Product support: A200

On a Class A AIS device, you typically enter only one set of ship dimensions, not both internal and external. Here’s how this works in detail:

1. Dimensions Required for AIS Configuration

Class A AIS transceivers require the entry of the vessel’s dimensions as part of the static data transmitted periodically to other vessels and coastal stations. These dimensions are:

• A = Distance from GPS antenna to the bow
• B = Distance from GPS antenna to the stern
• C = Distance from GPS antenna to the port side
• D = Distance from GPS antenna to the starboard side

These measurements define the position of the GNSS antenna relative to the vessel’s hull and are used by receiving systems (like ECDIS or ARPA) to graphically represent the ship’s size and orientation.

2. No Separate “Internal” and “External” Dimensions

There is no concept of “internal” and “external” dimensions in AIS configuration. The system uses one set of dimensions only, regardless of whether:

• The GNSS antenna is internal (built into the AIS) or external (connected from another source)
• The AIS is integrated into a larger ship system or operates independently

What matters is where the active GNSS antenna is located, and the vessel dimensions must be entered accordingly.

3. Practical Tip

If switching between internal and external GNSS sources (e.g., between a built-in and a bridge-top antenna), you should update the dimensions (A, B, C, D) to reflect the position of the currently used antenna relative to the ship’s hull.

You only need to enter the internal dimensions.

A VSWR alert may appear if the VHF antenna isn’t working properly. A good VSWR is 3:1 or less.

Common causes:

• Loose or faulty cable/connectors

• Antenna near metal surfaces or other antennas

• Antenna not tuned for 162 MHz AIS frequency

Use an AIS-tuned antenna and check all connections for best performance.

Please ensure you have connected the supplied GPS antenna. Other GPS antennas may not be compatible so please contact support@em-trak.com if you are in doubt.

The GPS antenna should be mounted high with a clear view of the sky, although ideally not on top pf a mast as the pitch and roll may affect the transmitted position. It needs to be out of the direct path of RADAR or satellite communication antennas, and as far away as practical from transmitting antennas that may interfere with the signal.

• Ask a nearby AIS vessel if they can receive your signal—AIS websites may not show real-time data.

• Look for the up arrow icon on the A200 display—it appears periodically when transmitting.

• To test communication:
  Go to Home > System Settings > Advanced > Installation & AIS SART Test, then select a vessel to send a test message and check for a reply.

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If AIS is supported but no targets appear, check NMEA 0183 wiring:

• Connect positive to positive (A/+)

• Connect negative to negative (B/-)

• Match transmit to receive, and vice versa

• Set baud rate to 38,400 for AIS (lower rates may drop messages)

Need help? Contact 📧 support@em-trak.com

AIS tracking sites get their data from AIS receivers that are installed along coastlines as well as satellites. Satellites receive a very low percentage (<2%) of transmissions from standard AIS transceivers and have many blind spots. Therefore tracking sites do not provide full coverage, at times their reception range is variable, may drop out entirely and their data refresh rate cycles and latencies can be very slow.

The best way to check your AIS is working correctly is to ask a nearby vessel with AIS if they can see you.

The ‘modem not responding’ error will be displayed if:

• the software needs to be updated. Please download the latest software update package here – https://productsupport.em-trak.com/hc/en-gb/articles/28856175410973-PCN-63-A200-Software-update-Impaired-Radio

• the unused ports need to be terminated (this only applies if you’re using the 14-way or 18-way cables). The ports can be terminated by adding 120 ohm resistors between the RXA and RXB wires, as per the recommendation in the user manual, or by installing the optional junction box.

  

If the error is not resolved by following the above, please contact us at support@em-trak.com

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Non-AP mode(Client)

To get the A200 transmitting in Non-AP mode(Client);

• Connect the A200 to the WiFi network
• Then connect the laptop or device you want to be streaming the NMEA data also to the same WiFi Network
• Finally either using Hyper Terminal or AIS application such as Navionics etc, connect to the IP address that’s been assigned by the WiFi access point you connected to. In the example below 192.168.43.100 via DHCP being enable.

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Alternatively you can change the DHCP option to disable and use the IP address that you’ve set initially.

You should now have AIS data streaming from the AIS unit to your device.

AP mode(server)

To get the AIS transmitting in AP mode(server);

• ​​Change the WPA-2 password to what you want.
• Make sure protocol is set to TCP and DHCP is enabled
• Change the IP address and Port number if needed or leave the default in place
• Go to your connecting device, like phone, iPad, laptop etc and you should see the AIS’s SSID listed. In my example – Class A AIS 0039
• Connect to the SSID with the password you changed in the first step.
• Finally either using Hyper Terminal or AIS application, connect to the IP address. In the example below 192.168.50.1 with Port number 49200.
• You should now have AIS data streaming from the AIS unit to your device.

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• em-trak_A200_Pilot_Plug_to_PI2_Wiring_v4.pdf (472 KB)

The English A200 user manual can be downloaded below.

• 201-0687_em-trak_A200_user_manual_EN_v9.pdf (4422 KB)