User manual NORTHSTAR M121

[. . . ] M121/M84 Multi-Function Unit Installation and Operation Manual www. northstarnav. com Contents 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1-1 Overview . 7 1-4 Removing and replacing the display unit . 8 2 Basic Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2-1 Using the keys . 11 2-2 Turning on and off / auto power . [. . . ] All vessels equipped with AIS permanently broadcast via one or more of the two dedicated VHF channels. This transmission may include information about the vessels MMSI-number, its call sign, name, position, course, heading, speed, rate of turn and type of vessel. This unit can receive and display AIS information when connected to an AIS receiver. Available AIS vessels transmitting in the local area are shown on the chart when this feature is enabled. The following AIS receivers are supported by this unit: · Comar SLR200 (external GPS). · Weatherdock Two Channel AIS Receiver "EASY AIS", Part No. · NASA Marine AIS Engine 2 channel Receiver (external GPS). Other AIS receivers may work but have not been tested with this unit. To enable AIS from the system menu check the AIS box. (see section 16-3) 16-1 Viewing AIS Vessels A typical AIS window shows: E B A C D A B C D E AIS Vessel Dangerous Vessel Projected Course Data Box Range Rings Northstar M121/M84 Installation and Operation Manual 57 When the cursor is placed over an AIS vessel for at least two seconds, a data box appears at the bottom of the window with information about the AIS vessel. For complete AIS information on the AIS vessel place the cursor over an AIS vessel for at least two seconds and press . Press either or to clear the information. 16-2 Dangerous Vessels The M121/M84 calculates the time of closest point of approach (TCPA) and closest point of approach (CPA) for each AIS vessel. This is used to determine potential dangerous vessels. If the TCPA and the CPA is below the trigger values then it will be considered dangerous. (See section 19-8 for setting the dangerous vessel alarm) A dangerous vessel is indicated on the chart by a red circle around the icon. TCPA 15 min CPA 0. 5 nm 16-3 AIS Windows To go to the AIS windows, press , select More, select AIS, then press or to select one of the two windows: Vessels or Safety msgs (rx). If there are more items than will fit on the window, press or to see the others. Vessels This is a sorted list of vessels currently being received by the AIS receiver. The maximum number of vessels that the system will support is 250. Once maximum is reached, vessels furthest away from the current location will be replaced. A vessel will be removed from the list if no information is received within 6 minutes from the last message. Displaying an AIS vessel on the chart 1 Press or to select a vessel. The Instrument switches to chart window, with the selected vessel position in the middle. 58 Northstar M121/M84 Installation and Operation Manual Displaying Full AIS Details 1 Press or to select a vessel. This window displays all information for the selected AIS vessel provided by the AIS receiver. Safety msgs (rx) Safety msgs (rx) are broadcasted messages received by the AIS receiver. This window displays the date and time of message received, MMSI of AIS vessel that broadcasted the message, and the message itself. [. . . ] The distance from the plotted course to a CDI line is the CDI scale. Set the CDI scale (see section 17-2) to the maximum distance that the boat should deviate from the plotted course. The chart and highway windows show the CDI lines, which are like a highway over the water where the boat will move. The windows show how far the boat has deviated from the plotted course and if the boat is approaching a CDI line. [. . . ]