GNSS Receiver

A GNSS Receiver module controls the data received by the respective connected receiver. It also analyzes the consistency of multi-frequency data for each satellite. It detects receiver errors, such as data drifts, outliers or cycle-slips. If a cycle slip has been detected, the module tries to correct it. Data, which can not be corrected, is removed from the data set, before it is passed on to other modules. With active connections, external sensor data (weather, tilt data) can be stored.

Adding the GNSS Receiver module

GNSS Receiver modules are available from the Device Manager module. Trimble 4D Control Server accepts an arbitrary number of GNSS Receiver modules.

When the module is being added, the GNSS Receiver Properties dialog appears. It lets you define and select GNSS Receiver module configurations. Each configuration holds the decoder settings, the connection to the reference station receiver, and receiver data, such as the station information and receiver control.

If Trimble 4D Control Server does not find the receiver specified in the connection profile after a time limit of 5 seconds, the decoder will be loaded in a passive mode. Trimble 4D Control Server now waits for incoming data.

Tip - Before adding a GNSS Receiver module to the module-tree of Trimble 4D Control Server, make sure that the data transmission between receiver and the control center computer is working without problems.

An Ephemeris Manager module is automatically started when the first reference station receiver is connected.

Performing a plausibility check on reference coordinates

A calculation of the single point position of the receiver provides first information on the receiver position and its plausibility. Applying the SPP coordinates is an option, if known coordinates are missing.

Computation of dynamic station coordinates and station-dependent code bias calibration files

In a Real-Time Network system with RTX license, the parent Device Manager can be configured to compute dynamically updated station coordinates and code bias calibrations, using solutions provided by the Trimble Code Bias Calibration service. These coordinates will only be used by network processor modules. Use the Dynamic Station Coordinates view for viewing the current status of coordinates and optionally for resetting the coordinate calculation.

Status of the GNSS Receiver module

In the Tree view, each GNSS Receiver module is represented by its configuration name and a status-identifying icon.

	Connected to the device. Receiving data.
	Connected to the device with remote download decoder. Waiting for data.
	One of the following states related to receiver information: Pending changes of antenna/receiver settings (status: OK). Invalid receiver type (Infected status).
	Connected to the device, data flow suspended.
	Bad antenna settings, or no antenna model.
	Switched to backup connection.
	Data from less than 5 satellites available after the raw data analysis.
	Alarm status of the receiver. For example, of the following reasons: No data from the receiver. No dynamic station coordinates
	Disconnected from the device.

The module displays several module-view pages.

Depending modules

You can add the following modules to a GNSS Receiver module:

Router

Storage

Establishing and starting a backup connection

To make sure that the communication with your external data source, such as a reference station receiver, is working even after a breakdown of the main (primary) communication link, you can set up modules receiving data (such as GNSS Receiver, Router) for the use of a second hardware or software connection, the backup connection.

Receiver and antenna information handling - accepting pending changes

Incoming receiver data streams include information on the firmware and boot version and the serial number of the receiver device, as well as on the antenna type used and the antenna serial number. If the data stream contains such information that differs from the stored values, operators must accept pending changes before they become valid.

Connecting to the receiver's web UI

With actively connected GNSS Receiver modules and valid Receiver name and HTTP port settings in the Remote Access category of properties you can directly connect to the receiver's web UI doing the following:

Go to the Tree view and set the focus onto the GNSS Receiver module.
Select its shortcut menu item Connect to Web UI.

Alarming

With alarming activated, the GNSS Receiver module triggers alarms, if the following happens:

Backup connection lost
Incoming connection lost
No data from instrument
Pending changes of antenna/receiver settings: Incoming receiver and/or antenna information differs from the stored information, administrator interaction may be necessary.
Source of power supply changed (triggers, if the power supply changes from external to internal)
Switched to backup connection
Temperature exceeds threshold
Tilt angle exceeds threshold
Voltage falls below threshold

Logging into the database

All connection events are logged into the central database. The database contains the following tables, which can be filled in by several modules types:

Table name	Contents	More information
DriverConnections	Settings and events of incoming and outgoing connections.	One row for each module and each period it is connected.
DataOutages	Periods of missing data.	One row for each event. Logging into the database starts after a module-depending minimum data outage period.