Trimble NetRS User Manual

NetRS™ GPS Receiver

User Guide

F

Version 1.11

Revision A

November 2004

Corporate Office

Trimble Navigation Limited
Geomatics and Engineering Division
5475 Kellenburger Road
Dayton, Ohio 45424-1099
USA
800-538-7800 (toll free in USA)
[phone] Phone
[phone] Fax
www.trimble.com

Copyright and Trademarks

© 2003–2004, Trimble Navigation Limited. All rights
reserved.

Trimble, and the Globe & Triangle logo are trademarks
of Trimble Navigation Limited, registered in the United
States Patent and Trademark Office and in other
countries. CMR+, EVEREST, NetRS, TRIMCOMM,
TRIMMARK, TRIMTALK, and Zephyr are trademarks
of Trimble Navigation Limited. Microsoft and Windows
are either registered trademarks or trademarks of
Microsoft Corporation in the United States and/or other
countries. All other trademarks are the property of their
respective owners.

This product is covered by the following patents:
US: 5148179, 5187450, 5202694, 5311149, 5402450,
5493588, 5515057, 5519620, 5602741, 5757646,
6252863, 6175848. US and Foreign patents pending.

Release Notice

This is the November 2004 release (Revision A) of the
NetRS GPS Receiver User Guide. It applies to version 1.11
of the NetRS GPS receiver.

The following limited warranties give you specific legal
rights. You may have others, which vary from
state/jurisdiction to state/jurisdiction.

Product Limited Warranty

Subject to the terms and conditions set forth herein,
Trimble warrants that for a period of (1) year starting
from the date of purchase, this Trimble product,
including any software components, (the "Product") will
substantially conform to Trimble's publicly available
specifications for the Product and that the hardware and
any storage media components of the Product will be
substantially free from defects in materials and
workmanship.

Product Software

Product software, whether built into hardware circuitry
as firmware, provided as a standalone computer software
product, embedded in flash memory, or stored on
magnetic or other media, is licensed and not sold. If
accompanied by a separate end user license agreement,
use of any such software will be subject to the terms of
such end user license agreement (including any differing

limited warranty terms, exclusions and limitations),
which shall control over the terms and conditions set
forth in this limited warranty).

Software Updates

Please refer to the "Firmware" heading of the NetRS
GPS Receiver web site user interface for information
about software updates available for this Product.

Warranty Exclusions and Disclaimer

This Product limited warranty shall only apply in the
event and to the extent that (i) the Product is properly
and correctly installed, configured, interfaced,
maintained, stored, and operated in accordance with
Trimble's relevant operator's manual and specifications,
and; (ii) the Product is not modified or misused. This
Product limited warranty shall not apply to, and Trimble
shall not be responsible for defects or performance
problems resulting from (i) the combination or
utilization of the Product with hardware or software
products, information, data, systems, interfaces or
devices not made, supplied or specified by Trimble; (ii)
the operation of the Product under any specification
other than, or in addition to, Trimble's standard
specifications for its products; (iii) the unauthorized,
installation, modification, or use of the Product; (iv)
damage caused by: accident, lightning or other electrical
discharge, fresh or salt water immersion or spray; or
exposure to environmental conditions for which the
Product is not intended; or (v) normal wear and tear on
consumable parts (e.g., batteries). Trimble does not
warrant or guarantee the results obtained through the use
of the Product. TRIMBLE IS NOT RESPONSIBLE
FOR THE OPERATION OR FAILURE OF
OPERATION OF GPS SATELLITES OR THE
AVAILABILITY OF GPS SATELLITE SIGNALS.

THE FOREGOING LIMITED WARRANTY TERMS
STATE TRIMBLE'S ENTIRE LIABILITY, AND
YOUR EXCLUSIVE REMEDIES, RELATING TO
PERFORMANCE OF THE TRIMBLE PRODUCT.
EXCEPT AS OTHERWISE EXPRESSLY PROVIDED
HEREIN, THE PRODUCT AND ACCOMPANYING
DOCUMENTATION AND MATERIALS ARE
PROVIDED "AS-IS" AND WITHOUT EXPRESS OR
IMPLIED WARRANTY OF ANY KIND, BY EITHER
TRIMBLE OR ANYONE WHO HAS BEEN
INVOLVED IN ITS CREATION, PRODUCTION,
INSTALLATION, OR DISTRIBUTION, INCLUDING,
BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE, TITLE,
AND NONINFRINGEMENT. THE STATED
EXPRESS WARRANTIES ARE IN LIEU OF ALL
OBLIGATIONS OR LIABILITIES ON THE PART OF
TRIMBLE ARISING OUT OF, OR IN CONNECTION
WITH, ANY PRODUCT.

