Trimble NetRS - UNAVCO Basic Use Guide

Trimble NetRS - UNAVCO Basic Use Guide

UNAVCO, 2007

The purpose of this guide is to walk UNAVCO users through common tasks on the Trimble NetRS. A complete Trimble NetRS user guide is also available.

Table of contents:

A. Setting the receiver’s IP via the serial port.

B. Connecting to a NetRS via the web interface.

C. Configuring a NetRS via the web interface.

D. Creating and uploading a configuration file.

E. File downloading and deletion.

F. Troubleshooting.

Appendix A: Terminal emulators.

Appendix B: How to change the IP address of your computer.

The easiest way to communicate with and configure a NetRS is through its web interface. If you know the receiver’s IP address, skip to B. If not, proceed with A.

A. Setting the receiver’s IP via the serial port

If you do not know the receiver’s IP address or if the receiver is set to DHCP (factory default), do the following:

Now power up the NetRS (or power cycle it if it was already on).

B. Connecting to a NetRS via the web interface.

We assume here that your NetRS is set with a static IP. Your computer must be on the same network as the receiver; that is to say, your computer’s IP must have the first three numbers in common with the receiver’s IP. For instance, if your receiver is set to, your computer must be 192.168.1.x, where x must not be 2 (which is the address of the receiver). A good default in this case is For instructions on how to change your computer’s IP address, see Appendix B. Note that you will not be able to be on another network (wireless, LAN) while connected directly to a NetRS, so disable any active wireless connection.

An indroductory screen for the NetRS should appear in the web browser. If it does not, it is possible that the NetRS has not fully booted. The receiver generally takes about four minutes to boot. Try to refresh your web browser. Be patient.

C. Configuring a NetRS via the web interface.

All NetRS receivers coming from UNAVCO should have a standard UNAVCO configuration loaded unless the user has requested otherwise. The receivers are configured to have an IP address of, to log data at a 15 s sample rate into 24-hour files, to have an elevation mask of 0 degrees, and to not be password-protected.

System Name:

The system name (generally either the receiver’s serial number or the site’s 4-character ID) and the receiver’s serial number are displayed in the upper right-hand corner of the screen. A menu on the left allows you to navigate through receiver information and survey parameters. To change the system name, select Set System Name under Receiver Status – Identity.

Data Logging:

You may allot different amounts of storage to different sessions. For instance, your priority is 30 S continuous data logging to determine long-term deformation rates, but you would also like to record 1 Hz data in case there is an event such as an earthquake nearby. To do this:

Miscellaneous items in the Receiver Configuration menu:

Under Receiver Configuration, UNAVCO default settings are as follows: Clock steering enabled, multipath control disabled, L2C tracking disabled, one pulse per second disabled (this is output generally transmitted to time an external device), internal reference frequency, and shutdown voltage of 10.680 V (which is the Trimble default).

Antenna Setup:

Antenna information can be entered in the RINEX files after data collection. If you would like to enter the correct antenna type and height information into the receiver, you can do so under Receiver Configuration-->Antenna in the left-hand menu.

Masks (Elevation, PDOP):

The elevation mask determines to what angle above the horizon the receiver will collect GPS data. Errors in atmospheric delays increase as the satellites near the horizon. The UNAVCO default is 0º; additional data can be eliminated during processing.

PDOP (position dilution of precision) is a quantitative measure of satellite geometry. Low PDOP indicated good geometry (satellites distributed at differing azimuths throughout the sky) while high PDOP indicates poor satellite geometry (e.g. all visible satellites clustered in one part of the sky). We set the PDOP mask very high (at 50—good PDOP values are < 6) because we want the receiver to continue recording data regardless of satellite geometry.

Internet options:

You can change your receiver’s IP settings through the web interface. Note that you may have to change your computer’s IP settings accordingly (see B. Connecting to a NetRS via the web interface, above).

UNAVCO default settings for internet options are: IP address, MTU 1500, Netmask, Gateway, and Name Servers, Domain, and Search Path not set. HTTP Standard Port 80 enabled and HTTPS Standard Port 443 enabled, others disabled. IP Filtering disabled. Anonymous FTP enabled.

I/O (Input/Output) Configuration and the serial ports:

There are four serial ports on the NetRS: 1, which is in the front, and 2-4, which are in the back. 1 and 2 are straight connections, while 3 and 4 are null.


You can control access to the configuration of and the data on the NetRS by creating user accounts. Under Security-->Accounts in the left-hand menu you can create accounts and specify access for each. Note that an account is not needed to access the data via anonymous ftp. (Ftp access is controlled under Internet-->FTP on the left-hand menu.)

D. Creating and uploading a configuration file.

If you have many receivers that you want configured in a way that differs from the UNAVCO configuration, you may want to create, upload, and apply your own configuration file.

To apply your configuration file to another NetRS:

E. File downloading and deletion.

Files can be downloaded either via the web interface (convenient for a small number of files) or via ftp (convenient for a large number of files). File names are created automatically as [system name]+[year]+[month]+[day]+[start time]+[session ID], e.g. CCRI200706030000a.T00 for a file in the T00 format from site CCRI started at 00:00 UTC on June 3, 2007.

Downloading files via the web interface:

Downloading files via ftp:

To download files from the NetRS using ftp, you must:

  1. know the IP address of the NetRS, and, if not using a receiver configured with the UNAVCO configuration file,

  2. configure the NetRS to accept ftp connections.

If you do not know the IP address of the NetRS, see “A. Setting the receiver’s IP via the serial port” above.

To configure the NetRS for ftp communication:

To download files:

F. Troubleshooting.

To reset the receiver back to factory default settings:

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

OR (preferred) if you are able to establish a serial connection:

The receiver should reboot, reset to factory default settings and reload the kernel. As above, the receiver will be set to DHCP. No GPS data will be lost. All settings will be set to factory defaults; any saved sessions will be erased.

Appendix A: Terminal emulators

Hyperterminal comes with Windows automatically. Go to Start-->All Programs-->Accessories-->Communications-->Hyperterminal.

Mac users can download Z-term from


Enter a name and choose an icon for the connection.

“Connect to:” under “Connect using” select your comm port.

For Port Settings, select 115200 bits per second, 8 data bits, None for parity, 1 for Stop bits, and None for Flow control. -->OK

There are two phone icons under “View” in the window’s heading. One has the receiver down, meaning you are connected. In the other the receiver is raised from the phone, meaning disconnected. If you need to change your port settings, you must first click the disconnect icon. Then go to File-->Properties-->Configure.

Make sure you are connected (left-hand phone icon grey, not selectable).


Hold down the shift key and double-click the Z-term application. Select your comm port/ device (e.g. USB-serial adapter) and click OK. The baud rate, bits, and parity should be displayed at the bottom. To change these parameters, go to Settings-->Connection. Set parameters to 115200 for baud rate, none for parity, 8 for data bits, 1 for stop bits, and none for flow control.

Appendix B: How to change the IP address of your computer

If your computer is a PC, you should be able to do the following:

If your computer is a PC running Windows Vista:



Article ID: 38
Created: January 27, 2010
Last Updated: January 27, 2010
Author: Beth Bartel

Online URL: