The Input/Output Summary page provides a summary of the currently
configured Input/Output ports, allows individual ports to enabled
and disabled, and acts as a gateway to allow creating or editing port
configurations. The term I/O port refers to one of the four
NetRS Serial Ports, or to any number of user defined TCP, UDP or REP
ports. Various functions (services) can be assigned to these
ports and configured for specific needs. Some functions are only
available on specific types of ports.
The primary information on the I/O summary page is a table listing all
currently defined ports and what type of service is being provided on
the port. The four serial ports will always be shown. In addition,
all user defined TCP, UDP or REP ports will be shown along with
the services being provided on those ports.
Each port has a corresponding Enable checkbox. When Enabled, the
service is available. When disabled, the service can no longer be
accessed. Clicking on the a checkbox will toggle the state of that
control. Port enables will occur immediately. Port disables will ask
for a confirmation from the user. Note that if you are accessing the
Browser GUI using a PPP port, and disable that PPP port, you can cut off
further access to the NetRS.
Clicking on the name of an existing port will switch to a page that
allows editing the service configuration on that port. Along the bottom
of the page are some buttons for creating new TCP, UDP or REP port
definitions.
Input/Output Services
There are a number of services that can be assigned to the Input/Output
Ports. Some of them are only available on specific types of ports.
For instance, PPP services are only available on the Serial ports. The
services can be roughly divided into four categories, as listed here:
- Streaming services
These services provide a continuous stream of data directed to
the specified port. For TCP, UDP, and REP ports, the stream may be used
by one or more clients who have all established a connection to the same
port.
- RT17
An RT17 stream contains real time GPS measurements, including
Carrier Phases, Pseudoranges, Signal to Noise ratios, and general
tracking information. RT stands for real time, and 17
refers to the record type 17 GPS measurements that are stored in
Trimble DAT and T00 files. This is the basic information used to
produce GPS positions and corrections.
- RTCM
An RTCM stream contains differential GPS correction data as defined
in the RTCM standards. Several different RTCM versions and styles
are supported.
- CMR
A CMR output stream contains real time GPS measurements in
Compact Measurement Record format, primarily for RTK
applications. Supports either standard or CMR-Plus formats.
- Binex
A Binex stream contains real time GPS measurements and other
information, encoded using the BINEX format as defined by
UNAVCO. It is used primarily for measurement logging applications.
- Query services
Ports that provide query services wait for a client to request data,
and then emit a single burst of data to that client. Query services are
only available on ports using the TCP protocol. A client requests the
data from the NetRS by making a TCP connection to the port. The data is
immediately returned and the associated connection is closed by the
NetRS. Typically, information provided via a query services changes
infrequently. The available query services are:
- Ephemerides
Emits the precise orbital parameters for all GPS satellites.
- Almanacs
Emits the approximate oribit information for all GPS
satellites.
- SV Status
When triggered, this service emits a packet containing
status indicators that show current information about:
- GPS Ephemeris availability.
- GPS Almanac availability.
- Disabled GPS satellites.
- GPS Satellite health information.
- GPS L1, L2 and code tracking information.
- WAAS tracking information.
- Interactive services
These services rely on an interaction between some external device
and the NetRS. There are two of these currently defined:
- Met-Tilt Service
The Met-Tilt service sends commands to one or more external
sensors and collects the responses for use in other output streams or
in logged data files. The Met-Tilt servie is available only on Serial
Ports. In a typical configuration the serial port is connected to
an external meteorological sensor and/or tilt sensor.
Measurements collected from these sensors is stored in internally
logged T00 data files or transmitted in RT17 or Binex output streams.
- Trimcomm Service
The Trimcomm service allows for interactive remote control of the
NetRS using a subset of Trimcomm commands that are used in other
Trimble GPS receivers. The Trimcomm service is available only on TCP
ports.
- PPP services
The Point-to-Point Protocol (PPP) is used to establish an IP Network
connection using an RS232 serial port. The serices are only available
on Serial Ports. There are two forms of PPP available:
- PPP (Dialin)
This form of PPP sets up a serial port as a PPP server. The Server
waits for an incoming PPP connection and sets up an IP connection
using the user provided configuration. This is commonly used to
to allow a PC running a PPP Client program to communicate with the
NetRS via a Browser, etc.
Note that the Graphial User Interface, Programmatic Interface, and
the Help pages refer to this service is simply as PPP.
- PPP Dialout
This form of PPP causes the NetRS to dial to an external Internet
Service Provider (or other PPP server) to establish a continuously
operational IP connection.