NetRS GPS Receiver User Guide

SOME STATES AND JURISDICTIONS DO NOT
ALLOW LIMITATIONS ON DURATION OR THE
EXCLUSION OF AN IMPLIED WARRANTY, SO
THE ABOVE LIMITATION MAY NOT APPLY TO
YOU.

Limitation of Liability

TRIMBLE'S ENTIRE LIABILITY UNDER ANY
PROVISION HEREIN SHALL BE LIMITED TO THE
AMOUNT PAID BY YOU FOR THE PRODUCT. TO
THE MAXIMUM EXTENT PERMITTED BY
APPLICABLE LAW, IN NO EVENT SHALL
TRIMBLE OR ITS SUPPLIERS BE LIABLE FOR
ANY INDIRECT, SPECIAL, INCIDENTAL OR
CONSEQUENTIAL DAMAGES WHATSOEVER
UNDER ANY CIRCUMSTANCE OR LEGAL
THEORY RELATING IN ANYWAY TO THE
PRODUCTS, SOFTWARE AND ACCOMPANYING
DOCUMENTATION AND MATERIALS,
(INCLUDING, WITHOUT LIMITATION, DAMAGES
FOR LOSS OF BUSINESS PROFITS, BUSINESS
INTERRUPTION, LOSS OF DATA, OR ANY OTHER
PECUNIARY LOSS), REGARDLESS OF WHETHER
TRIMBLE HAS BEEN ADVISED OF THE
POSSIBILITY OF ANY SUCH LOSS AND
REGARDLESS OF THE COURSE OF DEALING
WHICH DEVELOPS OR HAS DEVELOPED
BETWEEN YOU AND TRIMBLE. BECAUSE SOME
STATES AND JURISDICTIONS DO NOT ALLOW
THE EXCLUSION OR LIMITATION OF LIABILITY
FOR CONSEQUENTIAL OR INCIDENTAL
DAMAGES, THE ABOVE LIMITATION MAY NOT
APPLY TO YOU.

Export/Import Restrictions. By your acquisition or use
of this Product you agree to comply with all applicable
export and import laws and restrictions and regulations
of the United States and foreign countries, and shall not
export, re-export, import, transfer, or divert the Product
in whole or in part (i) to any destination restricted or
prohibited by U.S. export control laws or to any national
or resident thereof, (ii) to any denied or restricted
individual or entity under such laws and regulations, or
(iii) without all necessary authorizations required by law.

NOTE: THE ABOVE TRIMBLE LIMITED
WARRANTY PROVISIONS WILL NOT APPLY
TO PRODUCTS PURCHASED IN THOSE
JURISDICTIONS, SUCH AS COUNTRIES OF
THE EUROPEAN ECONOMIC COMMUNITY, IN
WHICH PRODUCT WARRANTIES ARE
OBTAINED FROM THE LOCAL DISTRIBUTOR.
IN SUCH CASE, PLEASE CONTACT YOUR
TRIMBLE DEALER FOR APPLICABLE
WARRANTY INFORMATION.

Notices

Class B Statement – Notice to Users. This equipment
has been tested and found to comply with the limits for a
Class B digital device, pursuant to Part 15 of the FCC
rules. These limits are designed to provide reasonable
protection against harmful interference in a residential
installation. This equipment 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 communication. However,
there is no guarantee that interference will not occur in a
particular installation. If this equipment 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 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

the 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.

Changes and modifications not expressly approved by
the manufacturer or registrant of this equipment can void
your authority to operate this equipment under Federal
Communications Commission rules.

Regulations and Safety

S

TATEMENT ACCORDING FCC PART 15.19

This device complies with Part 15 of the FCC Rules.
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.

TATEMENT ACCORDING FCC PART 15.21

S
Modifications not expressly approved by Trimble could

void the user's authority to operate the equipment.

