External Instruments (NMEA0183)

When you subscribe to the TZ iBoat Essential plan, TZ iBoat allows you to receive data from external instruments such as NMEA Wi-Fi gateways, Furuno NavNet MFDs, or TZ Navigator / Professional, provided they are connected to the same Wi-Fi network. With an active Essential subscription, the Instrument Connections page displays a default set of preconfigured data sources:

  • My Gateway (pre-configured to listen on UDP Port 10110)

  • NavNet MFDs (pre-configured)

  • TZ Professional / Navigator (pre-configured)

  • Internal GPS (always present)

When configuring a NMEA Gateway, TZ iBoat can currently decode the following NMEA0183 data over TCP or UDP:

  • Position (GLL, GGA, RMC, VDO)

  • Course and Speed Over Ground (RMC, VTG, VDO)

  • Heading (HDG, HDM, HDT, VHW, PFECATT, VDO)

  • Depth (DBT, DPT)

  • Wind (MWV, MWD)

  • Sea Surface Temperature (MDA, MTW)

  • AIS (VDM) (*)

(*) AIS targets can only be displayed if you have subscribed to the optional AIS subscription.

IMPORTANT: TZ iBoat is compatible with navigation data transmitted using NMEA0183 sentences over a network connection. It does not communicate directly on an NMEA2000 bus. However, many modern NMEA Wi-Fi gateways are designed to connect to an NMEA2000 network and internally convert NMEA2000 PGNs into equivalent NMEA0183 sentences before transmitting them over Wi-Fi. When such a gateway is used, TZ iBoat receives standard NMEA0183 data and can display and process the information as expected.

Adding or Editing Instruments

In most cases, an NMEA gateway creates its own wireless access point. The device running TZ iBoat must be connected to this Wi-Fi network. Once connected, refer to the gateway manufacturer’s documentation to determine how navigation data is transmitted over the Wi-Fi network (TCP and or UDP, Port Number, and IP address).

To configure the instrument in TZ iBoat, open the Settings → Initial Setup → Instruments Connections.

Additional instruments can be added by tapping “Add Source”. You can also modify the pre-configured “My Gateway” entry by selecting it from the list, which opens the Instrument Configuration page.

IMPORTANT: NavNet MFDs and TZ Professional / Navigator do not require any user configuration. These instruments are pre-configured automatically, and TZ iBoat will automatically detect and receive available data when they are connected to the same Wi-Fi network. Please refer these chapters Furuno TZtouch 2, TZtouch 3 and TZT XL and TZ Navigator & Professional for more information to their integration.

When configuring a UDP connection, only the port number used by the gateway needs to be specified. When configuring a TCP connection, both the IP address (or hostname) and the port number used by the gateway are required:

NMEA Gateway

When configuring a TCP connection, TZ iBoat automatically proposes an IP address based on the current network configuration, which in most cases corresponds to the gateway address. To ensure this works correctly, make sure your device is connected to the gateway’s Wi-Fi network before configuring the connection in TZ iBoat. Note that the TCP protocol is required when sending navigation data to an autopilot, and selecting this protocol enables additional pilot output and configuration options (see the Autopilot Connection) chapter for more information.

 

IMPORTANT: When an NMEA gateway supports both UDP and TCP, the choice of protocol depends on your platform and intended use. UDP is generally easier to configure because it does not require specifying the gateway’s IP address, making it a convenient option when only receiving data. TCP provides a more reliable connection and is recommended on Android devices, where UDP data may not be processed when the application runs in the background. TCP is also required when TZ iBoat needs to send data back to the gateway, such as for an autopilot. One additional difference is that a lost TCP connection will trigger a warning in TZ iBoat. This behavior can be inconvenient when leaving the boat and disconnecting from the gateway, but it can also be seen as an advantage by clearly alerting you when the connection is no longer available. As a general guideline, UDP is recommended on iOS when no autopilot is used, while TCP should be preferred on Android devices or whenever autopilot output is required.

Each instrument displays a real-time status indicating whether it is connected (for TCP connections) and whether data is being received (for both UDP and TCP). For troubleshooting, each instrument provides access to a Port Monitor, which displays the raw NMEA0183 data stream received on that connection. The Port Monitor shows the most recent data, allows the display to be paused or resumed, and includes an option to share the log which can be useful to analyze the raw NMEA data:

 

IO_PortMonitor

If no data appears to be received, check the following:

  • Make sure your device is connected to the correct Wi-Fi network, which is usually the network created by the NMEA gateway. TZ iBoat displays the name of the currently connected Wi-Fi network next to "Selected Wifi" (just under the “Protocol” section).

IO_IPStatus

  • Verify that your device has obtained a valid IP address. If the Current IP Address starts with 169.254, this usually means the gateway was unable to assign an address. In this case, disconnect from the Wi-Fi network and reconnect. The current IP address of your device is displayed just under “Selected Wifi” (ex: 192.168.1.101)

  • For TCP connections only, confirm that the TCP IP address configured in TZ iBoat matches the IP address of the NMEA gateway. The gateway address typically ends with “.1”. For example, if your device’s IP address is 192.168.1.101, the gateway address is likely 192.168.1.1. This information should be verified in the gateway manufacturer’s documentation.

  • For both TCP and UDP connections, ensure that the port number is correct. Refer to the gateway manufacturer’s documentation for the appropriate port, which is commonly 10110, 2000, or 60001.

IMPORTANT: When a connection error occurs, TZ iBoat displays a message describing the issue and, when possible, provides guidance to help resolve it. These messages may indicate that the selected port is already in use by another application, that the device is connected to an incorrect Wi-Fi network, that no device is detected at the specified address, that the connection was refused by the remote device, or, on iOS, that local network access permissions are not enabled.

TZ iBoat continuously monitors instrument connections for incoming data. If data stops flowing, "Data Lost" is displayed in the port status. You can also enable a warning by turning on "Warn when data feed stops" in the instrument configuration page. When this option is enabled, TZ iBoat displays a warning message reading "Data Lost on [Instrument Name]" if no data is received from that instrument for 15 seconds.

Enabling, Disabling, and Prioritizing Instruments

Enabling or disabling Instruments

Each instrument in the list can be enabled or disabled using the toggle displayed next to its name:

IO_EnableInstruments

This is particularly useful when your device is connected to a different Wi-Fi network (when a TCP connection generates errors) or when you want to temporarily ignore a specific data source without removing it.

Adjusting Instruments priority

Instrument priority determines which data source is used when multiple instruments provide the same type of information. Instruments are processed from top to bottom in the list, with instruments positioned higher in the list taking precedence over those below.

To change the priority order, tap “Reorder Sources” and rearrange the instruments as needed:

IO_Priority

Newly added instruments are automatically placed at the top of the list (highest priority by default).

IMPORTANT: The Internal GPS always remains the lowest-priority source and cannot be moved.

Damping and Offset

When using an external GPS through an NMEA gateway, GPS speed and course values may update frequently, which can cause ETA and TTG calculations to fluctuate. To reduce this effect, you can apply damping to Course Over Ground (COG) and Speed Over Ground (SOG) in the Settings → Initial Setup under Damping. Increasing the COG and SOG damping values increases the averaging time, resulting in smoother data and more stable ETA and TTG at the expense of slower response.

If wind data is provided by the NMEA gateway, you can also apply damping and offsets to wind speed and wind direction from the same settings page.