FAQ

What is AIS?

Automatic Identification System is a ship reporting system. The majority of ships these days are required to fit an AIS transponder so that they automatically transmit data to enable other users to receive this information.

Click here for a full description of the system.

What are the benefits of fitting an AIS Receiver?

With an AIS receiver onboard connected to either a compatible Chart Plotter or PC Charting program you can view other vessels within VHF radio range and establish such information as name, current position, course and speed.

This information can then be used to assist safe navigation.

Why are all your Receivers Dual Channel Parallel?

To ensure that you receive the most up to date information quickly.

Single channel or multiplex receivers will only on average receive half the number of transmissions from other vessels so not giving you a true position of their current location.

What is involved in installing an AIS Receiver?

The AIS signals operate in the VHF marine so the receiver will either need its own VHF Antenna installed, or you can use the Comar ASR 100 antenna splitter that allows you to share your existing VHF Radio antenna with the AIS Receiver.

The data output from the Receiver then needs to be connected to a Chart Plotter via the NMEA cables, or to a PC by the Serial or USB connections.

What NMEA data is sent?

All our receivers output the NMEA message type VDM. By default this is sent at the speed of 38400 baud so your Chart Plotter or PC program must be configured to receive the data at this speed. On some of our receivers you can change the output to 4800 baud.

What range will I receive information from?

AIS reception will be similar to your existing VHF radio reception, typically a minimum of 20 miles in open waters. It has the same characteristics as normal VHF regard its “line of sight” therefore the higher that you place the antenna the larger the range.

Why do the ships names take longer to be displayed?

Information is sent in different message types, the basic information of MMSI, position, course and speed are sent frequently so this information shows first.

The name of the vessel, type of vessel, destination etc are sent less frequently so this information takes longer to show on your display.

What are the advantages of installing a CSB 200?

With the CSB 200 you are not only receiving all the data but you are also transmitting your own vessels information so that others can see you.

What is involved in installing a CSB 200?

Installation of the CSB 200 is similar to the receive only units in the fact that you either need a dedicated VHF antenna, or you can use the AST 100 Antenna splitter that is designed to cater for 2 possible transmitters at a time sharing your single VHF radio antenna. The CSB 200 transmits its position that is obtained from its own internal GPS, so installation of a separate GPS antenna is required, such as the AG 100.

Can I use NMEA data from my existing GPS for the CSB 200?

No, the internal GPS of the CSB 200 must be operating to ensure synchronisation with the AIS network as well as positional information. The CSB 200 will not accept any GPS NMEA data input.

How do I enter my MMSI number, name etc into the unit?

The CSB 200 is shipped with a CD that contains a PC program. Connecting the CSB 200 to a PC via the Serial port or user supplied Serial to USB adaptor allows you to enter all the static data into the unit. Once the data is entered, the unit retains this in its memory and will operate as a standalone unit if required.

How do I change the MMSI number that is already set in the unit?

Once programmed, the MMSI number cannot be changed by the end user.
If the MMSI number needs to be changed in any way, the unit must be returned to COMAR SYSTEMS or one of our authorised dealers. Please contact COMAR SYSTEMS to obtain an RMA number for this procedure.

How often does the CSB 200 transmit?

The CSB 200 transmits its static data, i.e. name, call-sign, type of vessel and dimensions once every 6 minutes, and its dynamic data, i.e. position, course and speed once every 3 minutes if travelling 2 knots or less, and once every 30 seconds if travelling faster than 2 knots.

The Timeout and Error LED’s are on, is it faulty?

No, both these LED’s will stay on until you program your MMSI number into the unit. Once the MMSI number has been programmed, and after powering up the unit, the Timeout LED will stay for a few minutes whilst the GPS acquires satellites then this will extinguish and the green Status LED will light.

The Timeout LED occasionally comes on?

This will happen and is indicating that the unit was unable to transmit at its specified time, the reason normally is the GPS momentarily lost signal, or the time slot that the unit was going to transmit in was already occupied by a Class A transmitter that has priority. No operator intervention is needed and the unit will return to normal in a short time.

Other vessels cannot see me?

If the CSB 200 is not showing any Error or Timeout LED’s then it is probably transmitting your data. The static data which is sent, is in a new message Type 24, that has not been implemented in some Class A units and also in some display systems such as Chart Plotters. This means that they may not see your name, but they will see you as an MMSI number with your position, course and speed.