CE Declaration of Conformity

This product conforms to the following standards, and
therefore complies with the requirements of the R&TTE
Directive 1999/5/EC, which specifies compliance with
the essential requirements of EMC Directive
89/336/EEC and Low Voltage Directive 73/23/EEC:

EMC Emissions:BSEN 55022:1998 (W/A1:00) Class B
EMC Immunity:EN 55024:1998
Safety:EN 60950:2000

Mark First Applied: 03
The technical file is maintained at: Trimble Navigation

Limited, 645 North Mary Avenue, Post Office Box
3642, Sunnyvale, CA 94088-3642, USA

NetRS GPS Receiver User Guide

NetRS GPS Receiver User Guide

Contents

1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 1

About the NetRS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Related Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Technical Assistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Your Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

The Network Appliance Concept . . . . . . . . . . . . . . . . . . . . . . . 5

NetRS Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Use and Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Electronic Interference . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Security Threat (COCOM) Limits . . . . . . . . . . . . . . . . . . . . . . 9

3 Features and Functions . . . . . . . . . . . . . . . . . . . 11

Features of the Receiver. . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Front panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Rear panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Power ports. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Button Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Power button operations . . . . . . . . . . . . . . . . . . . . . . . 18

Power saving mode. . . . . . . . . . . . . . . . . . . . . . . . . . 19

Other power operations . . . . . . . . . . . . . . . . . . . . . . . 20

To erase the almanac and the ephemeris . . . . . . . . . . . . . . . 21

To reset the receiver to factory defaults settings . . . . . . . . . . . 21

LED Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

LED startup sequence . . . . . . . . . . . . . . . . . . . . . . . . 22

NetRS GPS Receiver User Guide v

Contents

LED flash patterns . . . . . . . . . . . . . . . . . . . . . . . . . . 25

4 Setting Up the Receiver . . . . . . . . . . . . . . . . . . . 27

Setup Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Environmental conditions . . . . . . . . . . . . . . . . . . . . . . 28

Sources of electrical interference . . . . . . . . . . . . . . . . . . 28

Uninterruptible power supply . . . . . . . . . . . . . . . . . . . . 29

Lightning protection . . . . . . . . . . . . . . . . . . . . . . . . . 29

Mounting the receiver . . . . . . . . . . . . . . . . . . . . . . . . 30

Placing the antenna. . . . . . . . . . . . . . . . . . . . . . . . . . 30

Connecting the Receiver to Other Devices . . . . . . . . . . . . . . . . . 31

Antenna. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Antenna cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Met-Tilt sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Dial-up modems and terminal adapters . . . . . . . . . . . . . . . 33

Radio modems . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

External frequency reference. . . . . . . . . . . . . . . . . . . . . 34

5 Configuring the Receiver . . . . . . . . . . . . . . . . . . 35

Setting up Communications. . . . . . . . . . . . . . . . . . . . . . . . . 36

Configuring the Ethernet connection. . . . . . . . . . . . . . . . . 37

Configuring the Receiver Through a Web Browser. . . . . . . . . . . . . 41

Web-based menu . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Configuring the Receiver for Connected Devices . . . . . . . . . . . . . 45

Dial-up modem, radio modem, or terminal adapter . . . . . . . . . 45

Configuring Met-Tilt sensors . . . . . . . . . . . . . . . . . . . . 47

Configuring the GPSBase or GPSNet software . . . . . . . . . . . 48

Updating the Receiver Firmware . . . . . . . . . . . . . . . . . . . . . . 49

Downloading the firmware upgrade . . . . . . . . . . . . . . . . . 50

Uploading the firmware . . . . . . . . . . . . . . . . . . . . . . . 50

Installing the firmware upgrade . . . . . . . . . . . . . . . . . . . 50

vi NetRS GPS Receiver User Guide

Contents

6 Logging and Managing Data . . . . . . . . . . . . . . . . 53

Data Logging Sessions . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Creating or editing a session . . . . . . . . . . . . . . . . . . . . . 56

Enabling a session . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Disabling a session . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Naming Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Auto Delete. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Managing Files Through the Web Interface . . . . . . . . . . . . . . . . 58

Storing files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Sorting files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Downloading files . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Deleting files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Managing Files Using FTP . . . . . . . . . . . . . . . . . . . . . . . . . 60

7 Real-Time Data and Services . . . . . . . . . . . . . . . . 63

Streamed Data Services . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

RT17 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Trimcom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

BINEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

CMR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

RTCM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Collecting Data as a Client . . . . . . . . . . . . . . . . . . . . . . . . . 66

8 Other System Information. . . . . . . . . . . . . . . . . . 67

Default Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Cables and Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Cables and connectors . . . . . . . . . . . . . . . . . . . . . . . . 74

