW
This chapter introduces the N72 GNSS reference receiver (“the receiver”).
This receiver makes it easy to set up a powerful and reliable Continuously
Operating Reference Station (CORS) or to collect data from temporary field
locations.
The receiver is ideal for the following infrastructure applications:

As part of a GNSS Infrastructure network in conjunction with CHC
Reference Station Network (CRNet) software.

As part of a permanent reference station with or without supporting
software.

A temporary field base station to broadcast RTK corrections and collect
observations for post processing.
2.1. RECEIVER FRAMEWORK
The receiver integrates the multi‐frequency GNSS technology into a
specialized processing and communications framework. The receiver can
operate as a standalone reference station or it can be integrated into a
scalable network.
With an Internet Protocol (IP) as the primary communications method, you
can use public domain tools, such as a web browser and FTP client, to
configure the receiver and access logged data files.
NOTE ‐ All references to the Internet refer to either a Wide Area
Network (WAN) or a Local Area Network (LAN) connection.
The receiver adopts a secured system that requires a password protected
login for configuration changes and/or file access.
Use the network management features to create a base/rover configuration
with a variety of operating modes. You can then enable those modes as
necessary instead of switching the global state of the receiver from one
mode to another. For example, you can configure a number of streaming
services with different configurations (such as any combination of data
stream, sample interval) on different TCP or UDP ports. To activate one or
more modes, open the connection to the specific port. This allows multiple
clients to access any given streaming service.
These features and many more, shift the model of a GNSS receiver toward
the concept of a "network appliance".
N72 GNSS Reference Receiver User Guide
 Page 9
2. Overview
2.1.1. THE NETWORK APPLIANCE CONCEPT
Traditionally, a GNSS receiver has one operator. That person is the only user
of the receiver so they can change settings without affecting other users.
With the N72 GNSS reference receiver, an operator can configure a receiver
once, and then make it available as a network appliance for general use by
one or more users (or clients).
This network appliance concept lets you set up the receiver to provide one
or more services that one or more users can access through a Local Area
Network (LAN) or a Wide Area Network (WAN), such as the Internet. Once
the receiver is set up, you need make only minimal changes, if any, to the
receiver configuration.
When the receiver is operating as a network appliance, it provides services
to all users attached to the receiver through the network.
Different streamed services may be configured on different ports, for
example, with differing data rates or data combination. To obtain a service,
the client has only to connect to a specific port. In this way, most users do
not need to control the receiver. Changing global settings, such as masks, will
affect all users of all services.
The receiver provides the following standard configuration and data logging
services:
Use...
To perform...
HTTP
All manual and automated configuration operations to manage
the logged data file space.
Remote manual and/or automated operations to manage the
logged data file upload path.
FTP
2.2. RECEIVER SERVICES
The receiver can provide one or more streaming or query services over a
RS‐232 serial port or a TCP/IP port:

Streaming service
Anyone with authorized access can obtain streamed information, such
as GNSS measurements or RTCM corrections, without having to control
or issue commands to the receiver. The client simply connects to the
port that is streaming the required information.
N72 GNSS Reference Receiver User Guide
 Page 10
2. Overview
2.3. RECEIVER FEATURES

220‐channels
– GPS: L1C/A, L2C, L2E, L5
– GLONASS: L1 C/A, L1, L2 C/A, L2P
– Galileo: E1, E5A, E5B
– SBAS: WAAS, EGNOS, MSAS
– BDS: B1, B2

16 GB internal data logging storage

External USB drive support

Integrated battery, provides up to 17 hours operation

Integrated display and keypad for system configuration without a
controller

Integrated Bluetooth wireless technology for cable‐free data
transmission

Permanent/semi‐permanent and mobile quick setup base station
capability

Easy‐to‐use Web‐interface menu system for rapid configuration and
status checking

Rugged, weatherproof construction with an IP67 environmental rating

‐40°C to +65°C (‐40°F to +149°F) operating temperature range

12 V to 36 V DC input power range

Data file generated in HCN

IMX287 processor based on embedded Linux, main frequency up to
450MHz

Eight independent data logging sessions with configurable memory
pooling

Circulating data logging method

FTP push to allow uploading of logged data files to remote sites

Ethernet configuration through the front panel

Multiple languages available through the Web interface

NTRIP (Networked Transport of RTCM via Internet Protocol)
client/server/caster support
2.4. USE AND CARE
This receiver can withstand the rough treatment and tough environment
that typically occurs in CORS installation. However, it is a high‐precision
electronic instrument and should be treated with reasonable care.
CAUTION – Operating or storing the receiver outside the specified
temperature range can damage it. For more information, see Chapter 8
Specifications.
N72 GNSS Reference Receiver User Guide
 Page 11
2. Overview
2.5. ELECTRONIC INTERFACE
High‐power signals from a nearby radio or radar transmitter can overwhelm
the receiver circuits. This does not harm the instrument, but it can prevent
the receiver electronics from functioning correctly.
Avoid locating the receiver or antenna within 400 meters of powerful radar,
television, or other transmitters or GNSS antennas. Low‐power transmitters,
such as those in cell phones and two‐way radios, normally do not interfere
with receiver operations.
2.6. KEYPAD AND DISPLAY
Feature
Description
Power LED
Shows if the power is on or off.
Buttons
Use to turn on, turn off or configure the receiver. See
5.1. Button functions.
Display
This Vacuum Fluorescent display enables you view the
current configuration settings of receiver and the
operation by operators. See 5.3. Home screen.
N72 GNSS Reference Receiver User Guide
 Page 12
2. Overview
2.7. REAR CONNECTORS
2.8.
Connector type
Description
TNC
Connect to the GNSS antenna
SIM card slot
SIM card is inserted here to connect GPRS network
USB

Connect to external USB drive for external data
logging after configured through web interface.

Upgrade the receiver firmware with the
inserted USB driver containing the related
upgrade file after restart the receiver.

Connect the receiver to a computer to
download files from the receiver (as external
storage equipment) to the computer.
TNC
For external GPRS antenna
TNC
For external radio
DB9
RS‐232 serial port, 9‐pin male connector, for data
communication when necessary
RJ45 jack

Supports links to 10BaseT/100BaseT
auto‐negotiate networks

HTTP, TCP/IP, UDP, FTP, NTRIP Caster, NTRIP
Server, NTRIP Client
Lemo (10‐pin) Port 1

Simultaneously transmits multiple data stream

Power from an external AC/DC power supply.

RS‐232 serial communications using a 10‐pin
Lemo cable (CHC Data Cable).

Pass‐through to the mainboard without issuing
the pass‐through command via this port.
Lemo (10‐pin) Port 2

Power from an external AC/DC power supply.

RS‐232 serial communications using a 10‐pin
N72 GNSS Reference Receiver User Guide
 Page 13
2. Overview
Lemo cable (CHC Data Cable).

