The class B transmitter, as you know, is a “light” version of the class A transmitter. The differences are:Class B: lower rate of telegrams (e.g. every 30s for a speed of 14kn, whereas for the class A transmitter it is every 10s). Does not transmit the IMO number or the call sign. Does not transmit ETA ordestination. Does not transmit the status of navigation. It is necessary to receive or transmit binary messages. Does not transmit if the the ship is turning. Does not transmit the draft.
FAQ: easyAIS 2nd. Gen. >>>
It is possible with a special telegram.
The Message 22 by the class B AIS can stop temporally the transmitting a base station of a coast radio station. (It also can switch the transmitting telegram from all 30s to f.e. every 60min or even longer, if needed). The class A transceiver on the ships can not do that. Class A sender can not manipulate a class B sender. But there are difference ECDIS-electronic chart display information systems (norm EN61174) on the commercial shipments which does join with the class A AIS by it can inhibit the class b sender via filter function on the ECDIS display
The basic question is, whether the Powerbook has a serial COM interface (RS 232).
Some laptops do not have it. You can help yourself with a USB-to-COM adapter (which can be bought at e.g. Conrad, Media Markt, Saturn etc.).
The Apple or PC software (e.g. a terminal program) uses this COM interface and shows the encoded telegrams (ship reporting etc.), which have been received by the easyAIS. As the easyAIS works according to the NMEA0183 standard, the information is received as ASCII-telegram at 38400 baud (start and stop bit, no parity). Every common terminal program – no matter on which PC or Apple – can display these characters. In order to decode the AIS information you need a special software (e.g. a card plotter program with AIS functionality).
You can find a PC software on www.yacht-ais.de. Unfortunately, we cannot say whether it works with Apple or not.