Port pinouts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

1PPS Output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

1PPS Pulse Definition . . . . . . . . . . . . . . . . . . . . . . . . 76

NetRS GPS Receiver User Guide vii

Contents

Deployment Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

Configuring from Factory Defaults . . . . . . . . . . . . . . . . . 78

Monitoring Operation . . . . . . . . . . . . . . . . . . . . . . . . 78

Changing Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

Changing the Configuration . . . . . . . . . . . . . . . . . . . . . 79

NetRS Support Software . . . . . . . . . . . . . . . . . . . . . . . . . . 80

Data Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

T00 to DAT file conversion . . . . . . . . . . . . . . . . . . . 80

RT17 to DAT file conversion. . . . . . . . . . . . . . . . . . . 81

DAT to RINEX file conversion . . . . . . . . . . . . . . . . . 81

Setting Up a PPP Connection . . . . . . . . . . . . . . . . . . . . . . . . 83

Linux Operating System . . . . . . . . . . . . . . . . . . . . . . . 83

Windows Operating System . . . . . . . . . . . . . . . . . . . . . 84

Creating a PPP connection . . . . . . . . . . . . . . . . . . . . 85

Configuring a PPP connection . . . . . . . . . . . . . . . . . . 86

Using the PPP connection . . . . . . . . . . . . . . . . . . . . 89

Closing the PPP session . . . . . . . . . . . . . . . . . . . . . 89

Re-connecting the PPP session . . . . . . . . . . . . . . . . . . 90

Editing PPP connection properties . . . . . . . . . . . . . . . . 90

Deleting a PPP connection . . . . . . . . . . . . . . . . . . . . 90

Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

viii NetRS GPS Receiver User Guide

CHAPTER

1

Introduction 1

Welcome to the NetRS GPS Receiver User Guide. This manual
describes how to set up and use the Trimble® NetRS™ GPS receiver.

Even if you have used other Global Positioning System (GPS)
products before, Trimble recommends that you spend some time
reading this manual to learn about the special features of this product.

If you are not familiar with GPS, visit the Trimble website
(www.trimble.com) for an interactive look at Trimble and GPS.

this publication assumes that you are familiar with the Microsoft®
Windows® operating system and know how to use a mouse, select
options from menus and dialogs, make selections from a list, and refer
to online help.

1.1 About the NetRS

The NetRS receiver is a dual-frequency GPS receiver that runs on a
Linux operating system and communicates mainly through local and
wide area networks. You can operate the receiver as a stand-alone
reference station or integrate it into a scalable network.

You will use an office computer to configure the receiver, access files,
or publish data files to a company intranet or to the Internet.

The NetRS receiver makes it easy for you to set up a powerful,
flexible, and reliable reference station for continuous operation.

NetRS Receiver User Guide 1

1 Introduction

1.2 Related Information

Sources of related information include the following:

• Release notes – the release notes describe new features of the
product, information not included in the manuals, and any
changes to the manuals.

• Trimble training courses – consider a training course to help
you use your GPS system to its fullest potential. For more
information, visit the Trimble website at

www.trimble.com/support.html.

1.3 Technical Assistance

If you have a problem and cannot find the information you need in the
product documentation, contact your local dealer.

If you need to contact Trimble technical support:

1. Go to the Trimble website (www.trimble.com).

2. Click the
A–Z list of products appears.

3. Scroll to the bottom of the list.

4. Click the

5. Complete the form and then click

Alternatively, you can send an e-mail to

[e-mail]

1.1 Your Comme n t s

Your feedback about the supporting documentation helps us to
improve it with each revision. E-mail your comments to

[e-mail].

2 NetRS Receiver User Guide

Support button at the top of the screen. The Support

submit an inquiry link. A form appears.

Send.

CHAPTER

2

Overview 2

In this chapter:

Q The Network Appliance Concept

Q NetRS Services

Q Use and Care

Q Electronic Interference

Q Security Threat (COCOM) Limits

NetRS GPS Receiver User Guide 3

2 Overview

This chapter introduces the NetRS GPS receiver. This receiver makes
it easy to deploy a powerful, flexible, and reliable Continuously
Operating Reference Station (CORS).

The NetRS receiver integrates the latest dual-requency GPS
technology into a Linux processing and communications framework
that can operate as a stand-alone reference station or can be integrated
into a scalable network.

Because Internet Protocol (IP) is 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 – In this manual, all references to the “Internet” mean either a
wide area network (WAN) or a local area network (LAN) connection.

The Linux framework provides a foundation that allows Trimble to
extend and customize the system in ways which are not possible with a
proprietary operating system. Native support for standardized
interfaces means that you can use a variety of powerful commercial
and public domain software to work with the NetRS receiver.