Data streaming transmission port.
N72 GNSS Reference Receiver User Guide
 Page 14
3. BATTERIES AND POWER
The N72 GNSS reference receiver uses an internal rechargeable Lithium‐ion
battery, which can be replaced only at an Authorized CHC Service Center.
The receiver can also be powered by an external power source that is
connected to either of the Lemo ports.
The operational time provided by the internal battery depends on the type
of measurement and operating conditions. Typically, the internal battery
provides up to 17 hours operation.
NOTE–All battery operational tests are carried out with new,
fully‐charged batteries at room temperature, tracking both GPS and
GLONASS satellites while storing and streaming data at 1 Hz. Older
batteries, at temperatures significantly higher or lower than room
temperature, will have a reduced performance. Power consumption
increases with an increasing number of actively tracked satellites and
with increasing observation and storage rates.
3.1. EXTERNAL POWER
The receiver uses an external power source in preference to its internal
battery. If the receiver is not connected to an external power source, or if
the external power supply fails, the internal battery is used.
The receiver’s internal battery charges only when the external voltage is
above 11 V DC. CHC recommends that the applied external power offers
between 12 V DC and 36 V DC and is able to supply at least 4 W of power for
the long‐term installations and ensuring that the internal battery is charged
and ready to compensate for power supply disruptions.
While carrying out static measurements for post‐processed computations
using the internal memory, if no external power is supplied and the internal
battery is drained, the receiver shuts down. No data is lost; however, when
power is restored, the receiver should be configured again.
WARNING – The external AC power adapter and its associated power cord
and plug are not intended to be installed outdoors, nor in a wet location. Do
not power the receiver through external power when operating in a wet
environment or an environment that may become wet. The power input
connections must be sheltered.
WARNING – When you apply DC voltage to this product through the Lemo
connector, the DC voltage must be limited to 36V DC +0% under both
N72 GNSS Reference Receiver User Guide
 Page 15
3. Batteries and Power
normal and single fault conditions. This product may present an electrical
hazard if the recommended input voltage is exceeded.
3.2. BATTERY SAFETY
The receiver is powered by a rechargeable internal Lithium‐ion battery.
Charge and use the battery only in strict accordance with the following
instructions.
WARNING – Do not damage the rechargeable Lithium‐ion battery. A
damaged battery can cause an explosion or fire, and can result in personal
injury and/or property damage.
To prevent injury or damage:
– Do not use or charge the battery if it appears to be damaged. Signs of
damage include, but are not limited to, discoloration, warping, and
leaking battery fluid.
– Do not expose the battery to fire, high temperature, or direct sunlight.
– Do not immerse the battery in water.
– Do not use or store the battery inside a vehicle during hot weather.
– Do not drop or puncture the battery.
– Do not open the battery or short‐circuit its contacts.
WARNING – Avoid contact with the rechargeable Lithium‐ion battery if it
appears to be leaking. Battery fluid is corrosive, and contact with it can
result in personal injury and/or property damage.
To prevent injury or damage:
– If the battery leaks, avoid contact with the battery fluid.
– If battery fluid gets into your eyes, immediately rinse your eyes with
clean water and seek medical attention. Do not rub your eyes!
– If battery fluid gets onto your skin or clothing, immediately use clean
water to wash off the battery fluid.
3.3. BATTERY PERFORMANCE
To optimize battery performance and extend battery life:

Fully charge all new batteries before use.

Do not use at extreme temperatures. The receiver is designed to
operate at ‐40 °C to +65 °C (‐40 °F to +149 °F). However, operation at
temperatures of less than 0 °C (32 °F) can cause a rapid drop in battery
life.
N72 GNSS Reference Receiver User Guide
 Page 16
3. Batteries and Power
3.4. CHARGING THE BATTERY
The rechargeable Lithium‐ion battery is supplied partially charged. Charge
the battery completely before using it for the first time. If the battery has
been stored for longer than three months, charge it before use.
When connected to a suitable power source, the internal battery charges
fully in 10 hours.
WARNING – Charge and use the rechargeable Lithium‐ion battery only in
strict accordance with the instructions. Charging or using the battery in
unauthorized equipment can cause an explosion or fire, and can result in
personal injury and/or equipment damage.
To prevent injury or damage:
– Do not charge or use the battery if it appears to be damaged or leaking.
– Charge the Lithium‐ion battery only within the N72 receiver. The
battery can only be removed by an authorized CHC Service Center.
3.5. STORING THE BATTERY
The internal Lithium‐ion battery adopts a self‐protection mechanism that
protects the battery from discharge when its voltage is below 6 V and shuts
down the receiver. The internal battery will be activated when charged by
the external power supply.
Do not store the receiver at temperatures outside the range ‐45 °C to +80 °C
(‐49 °F to +176 °F).
The internal battery will only charge from an external power source that
delivers more than 11 V, for example, an AC power adaptor. The receiver is
supplied with a mains power supply unit that recharges the battery inside
the receiver when it is connected through the adaptor to either of the Lemo
ports. When you use the receiver in a long‐term installation, CHC
recommends that you use this power supply or another that provides at
least 12 V DC at all times to keep the internal battery charged. This will
ensure that the internal battery provides an uninterrupted power supply
that will keep the receiver operational for up to 17 hours after a power
failure.
3.6. REMOVING THE BATTERY
The internal Lithium‐ion battery may be removed only at an authorized CHC
N72 GNSS Reference Receiver User Guide
 Page 17
3. Batteries and Power
Service Center. If the battery is removed at an unauthorized service center,
the remaining warranty on the product will be void.
N72 GNSS Reference Receiver User Guide
 Page 18
4. SETTING UP THE RECEIVER
This chapter describes best practices for setting up the equipment, and
outlines the precautions that you must take to protect the equipment. It also
describes the typical installation diagram of reference station composed of
N72 GNSS receiver, GNSS antenna, external power and network cable.
The antenna installation guidelines described here are the minimum
standards. When installing a geodetic antenna to gather precise observation
data, always follow recommended CORS installation practices to the greatest
extent possible.
4.1. GUIDELINES
When you set up the receiver, follow these guidelines.
4.1.1. ENVIRONMENTAL CONDITIONS
The receiver has a waterproof housing but you must take reasonable care to
keep the unit dry.
To improve the performance and long‐term reliability of the receiver, do not
expose the receiver to extreme environmental conditions, such as:

Water

Heat greater than 65 °C (149 °F)

Cold less than ‐40 °C (‐40 °F)

Corrosive fluids and gases
4.1.2. SOURCES OF ELECTRICAL INTERFERENCE
Do not place the GNSS antenna near the following sources of electrical and
magnetic noise:

Gasoline engines (spark plugs)

Televisions and computer monitors

Alternators and generators

Electric motors

Equipment with DC‐to‐AC converters

Fluorescent lights

Switching power supplies

Arc welding equipment
4.1.3. UNINTERRUPTABLE POWER SUPPLY
CHC recommends that you use an uninterruptible power supply (UPS) to
N72 GNSS Reference Receiver User Guide
 Page 19
4. Setting Up the Receiver
power the receiver. The internal battery can also operate as a UPS for up to
17 hours. A UPS protects the equipment from power surges and spikes, and
keeps the receiver running during short power outages.
For more information, contact your local CHC dealer.
4.1.4. LIGHTING AND SURGE PROTECTION
CHC recommends that you install lightning protection equipment at
permanent sites. All connections to the receiver should have surge
protection. Typically, the minimum protection should include a surge
protector in the antenna feed line, on the receiver's power supply system. If
serial devices are attached to the receiver, those serial connections should
also be provided with surge protection. Also, protect any communications
and power lines at building entry points. If you use other antennas, such as a
radio modem that distributes real‐time correction messages, install surge
protection on those antenna feeds as well.
No surge protection devices can offer protection unless they are connected
to an excellent ground using very low impedance conductors. Equipment
damage caused by electrical surges occurs in many permanent installations
even though surge protection is in place. Commonly, this is because the
grounding system used was designed to protect against AC electrical hazards
rather than to dissipate the sudden, high current surges caused by lightning.
Please consult with a lightning protection expert or research the topic when
planning permanent installations.
For more information, contact your local CHC dealer.
4.1.5. PLACING THE ANTENNA
The antenna location will have a significant effect on the quality of your N72
receiver's performance. In temporary developments it may not always be
possible to set up on an ideal location with an excellent sky view. However,
when installing a permanent station, be sure to plan the antenna location
and mounting system carefully.
The general requirements for the antenna location and mount are:

Keep the distance from the objects that may cause the multipath effects
(such as buildings, trees, reflective surface) for at least 200 m (656 feet)

Clear sky above 10 degrees elevation

Away from electromagnetism interference region (e.g. Microwave
station, radio transmitting station, high voltage wires) at least 200 m
(656 feet)

Mounted 1.5 m (5 feet) above any nearby signal reflectors.
N72 GNSS Reference Receiver User Guide
 Page 20
4. Setting Up the Receiver

Mount stability that is not influenced by thermal expansion, wind
loading, or soil expansion/contraction.
For additional information on this topic, research the reference antenna
installation guidelines published by the:

US National Geodetic Survey
(http://www.ngs.noaa.gov/PUBS_LIB/CORS_guidelines.pdf)

International GNSS Service
(http://igscb.jpl.nasa.gov/network/guidelines/guidelines.html)
4.2. SYSTEM INSTALLATION
4.2.1. SUPPORTED ANTENNA
The receiver provides a TNC‐type female connector for connecting to an
antenna. The receiver is intended for use with a CHC Geodetic GNSS antenna
or a CHC GNSS Choke Ring antenna.
CHC A220GR GNSS
CHC C220GR GNSS
Geodetic Antenna
Choke Ring Antenna
Other GNSS antennas may however be used ensuring that the antenna
receive the proper GNSS frequencies and operates at either 3.3V or 7.1V
with a signal greater than 40 dB at the antenna port.
4.2.2. SYSTEM INSTALLATION DIAGRAM
The typical installation diagram of the CHC N72 GNSS receiver connected
with CHC A220GR GNSS Geodetic Antenna, external power supply and
network cable.
N72 GNSS Reference Receiver User Guide
 Page 21
4. Setting Up the Receiver
Network Cable
CHC A220GR GNSS
Geodetic Antenna
GNSS Antenna Cable
CHC Data Cable
Adapter
1.
Install the GNSS antenna at the appropriate location (see 4.1.5. Place
the antenna for the guidelines); connect the antenna to the TNC Plug
Socket of N72 via the GNSS Antenna Cable.
2.
Power the N72 by external power source (e.g. mains supply) with
Adapter via CHC Data Cable.
A. Connect the 10‐pin Lemo of CHC Data Cable to COM 1 or COM 2 of
N72.
B. Plug the male jack connector of Adapter into the female connector
of CHC Data Cable.
C.
Connect two leg plugs or three leg plugs of Adapter to the mains
supply.
3.
Connect the network cable to the RJ45 jack of N72 to link the N72 with
network.
NOTE: Also, the N72 can be powered by external battery via CHC Data
Cable. And the power supply voltage should be controlled between
12 to 36 V DC.
N72 GNSS Reference Receiver User Guide
 Page 22
5. CONFIGURING THE RECEIVER: KEYPAD AND
DISPLAY
The N72 GNSS reference receiver features a front panel user interface with a
keypad and a two‐line alphanumeric display (see page 14). This interface
enables you to configure many of the receiver’s features without using an
external controller or computer.
5.1. BUTTON FUNCTIONS
Use the buttons on the front panel to turn on or turn off the receiver and to
check or change the receiver settings.
Button
Name
Function
Power
Turn on or turn off the receiver.
When the receiver is only powered by internal battery:

To turn on the receiver, press and hold for 3 seconds.

To turn off the receiver, press and hold for 2 seconds.
When the receiver is powered by external power supply:

The receiver will be on with power.

The receiver will be turned off by removing the power supply from
the CHC cable.
Escape
Return to the previous screen or cancel changes you make on a screen.
OK
Advance to the next screen or accept changes you make on a screen.
Up
Move the cursor between multiple fields on a screen, or make changes.
Down
Move the cursor between multiple fields on a screen, or make changes.
Left
Move the cursor between characters in an editable field.
Right
Move the cursor between characters in an editable field.
5.2. HOME SCREEN
This is the main receiver screen.
N72 GNSS Reference Receiver User Guide
 Page 23
5. Configuring the Receiver: Keypad and Display
The Home screen shows:

The name of the product.

The position solution.

The number of satellites being tracked.
As a power‐saving feature, the front panel goes dark after a short period of
inactivity. If the display is not lit and the receiver is on, press ANY BUTTON
to reactivate the display.
5.3. STATUS SCREENS
To review the receiver's current settings in the status screens, press
or
on the front panel. The status screens show the following
information:

Current Network connection state
•
Current IP address (editable)
•
Current IP mask (editable)
•
Current Gateway (editable)
•
Current DNS Server (editable)
•
Current HTTP port (editable)
•
The internal battery power remaining
•
Internal storage memory remaining
•
Receiver hardware version and software version

Receiver serial number and part number
N72 GNSS Reference Receiver User Guide
 Page 24
5. Configuring the Receiver: Keypad and Display
5.4. SETTING UP THE RECEIVER AS PART OF AN ETHERNET
CONFIGURATION
Use the keypad to set up the receiver as part of an Ethernet configuration.
Press
or
press
to enter the edit mode.
1.
to move between different status screens, and then
or connect the receiver with external
Turn on receiver by press
power supply.
2.
Press
or
3.
Press
to edit IP address.
4.
Press
or
or
5.
to move to IP Addr status screen.
to select the character to edit and then press
to change it.
When finished, press
, and then the “Setting Success” message will
appear on the display.
6.
Follow the step 2 to step 5 to edit IP mask, gateway, DNS server and
HTTP port in the IP MASK, Gateway, DNS Server and HTTP PORT status
screen, respectively.
N72 GNSS Reference Receiver User Guide
 Page 25
6. CONFIGURING THE RECEIVER: OTHER THAN
KEYPAD AND DISPLAY
You can configure the N72 GNSS reference receiver to perform a wide variety
of functions. This chapter describes the configuration methods other than
the front panel display, and explains when and why each method is used.
The WinFlash utility described in this chapter is used primarily to update the
receiver firmware.
6.1. CONFIGURING THE ETHERNET SETTINGS
The receiver Ethernet port connects to an Ethernet network, through which
you can access, configure, and monitor the receiver. No serial cable
connection to the receiver is necessary.
The receiver has the following Ethernet settings:
•
IP address
•
IP mask
•
Gateway
•
DNS server
•
HTTP port
The default setting for the HTTP port is 80: This port is not assigned by the
network. HTTP port 80 is the standard port for web servers and enables you
to connect to the receiver by entering only the receiver’s IP address in a web
browser.
For example, using port 80: http://192.168.9.69
If the receiver is set to use a port other than 80, you must enter the IP
address followed by the port number in a web browser.
For example, port 9971: http://169.168.9.69:9971
Users can configure the Ethernet settings through the front panel (see 5.4.
Setting up the receiver as part of an Ethernet configuration) and a web
server. To use a web server, the receiver must be connected to a network
and have a valid Ethernet configuration.
NOTE: The receiver should be configured the Ethernet settings
through the front panel for its first connection to the Internet.
N72 GNSS Reference Receiver User Guide
 Page 26
6. Configuring the Receiver: Other Than Keypad and Display
6.2. CONFIGURING THROUGH A WEB BROWSER
Supported browsers:

Google Chrome


Microsoft Internet Explorer○
version 10, or higher
Apple Safari
To connect to the receiver through a web browser:
1.
Enter the IP address of the receiver into the address bar of the web
browser:
2.
The web browser prompts you to enter a username and password:
The default login account for the receiver is:

Login Account: admin

Password: password
NOTE: Tick remember me option, and then the browser will
remember the Login Account and Password you entered for the next
time you enter this login screen.
3.
Once you are logged in, the web page appears as follows:
N72 GNSS Reference Receiver User Guide
 Page 27
6. Configuring the Receiver: Other Than Keypad and Display
6.2.1. CHANGING THE SETTINGS
The web interface shows the configuration menus on the left of the browser
window, and the setting on the right. Each configuration menu contains the
related submenus to configure the receiver and monitor receiver
performance.
This section describes each configuration menu.
To view the web interface in another language, select the corresponding
language name from the drop‐down list in the upper right corner of the
interface.
Currently, three languages are available:
6.2.1.1. Status menu
This menu provides a quick link to review the receiver's position information,
satellites tracked, runtime, current data log status, current outputs, available
memory, and more.
N72 GNSS Reference Receiver User Guide
 Page 28
6. Configuring the Receiver: Other Than Keypad and Display

Position
This page shows the relevant position information about the receiver's
position solution which including the position, DOP values, satellites
used and tracked, and the receiver clock information.

