System overview
Output terminals
The TR-8000 Transponder box contains the terminals with the AIS serial output.
One of the two highlighted terminals can be used. Always make sure that the initially connected listeners receive the AIS signal.
In RS-485/RS-422, GND is not required; the signal is differential, and GND is not a reference point for that signal; hence, only TX-A and TX-B are highlighted.
Terminal | Name |
7 | TD2-A (-) |
9 | TD2-B (+) |
19 | TD4-A (-) |
21 | TD4-B (+) |
Parallel connection
The installation manual does not give full specifications about the output load. However, the IEC 61162-2 standard (Single talker and multiple listeners, high-speed transmission) says:
QUOTE
5.6.3 Listener receive circuits
Multiple listeners may be connected to a single talker. The listener's receive circuit shall comply with ITU-T Recommendation X.27/V.11. Optional termination resistors for the line shall be provided. The input terminals A, B and C shall be electrically isolated from the remaining electronics of the listening device. Reference is made to 5.6.4 and a sample circuit shown in Figure 1.
UNQUOTE
Therefore, if both ports are occupied, establish another parallel connection to one of the terminals. Always make sure that the initially connected listeners receive the AIS signal.