You can enforce multiple levels of security, from a completely open
system that allows anonymous access to all features, to a secured
system that requires a password protected login for configuration
changes and/or file access.

Use the network management features to:

• Store the configuration of one receiver to a file and restore it to
the same receiver at a future date, or clone it to any other
receiver in a network.

4 NetRS GPS Receiver User Guide

• Create a base configuration with a variety of operating modes.
You can then enable those modes as necessary, rather than
having to change the global state of the receiver from one mode
to another. For example, you can configure a number of
streaming services with different measurement intervals or
smoothing controls 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.

• Create multiple continuous logging session configurations and
then enable them only when required.

These features, and many more, shift the model of a GPS receiver
toward the concept of a “network appliance”.

2.1 The Network Appliance Concept

Traditionally, a GPS receiver has one user (operator). That person can
change settings without affecting other users.

Overview 2

With the NetRS receiver, an operator can configure the receiver once,
then make the receiver available, as a network appliance, for use by
one or more other users (clients).

An operator can set up the receiver to provide one or more services
that are accessible to one or more clients through the Internet. Once
the receiver is deployed, the client need make only minimal changes,
if any, to the receiver configuration.

When the receiver operates as a network appliance, it provides
services to all clients who are attached to the receiver through the
network.

Different streamed services can be configured on different ports. For
example, the service configuration on one port can have different data
rates or smoothing configurations from the service configuration on
another port. To obtain a service, the client has only to connect to a
specific port. In this way, most clients do not need to control the

NetRS GPS Receiver User Guide 5

2 Overview

receiver. Any changes the operator makes to global settings, such as
masks, affects all clients of all services. However, the comprehensive
set of controls that has been provided for streamed service and data
logging configuration avoids global changes for the majority of
applications.

The NetRS receiver provides the following standard configuration and
data logging services:

Use ... to perform ...

FTP remote manual and/or automated operations to manage the

HTTP

HTTPS the same functions as the HTTP link, except that all data that is

2.2 NetRS Services

logged data file space

all manual and automated configuration operations

manual operations to manage the logged data file space

sent between the office computer and the receiver is
encrypted, which makes the link more secure.

The receiver can provide one or more streaming or query services over
an RS-232 serial port or a TCP/IP port:

• Protocol service

A protocol service provides functionality over a two-way link.
PPP enables IP communications over an RS-232 serial link;
Trimcom is a binary protocol used by Trimble PC software
applications; Met-Tilt provides sensor query and data logging.

• Streaming service

Any client with authorized access can obtain streamed
information, such as GPS 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.

6 NetRS GPS Receiver User Guide

Overview 2

• Query service

No command is required; opening the TCP port triggers data
transmission. A query service provides a single source for a
specific information type, and returns it without affecting other
continuous streams.

Multiple clients can connect simultaneously to a single
streaming or query port.

The NetRS receiver supports the following services:

Service Description Type

PPP

(Point to Point
Protocol)

Trimcom This service supports a subset of the standard Trimble

RT17 This service can be configured to provide various

BINEX The BINEX service provides streamed GPS observables,

This service is the Internet standard for transmitting IP
packets over serial lines. When you enable the serial port
for PPP, you can run the NetRS web configuration interface
over the serial port.

“Tr i m co m ” binary communications protocol. Trimcom is
used by Trimble software applications for configurable GPS
data streaming and queries.

combinations of real time GPS measurements, including
phase, pseudorange, carrier-to-noise ratios, and other
general information about each satellite that is tracked.

“RT17” is also the real-time streamed GPS measurement
information. It includes the same information that is stored
in Type 17 records in T00 and DAT files This is the basic
information used to produce GPS positions and
corrections.

satellite orbits, and various optional data about the site and
receiver. For more information about the BINEX format, go
to http://binex.unavco.org/.

Protocol

Protocol

Streaming

Streaming

NetRS GPS Receiver User Guide 7

2 Overview

Service Description Type

Met-Tilt This service can be configured to send one or more device

initialization and query strings on a regular basis to obtain
measurements from external sensors. These sensors
include those used to collect meteorological data and/or
deformation data (where the tilt of the sensor is measured).
Data from the Met or the Tilt sensor is included in any
active RT17 or BINEX stream.
Depending on whether you are logging or streaming data,
all data is included in T00, BINEX, or RT17 format.