Operation
Lists several important items to help you understand how the receiver is
being used and its current operating condition. Items include the
identities of currently tracked satellites, internal and external storage
usage rate, how long the receiver has been operational, state of the
internal battery, power source state, files being logged, and data
streams being output. With this information, it is easy to tell exactly
what functions the receiver is performing:
N72 GNSS Reference Receiver User Guide
 Page 29
6. Configuring the Receiver: Other Than Keypad and Display

Google map
Tap this submenu to show the location of the receiver on Google map.
N72 GNSS Reference Receiver User Guide
 Page 30
6. Configuring the Receiver: Other Than Keypad and Display
6.2.1.2. Satellites menu
Use the Satellites menu to view satellite tracking details and enable/disable
GPS, SBAS, GLONASS, BDS and Galileo constellations. These menus include
tabular and graphical displays to provide all required information on satellite
tracking status.

Satellite Track Table
Provides the status of satellites tracked in general, such as the satellite
ID, satellite type, attitude angle, azimuth angle, L1 SNR, L2 SNR, L5 SNR
and enable/disable status of each one.

Satellite Track Diagram
The following figure is an example of satellite track diagram page. Users
can determine the satellite types and the corresponding SNR of L‐band
carriers to be displayed in any combination.
N72 GNSS Reference Receiver User Guide
 Page 31
6. Configuring the Receiver: Other Than Keypad and Display

SkyPlot
The following figure is an example of Skyplot page.

Satellite Settings
In this submenu, users can enable/disable GPS, SBAS, GLONASS, BDS
and Galileo constellations.
N72 GNSS Reference Receiver User Guide
 Page 32
6. Configuring the Receiver: Other Than Keypad and Display
6.2.1.3. Receiver Settings menu
Use this menu to configure settings such as the antenna type and height,
elevation mask and PDOP setting, the reference station coordinates, receiver
resetting and web interface language:

Introduction
This submenu shows the receiver information and reference station
information, including antenna related information, elevation mask
angle, reference station work mode and position, etc.

Antenna Param Settings
Use this screen to configure all of the items relating to the GNSS
antenna. You must enter the correct values for all antenna‐related fields,
as the choices you make significantly affect the accuracy for logged data
N72 GNSS Reference Receiver User Guide
 Page 33
6. Configuring the Receiver: Other Than Keypad and Display
and broadcast RTK correctors:

Reference Station Settings
Use this screen to configure settings such as the station coordinates. You
must enter accurate information in these fields, as this data significantly
affects the accuracy of logged data files and broadcast RTK correctors.
For Reference Station Mode:
There are three available options: Auto Rover, Auto Base and
Manual Base.

Auto Rover: The receiver will serve as Rover after the restart.

Auto Base: The receiver will serve as Base after the restart, and
then broadcast RTK correctors based on coordinates obtained
through single‐point positioning automatically.

Manual Base: The receiver will serve as Base after the restart,
and then broadcast RTK correctors based on the coordinates
before power off.
N72 GNSS Reference Receiver User Guide
 Page 34
6. Configuring the Receiver: Other Than Keypad and Display
For Reference Latitude and Reference Longitude:
There are mainly three methods to enter the reference coordinates
and shown as follows:
 Acquire Current Position: Click this button to acquire current
position obtained through single‐point positioning
automatically.
 Manual Input: Manually input a known coordinates.
 From CORS: After logging in CORS, the receiver will obtain a
coordinates based on fix solution. (See 6.2.1.5. IO Settings
menu for more details about logging in CORS.)
For Sample for Average:
Users can determine the positioning limit and sampling amount.
The positioning limit falls into two types:

Single Solution Coordinates: Collect the coordinates of receiver
obtained through single‐point positioning.

Fixed Solution Coordinates: Only collect coordinates of
receiver based on fix solution.
After the configuration of positioning limit and sampling amount,
click
to carry out sampling and averaging  the result
will be served as the coordinates of current positon.
Also, users can click

to save the curent settings.
Receiver Reset
Use this screen to completely or partially reset the receiver:

Languages
N72 GNSS Reference Receiver User Guide
 Page 35
6. Configuring the Receiver: Other Than Keypad and Display
Use this screen to select the web interface language:
6.2.1.4. Data Recording menu
Use the Data Logging menu to set up the receiver to log static GNSS data and
to view the logging settings. You can configure settings such as observable
rate, recording rate, continuous logging limit, and whether to auto delete old
files if memory is low. This menu also provides the controls for the FTP push
feature:

Log Settings
Shows the data logging status, internal and external storage usage and
data logging status of each storage thread. Also, users can configure the
data logging settings for each storage thread, including recording name,
saving location, storage limit, store formats, start time, etc.
N72 GNSS Reference Receiver User Guide
 Page 36
6. Configuring the Receiver: Other Than Keypad and Display
To open or close all the storage threads, click the [ON] or [OFF] button
to the right of Log Status field.
NOTE – The [ON] and [OFF] button to the right of Log Status field are
the Master Log Switch. Every storage thread can log data only when
the Master Log Switch is ON. And users can edit the settings of
storage threads only when the Master Log Switch is OFF.
To edit the settings of each storage thread, click the [Modify] button to
the right of the required storage thread, and then the Recording Edit
screen appears:
N72 GNSS Reference Receiver User Guide
 Page 37
6. Configuring the Receiver: Other Than Keypad and Display
In this screen, you can set all data logging parameters, and
determine whether the recording files will be affected by the FTP
Push. The parameters are mainly as follows:
 On or Off: Select “Yes” or “No” to determine whether to log
data when the Master Log Switch is ON.
 Recording Name: The name of this storage thread.
 Sample Interval: Select the observable rate from the dropdown
list.
 Store Location: Determine whether to store at internal storage
or external storage.
 Start Time: Set the start time of data log in UTC. Select “Yes” or
“No” option below to determine whether to start logging from
the set time.
 Duration Time: Set the time interval of recording.
 Storage: Set the storage limit of this thread.
 Recycle Storage: Select “Yes” or “No” to determine whether to
auto delete old files if the storage space is full.
 Storage Format: The default format of recording files is HCN.
 FTP Push: Decide whether to push the stored files to the FTP
server of your choice.
Click
to save the settings and back to the Log Settings
screen. Also, users can click
to abandon the changed
settings and back to Log Settings screen.
NOTE – to delete the record data, you can remove all the eight record
data by the total button clear all accounts. Also you can delete each
record data by clear button under the selected thread.
To delete the recorded files of ANY storage thread, click the [Clear]
button to the right of the required storage thread.
To delete the recorded files of ALL storage threads, click [Clear All
Accounts] button.

