DDCS Operational Features

Getting Started with DDCS

Enable DDCS target display:

Menu path

Quick settings → AIS Layer DSC Layer

DDCS Operating Principle

DDCS receives signals from radio stations with digital selective calling (DSC) functionality, as well as standard navigation data with a structure similar to AIS data.

Data reception features:

  • Data reception is possible only when the transmitting station is properly configured

  • Data transmission interval is determined by the settings of the encountered vessel’s radio station; by default, navigation data is transmitted only when a distress signal is sent or when the PTT button is pressed on the radio station

  • The absence of data reception from an encountered vessel via the DSC channel does not indicate a malfunction of your equipment or ECDIS

Tip

If DDCS targets are not displayed on the ENC, verify:

  • The DDCS sensor is configured and active

  • The DSC layer is enabled in the operational settings

  • The encountered vessel is transmitting data via the DSC channel with correct settings

Note

DDCS Target Display Settings

The system uses the same filtration and activation settings as for AIS targets. Visibility radius, auto-activation, class filtration, and approach criteria parameters configured in the AIS → Filtration and Activation section are also applied to DDCS targets.

DDCS targets are displayed on the chart upon data reception.

DDCS target vectors are displayed on the chart based on the data from their last received message, in accordance with ECDIS settings.

Target Activation and Deactivation

DDCS target activation and deactivation are performed in automatic and manual modes.

Automatic mode:

  • A DDCS target is automatically activated upon receiving the first message from the target, if the target is within the guard zone or when the target transmits a distress signal

  • The target is automatically deactivated (placed in “sleeping” status or removed) when messages from the target cease within the timeout period

Manual mode:

To forcibly activate/deactivate targets: hover the cursor over the target, right-click (press and hold) to open the context menu, select Activate or Deactivate. The target will be activated.

Context menu for DDCS target activation/deactivation

Target Information

View detailed information about a DDCS target:

  1. Select the target on the chart (left-click on the target symbol)

  2. The target will be highlighted with a frame on the chart

  3. The DSC Target tab will open in the Multifunction window with information about the selected target

DSC Target window with DDCS target information

DDCS target information

The following data is displayed in the DSC Target window:

  • Target position (coordinates)

  • Course (if transmitted)

  • Speed (if transmitted)

  • Target identifier

  • Last data update time

Important

Motion Parameter Display Limitations

DDCS target motion parameters (speed vector and course) are transmitted in the NMEA sentence $PNAVRIS. If the connected radio station does not support transmission of this sentence, DDCS target symbols will be displayed without vectors.

NSR ECDIS NES-3000 does not accumulate target data for calculating target motion parameters (TMP) based on historical data. Motion vectors are displayed only when transmitted in real time.

Warning

DDCS Message Requirements

DDCS target coordinates are transmitted in the NMEA message $--DSC. However, the same field may contain the data transmission channel and frequency instead of coordinates. The type of transmitted data depends on the radio station manufacturer’s settings.

If coordinates are not transmitted in the correct format, DDCS target display will not be possible.

For correct display and processing of DDCS targets, a complete set of NMEA sentences from the onboard radio station with DSC functionality is required:

  • $--DSC — target coordinates

  • $--DSE — extended target data

  • $PNAVRIS — target motion parameters

Lost Targets

When Lost Target is enabled in the AIS settings, targets from which no data is received within the set timeout will be marked as lost.

System behavior on target loss:

  • The lost target is removed from the chart

  • A lost target warning is displayed in the notification area

  • Warnings are generated only for active targets

Note

The lost target timeout is configured in the AIS → Filtration and Activation → Lost Target section. This parameter applies to both AIS targets and DDCS targets.