RTCM This RTCM (Radio Technical Commission for Maritime

Services) service can be configured to send one or more
RTCM SC-104 messages from the specified port.

CMR/ CMR+ This service can be configured to provide real-time GPS

measurements in Compact Measurement Record format,
primarily for RTK applications that use CMR or CMR+.

Ephemerides This service provides a complete set of GPS ephemerides

(orbits) each time an application connects to the selected
port.

Almanacs This service provides a complete GPS almanac each time

an application connects to the selected port.

SV Status This service provides a variety of information about the

current GPS and WAAS/EGNOS constellation.

Protocol

Streaming

Streaming

Query

Query

Query

8 NetRS GPS Receiver User Guide

2.3 Use and Care

The NetRS receiver is designed to withstand the treatment and
environment that typically occurs in a CORS installation. However,
the receiver is a high-precision electronic instrument and should be
treated with reasonable care.

Overview 2

C

2.4 Electronic Interference

Caution – Operating or storing the NetRS receiver outside the specified
temperature range can damage it. For details, see Specifications,
page 70.

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.

Do not locate the receiver or antenna within 400 meters of powerful
radar, television, or other transmitters, or GPS antennas. Low-power
transmitters, such as those in cell phones and two-way radios,
normally do not interfere with NetRS receiver operations.

2.5 Security Threat (COCOM) Limits

The U.S. Department of Commerce requires that all exportable GPS
products contain performance limitations so that they cannot be used
in a manner that could threaten the security of the United States. The
following limitations are implemented on the NetRS receiver:

Immediate access to satellite measurements and navigation results is
disabled when the receiver velocity is computed to be greater than
1000 knots, or its altitude is computed to be above 18,000 meters
(approximately 59,000 ft). The receiver GPS subsystem will reset until
the security threat (COCOM) situation clears. As a result, all logging
and stream configurations will stop until the GPS subsystem is
cleared.

NetRS GPS Receiver User Guide 9

2 Overview

10 NetRS GPS Receiver User Guide

CHAPTER

3

Features and Functions 3

In this chapter:

Q Features of the Receiver

Q Button Functions

Q LED Functions

NetRS GPS Receiver User Guide 11

3 Features and Functions

This chapter describes the physical features of the NetRS receiver. It
also describes how to perform some basic receiver functions.

3.1 Features of the Receiver

All operating controls, ports, and connectors on the receiver are on the
front or the rear panels, see Figure 3.1.

Front panel

Rear panel

Figure 3.1 Receiver front and rear panels

12 NetRS GPS Receiver User Guide

31.1 Front panel

Figure 3.2 shows the features on the front panel. The following tables
describe the features. For more information, see Button Functions,
page 18 and LED Functions, page 22

Features and Functions 3

.

DE9 connector

Ethernet

External
frequency

Figure 3.2 Front panel features

Satellites

LEDs

Logging

Power butto n

Secondary
power

Primary
power

Feature Description

DE9 port Provides a service port for initial Ethernet address configuration and

diagnostics. The service port uses a 3-wire connection with default
parameters of 115,200 baud, 8-NONE-1. Linux diagnostics are
available through this port during the boot and shutdown processes.

Power button Controls the receiver power states

NetRS GPS Receiver User Guide 13

3 Features and Functions

LED indicator shows...

External frequency external oscillator activity

Ethernet Ethernet port activity

Satellites satellite tracking status

Logging logging status to the internal memory

Primary power power status on the primary power port

Secondary power power status on the secondary power port

31.2 Rear panel

Figure 3.3 shows the rear panel features. Serial ports can support
RT-17 and BINEX data formats (to stream real-time GPS
observables), and CMR and RTCM data formats (to stream
RTK/differential corrections). Each port can also act as a PPP server
for IP communications over a serial link.

All supported configuration, streaming, file transfer, and firmware
update capabilities are supported over the Ethernet port or any serial
port supporting IP communications using PPP.

14 NetRS GPS Receiver User Guide

Features and Functions 3

Antenna (N)

External
frequency

(BNC)

Figure 3.3 Rear panel features

Port 2 (DE9 M)

Figure 3.4 shows the multi-port adapter in detail.

.

Power
connection

Por t 3 (DE9 F)

Port 4 (DE9 M)

Multi-port adapter
Primary power /

Ethernet (DA26-M)

1PPS output
(BNC)

Secondary
power (Conxall)

Ethernet
connection

Figure 3.4 Multi-port adapter detail

NetRS GPS Receiver User Guide 15

3 Features and Functions

Table 3.1 Rear panel features

Feature Description

N connector Connects to the GPS antenna.