FTP Push Settings
Use this screen to configure the receiver to push stored files to the FTP
server of your choice. Only files that are configured to use FTP push are
transmitted. Click [Modify] button to the right of the required FTP
server and the FTP Push Settings screen appears:
N72 GNSS Reference Receiver User Guide
 Page 38
6. Configuring the Receiver: Other Than Keypad and Display

FTP Push Recording
Shows the related information about the recorded filed that be pushed.
And users can click [Clear Ftp Send Log] button in the upper right corner
to clear the status of FTP Push operations.

Data Download
In this submenu, users can download the data files that recorded in the
internal storage through the internal FTP site.
1.
Click this submenu, and then the log on dialogue box will prompt
you to enter a user name and password:
The default logon account for the internal FTP site is:
2.

User name: ftp

Password: ftp
Click the directory named as repo to view and download the files
currently stored on the receiver:
N72 GNSS Reference Receiver User Guide
 Page 39
6. Configuring the Receiver: Other Than Keypad and Display
3.
To find the file need to be downloaded, click the name of storage
thread  the date of file that be recorded  the format of the file
 the name of the target file.
4.
To download a file, left‐click the name of the target file 
download the file according to the prompts.
6.2.1.5. IO Settings menu
Use the IO Settings menu to set up all receiver outputs and inputs. The
receiver can output CMR, RTCM, Raw data, Ephemeris data, GPGGA, GPGSV,
on TCP/IP, UDP, serial port, or Bluetooth ports.

IO Settings
The following figure shows an example of the screen that appears when
you select this submenu.
N72 GNSS Reference Receiver User Guide
 Page 40
6. Configuring the Receiver: Other Than Keypad and Display
In this submenu, users can configure 5 types of input and output
settings.
1.
RTK Client
After configuring the settings of RTK client, users can log on CORS or
APIS. Click the [Connect] button to the right  the IO Settings screen
will appear  choose one of the connection protocols among the NTRIP,
APIS_BASE and APIS_ROVER  configure the related parameters 
to log on CORS or APIS.
click

Connection Protocol: NTRIP

Connection Protocol: APIS_BASE
N72 GNSS Reference Receiver User Guide
 Page 41
6. Configuring the Receiver: Other Than Keypad and Display

2.
Connection Protocol: APIS_ROVER
TCP/UDP Client
Click the [Connect] button to the right of required TCP/UDP Client 
the IO Settings screen will appear  select the connection protocol
from the dropdown list  enter the IP and Port of the target server 
configure messages that you want to output to the target server  click
to save and complete the connection.
N72 GNSS Reference Receiver User Guide
 Page 42
6. Configuring the Receiver: Other Than Keypad and Display
NOTE: If the receiver and server are under the same Local Area
Network (LAN), users can use the IP address in LAN of the server with
any Port. However, if the receiver and server are under the two
different LAN, users should use the public IP address of the server
and configure the port mapping of the server.
3.
TCP/IP Server
Click the [Connect] button to the right of required TCP/IP Server  the
IO Settings screen will appear  select one of the connection protocols
between NTRIP and TCP  configure the other related parameters 
to save the settings and open the server.
click

Connection Protocol: NTRIP

Connection Protocol: TCP
N72 GNSS Reference Receiver User Guide
 Page 43
6. Configuring the Receiver: Other Than Keypad and Display
4.
COM Port
Click the [Settings] button to the right of required COM Port  the
Serial Port Setup screen will appear  select Baud Rate used to
transmit data configure the messages that you want to output
through the serial port  click
to save the settings and
start to transmit.
5.
Bluetooth
Click the [Settings] button to the right of Bluetooth  the Bluetooth Set
screen will appear  configure the messages that you want to transmit
through Bluetooth  click
to save the settings and start
to transmit.
N72 GNSS Reference Receiver User Guide
 Page 44
6. Configuring the Receiver: Other Than Keypad and Display
6.2.1.6. GPRS menu
Network Info: network info shows power status, network mode, connection
protocol, signal strength, SIM status and dialing status.
Network set：mainly to set GPRS model status, auto start, network mode
( generally users select [2G/3G Auto]), parameter settings and so on.
6.2.1.7. Radio setting menu
Radio Info: shows radio type, radio power, OTA baud rate, radio frequency
and so on.
Radio setting: to set radio status, auto start, radio power, frequency and so
on. When using web page setting alone and the radio function is required,
users need to turn on Radio Status and Auto Start. If the radio in IO setting is
N72 GNSS Reference Receiver User Guide
 Page 45
6. Configuring the Receiver: Other Than Keypad and Display
required to be used, the premises are also turning on radio status, setting
appropriate frequency, power and so on.
6.2.1.8. WAN menu
Use this menu to check and configure the Ethernet settings.

Network Info
The following figure shows an example of the screen that appears when
you select this submenu:

Network Set
Use this submenu to configure the related parameters of the Network,
including static IP, subnet mask, etc.
N72 GNSS Reference Receiver User Guide
 Page 46
6. Configuring the Receiver: Other Than Keypad and Display
6.2.1.9. Wifi menu
Use this menu to check and configure the Wifi settings.

Wifi Info
The following figure shows an example of the screen that appears when
you select this submenu:

Wifi Settings
Use this submenu to configure the related parameters of the Wi‐Fi
settings, including Wi‐Fi mode, encrypt type, password, etc.
N72 GNSS Reference Receiver User Guide
 Page 47
6. Configuring the Receiver: Other Than Keypad and Display
6.2.1.10. Bluetooth Set menu
Use this menu to configure Bluetooth settings.

Bluetooth Set
The following figure shows an example of the screen that appears when
you select this submenu:
6.2.1.11. Network Service menu
Use this menu to configure the receiver’s HTTP port, and the username and
password of internal FTP site.

HTTP
N72 GNSS Reference Receiver User Guide
 Page 48
6. Configuring the Receiver: Other Than Keypad and Display

FTP Service
6.2.1.12. Firmware menu
Use this menu to check the current firmware information, download the
system log, update the receiver firmware, download or update the
configuration file and register the receiver.

Firmware Info
Use this submenu to check the current firmware information. The
following figure shows an example of the firmware information.

System Log
Use this submenu to download the system log of the receiver.

Firmware Update
Use this submenu to load new firmware to the receiver across the
network. Click the [Browse] button to locate the upgrade file  click
[Confirm] button to confirm the selected upgrading file and start
N72 GNSS Reference Receiver User Guide
 Page 49
6. Configuring the Receiver: Other Than Keypad and Display
upgrading.
NOTE: It will take about 2 or 3 minutes to complete the firmware
upgrading.

Config File
In this submenu, users can download the configuration file by clicking
button and determine a saving path to download the
configuration file (.cfg file). Also, users can click the [Browse] button to
locate the existing configuration file  click [Confirm] button to confirm
the selected file and start updating.

GNSS Registration
Use this submenu to register the receiver. Paste or enter the registration
code to the Registration Code field  click [Registration] button to
complete the registration.
N72 GNSS Reference Receiver User Guide
 Page 50
6. Configuring the Receiver: Other Than Keypad and Display
N72 GNSS Reference Receiver User Guide
 Page 51
7. DEFAULT SETTING AND CONFIGURATION FILES
Most of the receiver settings are stored in application files. The default
application file, Default.cfg, is stored permanently in the receiver, and
contains the factory default settings for the N72 GNSS reference receiver.
Whenever the receiver is reset to its factory defaults, the current settings
(stored in the current configuration file, copy.cfg) are reset to the values in
the default application file.
The N72 GNSS reference receiver extends the use of configuration files to
allow simplified receiver setting duplication in multiple receivers. This is
sometimes referred to as receiver cloning and is very useful when preparing
a large group of receivers for a field data collection campaign.
7.1. DEFAULT RECEIVER SETTINGS
Function
Factory default values
SV Enable
All SVs enabled
General controls
Lemo port
DB9 port
Elevation mask
0°
PDOP mask
6°
Baud rate
9600
Format
8‐None‐1
Flow control
None
Baud rate
9600
Format
8‐None‐1
Flow control
None
Log status
OFF
Differential data
OFF
Raw data
OFF
Ephemeris data
OFF
NMEA (GPGGA, GPGSV)
OFF
Reference position
Antenna
Latitude
0°0’0.00000000’’
Longitude
0°0’0.00000000’’
Height
0.000
Type
CHCA300GNSS
Measure Method
2.0000 (Meter)
Height
Antenna Phase Center
7.1.1. RESETTING THE RECEIVER TO FACTORY DEFAULTS
Log in the web page of the receiver  tap and unfold the Receiver Reset
menu  tap the Receiver Reset submenu click the
button to the right of Back to Default Setting field.
N72 GNSS Reference Receiver User Guide
 Page 52
7. Default Settings and Application Files
7.1.2. USING CONFIGURATION FILES TO DUPLICATE RECEIVER SETTINGS
The N72 GNSS reference receiver allows the extensive use of application files
in order to retain a unique receiver configuration. With this receiver, you can
create a configuration file that includes most of the receiver's unique
configuration settings. You can then update that configuration file onto one
or more other N72 GNSS reference receivers to quickly configure them to
match the receiver which creates that configuration file.
NOTE: The configuration file includes most of the configuration
settings except IP Address, IP Mask, Gateway and DNS Server.
This is called receiver configuration cloning or cloning. Receiver cloning
greatly reduces the time required to prepare a large group of receivers for
field operations.
Log in the web page of the receiver  tap and unfold the Firmware menu
 tap the Config File submenu  click the [Browse] button to locate the
existing configuration file  click [Confirm] button to confirm the selected
file and start updating.
N72 GNSS Reference Receiver User Guide
 Page 53
8. SPECIFICATIONS
This chapter describes the specifications for the N72 GNSS reference receiver.
Specifications are subject to change without notice.
8.1. GNSS CHARACTERISTICS
Feature
Specification
Tracking

220 channels
– GPS: L1 C/A, L2C, L2E, L5
– GLONASS: L1 C/A, L1P, L2C/A, L2P
– SBAS: WAAS, EGNOS, MSAS
– Galileo: E1, E5A, E5B
– BDS: B1, B2

Pseudo‐range measurement with high‐precision
multi‐correlator

Very low noise carrier phase measurements with <1 mm
precision in a 1 Hz bandwidth
Real Time Kinematic (RTK)
Horizontal: 8 mm + 1 ppm RMS
Vertical: 15 mm + 1 ppm RMS
Post Processing Static
Horizontal: 2.5 mm + 0.5 ppm RMS
Vertical: 5 mm + 0.5 ppm RMS
Initialization time
Typically < 10 s
Initialization reliability
Typically > 99.9%
8.2. COMMUNICATION
Feature
Specification
RJ45 Jack
Ethernet
DB9 male
3‐wire RS232, see C.I. CHC N72 receiver COM 1 (10‐pin LEMO port)
definition for details
COM1 (10‐pin LEMO port)
8‐wire RS232, see C.II. CHC N72 receiver COM 2 (10‐pin LEMO port)
definition for details
COM2 (10‐pin LEMO port)
9‐wire RS232, see C.III. CHC N72 receiver db9 male connector
definition for details
USB port
Type‐A USB receptacle, operates in Host mode
Bluetooth
Fully integrated, fully sealed 2.4 GHz Bluetooth wireless technology
Protocols
Correction formats: CMR, CMR+, SCMR, RTCM2.3, 3.0
Observables: RT17, RT27, RTCM3.X
Position/Status I/O: NMEA‐0183 V2.30 (GPGGA & GPGSV)
N72 GNSS Reference Receiver User Guide
 Page 54
8. Specifications
8.3. PHYSICAL
Feature
Specification
Size
265 x 143 x 68 mm (10.4 x 5.6 x 2.7 in)
Weight
2.1 kg (74 oz)
Operating temperature
‐40 °C to +65 °C (‐40 °F to +149 °F)
Storage temperature
‐45 °C to +80 °C (‐49 °F to +176 °F)
Humidity
100% condensation
Waterproof and dust
Tested to IP67; waterproof for temporary immersion to a depth of 1 m
proof
(3.28 ft) for 30 minutes; dustproof
Shock
Designed to survive a 1 m (3.28 ft) drop onto concrete
8.4. ELECTRICAL
Feature
Specification
Power consumption
4 W nominal, dependent on user settings
Internal

Integrated internal battery 7.4 V, 10000 mA‐hr, Lithium‐ion

Internal battery can operate as a UPS in the event of external
power source outage

Internal battery will charge from the external power source when
the internal battery is not fully charged
External

Power source supply (Internal / External) is hot swap capable in the
event of power source removal or cut‐off

Power input on Lemo ports is 12 V DC to 36 V DC external power
input

Receiver will auto power on when connected to external power
with voltage above 11 V
Operation time on
Up to 17 hours continuous operation, dependent on user setting
internal battery
8.5. GENERAL
Feature
Specification
Front panel display

Vacuum Fluorescent Display (VFD), 16 characters by 2 rows

Power button and indication LED

Escape, OK and 4 arrow keys (up, down, left, right)
Receiver type
GNSS reference receiver
Antenna type

CHC A220GR GNSS Geodetic antenna or CHC C220GR GNSS Choke
Ring antenna preferred.

Other models supported.
N72 GNSS Reference Receiver User Guide
 Page 55
8. Specifications
8.6. DATA STORAGE
Feature
Specification
Internal storage
16 GB
External storage
Supporting USB drive or portable hard drive
Storage method
8‐thread logging, circulating data logging
Data format
HCN, RINEX, original binary data
Data download
FTP push, online download, storage on an external USB devices
N72 GNSS Reference Receiver User Guide
 Page 56
A. UPGRADING THE RECEIVER FIRMWARE
The receiver is supplied with the latest version of the receiver firmware
already installed. If a later version of the firmware becomes available, use
the USB device to upgrade the firmware on your receiver. For the latest
firmware resource, please consult your local CHC dealer.
You can also upgrade the receiver through the web interface. The firmware
file required to upgrade the receiver through the Web interface is located in
the folder where the user saves the file. The file type required is the format
update_n72_e_vXXXXX_bYYYYMMDD.bin where XXXXX represents the
version of firmware and YYYYMMDD represents the firmware encapsulation
date.
A.I. THE WINFLASH UTILITY
The WinFlash utility communicates with CHC products to perform various
functions including:

load or verify GPS software of the mainboard

update or verify the receiver options
For more information, online help is also available when using the WinFlash
utility.
A.I.i. INSTALLING THE WINFLASH UTILITY
You can download the WinFlash utility from the Trimble website. This
self‐extracting executable guides you through the software installation
process.
A.II. UPGRADING THE RECEIVER FIRMWARE
A.II.i. UPGRADING THROUGH USB PORT
1.
Copy the firmware file to the root directory of external storage device
such as USB drive, portable hard drive.
2.
Connect the external storage device with receiver through USB port.
3.
Restart the receiver and then the screen will prompt you whether to
upgrade the firmware.
4.
Press OK button to upgrade the firmware.
5.
When the upgrading is completed, the receiver will be restarted and
the screen will prompt you whether to upgrade the firmware again.
6.
Press one of the arrow keys to quit the upgrading and then remove the
external storage device.
N72 GNSS Reference Receiver User Guide
 Page 57
A. Upgrading the Receiver Firmware
A.II.ii. UPGRADING THROUGH A BROWSER
Please connect to the receiver through a web browser according to 6.2.
Configuring through a web browser, and then refer to 6.2.1.10 Firmware
menu  Firmware Update for detail operation steps.
NOTE: After the receiver firmware upgrading, the IP information may
be changed. Please confirm the IP setting of the receiver before using
it.
N72 GNSS Reference Receiver User Guide
 Page 58
B. TROUBLESHOOTING
Use this appendix to identify and solve common problems that may occur
during the use of the receiver.
Please read this section before you contact CHC Technical Support.
B.I. RECEIVER ISSUES
This section describes some possible receiver issues, possible causes, and
how to solve them.
Issue
Possible cause
Solution
The receiver does
External power is too
Check the charge on the external battery and, if applicable,
not turn on.
low.
check the fuse.
Internal power is too
Check the charge on the internal battery.
low.
External power is not
Check that the Lemo connector is seated correctly and that
properly connected.
the cable is secured to the receiver.
Faulty power cable.
Check that you are using the correct cable for the
Check for broken or bent pins in the connector.
connection between Lemo port and external power supply.
Check that the correct external power supply is connected
to a particular Lemo port.
Check pinouts with a multimeter to ensure internal wiring
is intact.
Receiver does not
The receiver is tracking
Wait until the receiver display shows that more than four
log data.
fewer than four
satellites are being tracked.
satellites.
Turn off the receiver and then turn it back on again.
The receiver is not
Receiver needs a soft
responding.
reset.
The reference
Port settings between
Check the port settings for the receiver by using the Web
station receiver is
reference receiver and
interface. Check that the radio ports are correctly set up.
not broadcasting.
radio are incorrect.
Faulty cable between
receiver and radio.
Try a different cable.
Examine the ports for missing pins.
Use a multimeter to check pinouts.
No power to radio.
The receiver is not
The GNSS antenna cable
If the radio has its own power supply, check the charge and
connections.
Make sure that the GNSS antenna cable is tightly seated in
receiving satellite
is loose.
the antenna connector on the GNSS antenna.
The cable is damaged.
Check the cable for any signs of damage. A damaged cable
signals
can inhibit signal detection from the antenna at the
receiver.
N72 GNSS Reference Receiver User Guide
 Page 59
B. Troubleshooting
The GNSS antenna is not
Make sure that the GNSS antenna is located with a clear
in clear line of sight to
view of the sky.
the sky.
Restart the receiver as a last resort (turn off and then turn
it on again).
N72 GNSS Reference Receiver User Guide
 Page 60
C. COMMUNICATION PORTS DEFINITION
C.I. CHC N72 RECEIVER COM 1 (10‐PIN LEMO PORT)
DEFINITION
PIN
Signal Name
Description
RXD
RS232‐RX (pass‐through to the mainboard through this pin)
TXD
RS232‐TX (pass‐through to the mainboard through this pin)
PWR
External Power Input (positive pole)
PWR
External Power Input (positive pole)
PWR, GND
External Power Input (negative pole), External Power Ground
PWR, GND
External Power Input (negative pole), External Power Ground
Signal
PPS signal output
Not Used
Not Used
10
Signal
EVENT signal input
C.II. CHC N72 RECEIVER COM 2 (10‐PIN LEMO PORT)
DEFINITION
PIN
Signal Name
Description
RXD
RS232‐RX (receive data through this pin)
TXD
RS232‐TX (transmit data through this pin)
PWR
External Power Input (positive pole)
PWR
External Power Input (positive pole)
PWR, GND
External Power Input (negative pole), External Power Ground
N72 GNSS Reference Receiver User Guide
 Page 61
C. Communication Ports Definition
PWR, GND
External Power Input (negative pole), External Power Ground
VBUS
USB device
DM
USB device
DP
USB device
10
Not Used
C.III. CHC N72 RECEIVER DB9 MALE CONNECTOR DEFINITION
PIN
Signal Name
Description
Not Used
TXD
RS232‐TX (transmit data through this pin)
RXD
RS232‐RX (receive data through this pin)
Not Used
GND
Not Used
Not Used
Not Used
Not Used
External Power Ground
N72 GNSS Reference Receiver User Guide
 Page 62
D. GLOSSARY
base station
Also called reference station. A base station in construction, is a receiver placed at
a known point on a jobsite that tracks the same satellites as an RTK rover, and
provides a real‐time differential correction message stream through radio to the
rover, to obtain centimeter level positions on a continuous real‐time basis. A base
station can also be a part of a virtual reference station network, or a location at
which GPS observations are collected over a period of time, for subsequent
postprocessing to obtain the most accurate position for the location.
carrier
A radio wave having at least one characteristic (such as frequency, amplitude, or
phase) that can be varied from a known reference value by modulation.
carrier frequency
The frequency of the unmodulated fundamental output of a radio transmitter. The
GPS L1 carrier frequency is 1575.42 MHz.
carrier phase
The time taken for the L1 or L2 carrier signal generated by the satellite to reach
the GPS receiver. Measuring the number of carrier waves between the satellite
and receiver is a very accurate method of calculating the distance between them.
CMR
Compact Measurement Record. A real‐time message format developed by Trimble
CMR+
for broadcasting corrections to other Trimble mainboard receivers. CMR is a more
efficient alternative to RTCM.
DGPS
See real‐time differential GPS.
differential
Differential correction is the process of correcting GPS data collected on a rover
correction
with data collected simultaneously at a base station. Because the base station is
on a known location, any errors in data collected at the base station can be
measured, and the necessary corrections applied to the rover data.
Differential correction can be done in real‐time, or after the data has been
collected by postprocessing.
Differential GPS
See real‐time differential GPS.
DOP
Dilution of Precision. A measure of the quality of GPS positions, based on the
geometry of the satellites used to compute the positions. When satellites are
widely spaced relative to each other, the DOP value is lower, and position accuracy
is greater. When satellites are close together in the sky, the DOP is higher and GPS
positions may contain a greater level of error.
PDOP (Position DOP) indicates the three‐dimensional geometry of the satellites.
Other DOP values include HDOP (Horizontal DOP) and VDOP (Vertical DOP), which
indicate the accuracy of horizontal measurements (latitude and longitude) and
vertical measurements respectively. PDOP is related to HDOP and VDOP as
follows:
PDOP² = HDOP² + VDOP²
dual‐frequency
A type of receiver that uses both L1 and L2 signals from GPS satellites. A
GPS
dual‐frequency receiver can compute more precise position fixes over longer
distances and under more adverse conditions because it compensates for
ionospheric delays.
EGNOS
European Geostationary Navigation Overlay Service. A satellite‐based
augmentation system (SBAS) that provides a free‐to‐air differential correction
service for GPS.
EGNOS is the European equivalent of WAAS, which is available in the United
N72 GNSS Reference Receiver User Guide
 Page 63
D. Glossary
States.
elevation mask
The angle below which the receiver will not track satellites. Normally set to 10
degrees to avoid interference problems caused by buildings and trees, and
multipath errors.
ephemeris /
A list of predicted (accurate) positions or locations of satellites as a function of
ephemerides
time. A set of numerical parameters that can be used to determine a satellite’s