Multi-port adapter

(DA26 male port)

BNC ports (two) One PPS output.

DE9 male ports
(two)

DE9 female port Connects to a DTE device, such as a computer.

Note – The 3 rear panel ports include full 9-pin connections that provide all the signals required to
support a modem or other communications device. A serial port can be configured for either direct or
modem connections. A modem connection supports all the signals necessary for auto-answer operation
using the Linux communication protocol, mgetty daemon. For more information, see Cables and
Connectors, page 73.

Primary power port – AC-to-DC power supply connects through an inline
DC power jack.

Ethernet port – connects to a 10Base-T network through an RJ45 jack.

External frequency input.

Connects to a DCE device, such as a modem or a terminal adapter.

2-pin Conxall
connector

16 NetRS GPS Receiver User Guide

Secondary power port.

Backup battery power connects through a DC power cable (P/N 48600).

31.3 Power ports

The NetRS receiver has two power ports:

• Primary – connects to the DA26 connector on the rear panel
through an inline DC power jack on the multi-port adapter.

Intended for use only with the Trimble AC-to-DC power supply
(P/N 48800-00).

• Secondary – connects to the 2-pin Conxall connector through
the DC power cable with polarity indications (P/N 48600).

Intended for battery backup using a nominal 12.6 V lead acid
battery system with any type of charging configuration.

Trimble recommends that you use a minimum 20 Amp-hour lead acid
battery in backup power configurations. A 20 Amp-hour battery will
provide over 60 hours of backup power, or about 30 hours with 50%
derating, if the receiver and antenna are the only powered devices.

If you use an external low voltage disconnect (LVD), set the NetRS
receiver shutdown voltage so that the LVD does not switch off while
the receiver is powering down. Do one of the following:

Features and Functions 3

C

• Set the shutdown voltage to at least 0.3 V above the LVD
disconnect voltage. Trimble recommends this setting to enable
the receiver to shut down normally.

• Set the shutdown voltage to at least 0.3 V below the LVD
disconnect voltage.

A large capacity battery will provide longer backup time. Trimble
does not recommend that you use a small capacity battery. Any battery
charging system must match the selected battery size.

Caution – Do not exceed the power supply voltage specification.
Use only AC power supply (P/N 48800-00) with the NetRS receiver.

NetRS GPS Receiver User Guide 17

3 Features and Functions

3.2 Button Functions

The NetRS receiver has only one button, the Power button, which is
on the front panel. The function of this button is to turn the receiver on
(press the button once) and off (press and hold the button for two
seconds). If you turn the receiver off using the
receiver will stay off, regardless of any alarm settings you may have
made. To turn the receiver on again, you must use the
remove and then reapply power to the receiver.

32.1 Power button operations

• When the receiver is switched on and operating, press the

Power button for at least 2 seconds, but not more than 10

seconds, to switch the receiver off. All LEDs, except the
Ethernet LED, turn off briefly when the receiver accepts the
button press.

Power button, the

Power button or

• When the receiver is off, press the
receiver on.

The NetRS receiver requires time to start up and shut down. It
can take from 75 seconds to 4 minutes to fully start up the Linux
operating system, depending on the previous shut down
conditions.

To turn off the receiver, press and hold the power button for two
seconds. The shut down process normally takes between
20 seconds and 1 minute. During these operations, all the LEDs
flash.

Once you have pressed the
to complete before you press the button again.

18 NetRS GPS Receiver User Guide

Power button once to turn the

Power button, wait for the operation

32.2 Power saving mode

Use the power saving mode to set options that control whether the
receiver remains on continuously or goes to sleep between data
logging sessions. This feature is particularly useful for sites with
intermittent power or where batteries are used and charging.

Sleep mode

In Sleep mode, the receiver switches to low power when there is no
active data logging session. This allows for extended operation when
the receiver is running on battery power.

Failsafe wakeup alarm

When the receiver is in Sleep mode, you cannot communicate with it
until the receiver wakes up for the next scheduled session. To avoid
problems if there is no future session defined, use the Failsafe wakeup
alarm. This activates the receiver for a short period at specific times
every day.

To control Sleep mode, select Data Logging and then set the following
controls as required in the Power Saving screen or the Status screen:

Features and Functions 3

• Shut down receiver between data logging sessions?

– Select Yes for the receiver to go into the power saving

mode when there are no active sessions. Once the receiver
is in this mode, you cannot communicate with the receiver
or use the browser interface until the receiver wakes up.

– Select No to disable Sleep mode. The receiver remains

active between sessions.

• Wake up periodically?

– Select Yes for the receiver to wake from Sleep mode for a

short time at one or more periodic intervals every day,
regardless of the need for a data logging session. This
option allow you to establish communications with a
receiver when there is no data logging session scheduled.

NetRS GPS Receiver User Guide 19

3 Features and Functions

Specify the duration of the wakeup alarm, and the interval
between alarms, from a range of values. The wakeup times
are always synchronized to the beginning of the UTC day.
For example, if you specify an 8 hour interval, then a
periodic wakeup alarm will occur every day at 00:00 UTC,
08:00 UTC, and 16:00 UTC.

C

32.3 Other power operations

Caution – If you turn off the Failsafe wakeup alarm, you may not be able
to communicate with a remote receiver.

Note – If you press Power while the power saving mode is enabled
and the receiver is in Sleep mode, the receiver temporarily turns on. If
there is no session pending, the receiver continues to operate for five
minutes, then automatically shuts down. If you visit the NetRS home
page for the first time during such a “hold off” period, a dialog
appears to warn that the receiver is scheduled to shut down after the
hold off time.
If you press
receiver is on, power saving mode is disabled and the receiver turns
off.

• If you disconnect all power sources, the receiver shuts down. It

• The receiver turns on only if at least one of the power supplies

Powe r while the power saving mode is enabled and the

automatically turns on again when you reconnect a power
source of 12 V or more. The receiver may take longer to boot up
when power is restored after a sudden power loss.

supplies 12 V (or more) power.

However, when the receiver is on battery power, you can turn it
off, or put it into Sleep mode, if the voltage is more than 11 V.

• When you use a standard AC power supply, or a battery that is
providing at least 12 V (that is, charged to at least 40-50% of
capacity), the
switch to boot up or shut down the receiver.

20 NetRS GPS Receiver User Guide

Power button will always function as an on/off

32.4 To erase the almanac and the ephemeris

You can erase the almanac and the ephemeris when they are out of
date:

Features and Functions 3

1. Press and hold down the

Power button for 15 seconds. The

External Frequency LED turns on.

2. Once you release the

Power button, the almanac and ephemeris

are erased.

30.1 To reset the receiver to factory defaults settings

C

Caution – The reset operation can take 5 to 10 minutes. Wait until the
receiver has returned to normal operation before you press the Power
button or disconnect receiver power. With the antenna connected, wait
until the Satellite tracking LED blinks to indicate normal tracking.
Alternatively, connect an office computer to the service port and wait until
the diagnostics output displays Switching to runlevel: 5.
The default IP addressing mode is DHCP. If the receiver is configured with
a static IP address, resetting to factory defaults may cause the receiver IP
address to change and result in loss of communications with the receiver
over the Ethernet link.

1. With the receiver switched on, press and hold the Power button
until the External Frequency LED turns on (at 15 seconds) and
then turns off (at 30 seconds).

2. Once the External Frequency LED turns off, release the
button.

The receiver performs a full reset. All parameters, including
GPS orbit and tracking information, are restored to the factory
default values.

NetRS GPS Receiver User Guide 21

Power

3 Features and Functions

3.1 LED Functions

The six LEDs on the front panel of the receiver indicate various
operating conditions. An LED that is constantly lit or is flashing
slowly usually indicates normal operation. An LED that is flashing
quickly indicates a condition that may require attention. An LED that
is unlit indicates that no operation is occurring. The possible LED
states are:

LED state Description

Flashing
slowly

Flash
quickly

Blinking LED is on for 1 second every 5 seconds

Off LED is not lit

On LED is continuously lit

31.1 LED startup sequence

LED is on for ½ second and off for ½ second

LED is on for 0.1 second every 0.2 seconds

When the receiver switches on, all LEDs turn on for a few seconds,
flash until the boot up process is complete, then operate normally.

The LED startup sequence shows if the receiver has started
successfully. When you switch on the receiver, the LED startup
sequence is:

1. All LEDs turn on briefly.

2. All LEDs turn off.

3. LEDs operate normally.

If the LEDs do not turn off, it means that the system has failed to start
correctly.

Note – On startup, LEDs flash from 20 seconds to 4 minutes,
depending on the cause of the previous shutdown. Receiver shutdown
due to a sudden loss of power will force a data file system integrity

22 NetRS GPS Receiver User Guide