position.
Available as broadcast ephemeris or as postprocessed precise ephemeris.
epoch
The measurement interval of a GPS receiver. The epoch varies according to the
measurement type: for real‐time measurement it is set at one second; for
postprocessed measurement it can be set to a rate of between one second and
one minute. For example, if data is measured every 15 seconds, loading data using
30‐second epochs means loading every alternate measurement.
firmware
The program inside the receiver that controls receiver operations and hardware.
GLONASS
Global Orbiting Navigation Satellite System. GLONASS is a Soviet space‐based
navigation system comparable to the American GPS system. The operational
system consists of 21 operational and 3 non‐operational satellites in 3 orbit
planes.
GNSS
Global Navigation Satellite System.
GSOF
General Serial Output Format. A Trimble proprietary message format.
HDOP
Horizontal Dilution of Precision. HDOP is a DOP value that indicates the accuracy
of horizontal measurements. Other DOP values include VDOP (vertical DOP) and
PDOP (Position DOP).
Using a maximum HDOP is ideal for situations where vertical precision is not
particularly important, and your position yield would be decreased by the vertical
component of the PDOP ( for example, if you are collecting data under canopy).
L1
The primary L‐band carrier used by GPS satellites to transmit satellite data.
L2
The secondary L‐band carrier used by GPS satellites to transmit satellite data.
L5
The third L‐band carrier used by GPS satellites to transmit satellite data. L5 will
provide a higher power level than the other carriers. As a result, acquiring and
tracking weak signals will be easier.
MSAS
MTSAT Satellite‐Based Augmentation System. A satellite‐based augmentation
system (SBAS) that provides a free‐to‐air differential correction service for GPS.
MSAS is the Japanese equivalent of WAAS, which is available in the United States.
multi‐frequency
A type of receiver that uses multiple carrier phase measurements (L1, L2, and L5)
GPS
from different satellite frequencies.
multipath
Interference, similar to ghosts on a television screen that occurs when GPS signals
arrive at an antenna having traversed different paths. The signal traversing the
longer path yields a larger pseudorange estimate and increases the error. Multiple
paths can arise from reflections off the ground or off structures near the antenna.
NMEA
National Marine Electronics Association. NMEA 0183 defines the standard for
interfacing marine electronic navigational devices. This standard defines a number
of 'strings' referred to as NMEA strings that contain navigational details such as
positions. Most CHC GPS receivers can output positions as NMEA strings.
PDOP
Position Dilution of Precision. PDOP is a DOP value that indicates the accuracy of
N72 GNSS Reference Receiver User Guide
 Page 64
D. Glossary
three‐dimensional measurements. Other DOP values include VDOP (vertical DOP)
and HDOP (Horizontal Dilution of Precision).
Using a maximum PDOP value is ideal for situations where both vertical and
horizontal precision are important.
postprocessing
Postprocessing is the processing of satellite data after it has been collected, in
order to eliminate error. This involves using computer software to compare data
from the rover with data collected at the base station.
real‐time
Also known as real‐time differential correction or DGPS. Real‐time differential GPS
differential
is the process of correcting GPS data as you collect it. Corrections are calculated at
GPS
a base station and then sent to the receiver through a radio link. As the rover
receives the position it applies the corrections to give you a very accurate position
in the field.
Most real‐time differential correction methods apply corrections to code phase
positions. RTK uses carrier phase measurements.
While DGPS is a generic term, its common interpretation is that it entails the use
of single‐frequency code phase data sent from a GPS base station to a rover GPS
receiver to provide sub‐meter position accuracy. The rover receiver can be at a
long range (greater than 100 km (62 miles)) from the base station.
reference station
See base station
rover
A rover is any mobile GPS receiver that is used to collect or update data in the
field, typically at an unknown location.
RTCM
Radio Technical Commission for Maritime Services. A commission established to
define a differential data link for the real‐time differential correction of roving GPS
receivers. There are three versions of RTCM correction messages. All CHC GPS
receivers use Version 2 protocol for single‐frequency DGPS type corrections.
Carrier phase corrections are available on Version 2, or on the newer Version 3
RTCM protocol, which is available on certain CHC dual‐frequency receivers. The
Version 3 RTCM protocol is more compact but is not as widely supported as
Version 2.
RTK
Real‐time kinematic. A real‐time differential GPS method that uses carrier phase
measurements for greater accuracy.
SBAS
Satellite‐Based Augmentation System. SBAS is based on differential GPS, but
applies to wide area (WAAS/EGNOS and MSAS) networks of reference stations.
Corrections and additional information are broadcast via geostationary satellites.
signal‐to‐noise
SNR. The signal strength of a satellite is a measure of the information content of
ratio
the signal, relative to the signal’s noise. The typical SNR of a satellite at 30°
elevation is between 47 and 50 dBHz. The quality of a GPS position is degraded if
the SNR of one or more satellites in the constellation falls below 39.
skyplot
The satellite skyplot confirms reception of a differentially corrected GPS signal and
displays the number of satellites tracked by the GPS receiver, as well as their
relative positions.
SNR
See signal‐to‐noise ratio
UTC
Universal Time Coordinated. A time standard based on local solar mean time at
the Greenwich meridian.
VRS
Virtual Reference Station. A VRS system consists of GNSS hardware, software, and
N72 GNSS Reference Receiver User Guide
 Page 65
D. Glossary
communication links. It uses data from a network of reference stations to provide
corrections to each rover that are more accurate than corrections from a single
base station.
To start using VRS corrections, the rover sends its position to the VRS server. The
VRS server uses the reference station data to model systematic errors (such as
ionospheric noise) at the rover position. It then sends RTCM or CMR correction
messages back to the rover.
WAAS
Wide Area Augmentation System. WAAS was established by the Federal Aviation
Administration (FAA) for flight and approach navigation for civil aviation. WAAS
improves the accuracy and availability of the basic GPS signals over its coverage
area, which includes the continental United States and outlying parts of Canada
and Mexico.
The WAAS system provides correction data for visible satellites. Corrections are
computed from ground station observations and then uploaded to two
geostationary satellites. This data is then broadcast on the L1 frequency, and is
tracked using a channel on the GPS receiver, exactly like a GPS satellite.
Use WAAS when other correction sources are unavailable, to obtain greater
accuracy than autonomous positions. For more information on WAAS, refer to the
FAA website at http://gps.faa.gov.
The EGNOS service is the European equivalent and MSAS is the Japanese
equivalent of WAAS.
N72 GNSS Reference Receiver User Guide
 Page 66
CHC ‐ Shanghai HuaCe Navigation Technology Ltd.
Building C, NO. 599 Gaojing Road,
Qingpu District, 201702 Shanghai, China
Tel: +86 21 542 60 273
Fax: +86 21 649 50 963
Email: sales@chcnav.com | support@chcnav.com
Website: www.chcnav.com

---

Source Exif Data:

File Type                       : PDF
File Type Extension             : pdf
MIME Type                       : application/pdf
PDF Version                     : 1.5
Linearized                      : Yes
Author                          : jiaxing.ye
Create Date                     : 2015:09:02 18:21:19+08:00
Modify Date                     : 2015:09:02 18:21:19+08:00
XMP Toolkit                     : Adobe XMP Core 4.2.1-c043 52.372728, 2009/01/18-15:08:04
Creator Tool                    : PScript5.dll Version 5.2.2
Producer                        : Acrobat Distiller 9.5.5 (Windows)
Format                          : application/pdf
Title                           : Microsoft Word - SY4-A02003__User?Manual Rev2.doc
Creator                         : jiaxing.ye
Document ID                     : uuid:11d2b60a-7824-4e09-9646-1484fda43999
Instance ID                     : uuid:16d4ef39-e948-45b1-a37b-9064d2ce2658
Page Count                      : 68

EXIF Metadata provided by EXIF.tools