Connecting your TNC

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You can connect your TNC to any port that is capable of supporting interrupt handling.This means the port must have a unique IRQ. In most PCs, COM 1 and 2 will work fine, but often the  COM3 and/or COM 4 ports, if fitted either do not have, or share an IRQ line. Such ports cannot be used for the TNC interface, but could be used for the Morse code keyer output, for example.


Your TNC to computer cable should be a straight though type, without crossover of the TxD and RxD lines, as shown in the example for connecting your transceiver. Please note, however, as a net result TxD and RxD need to be crossed. This is performed in most cases by the interface unit. If hardware handshake is to be activated by connecting RTS and CTS on both sides (TNC and PC) these wires need to be crossed as least as a net result with respect to the interface unit.


This means: An output/transmitting pin on one side of the serial interface must always see an input/receiving pin on the other side. The wiring has to be performed accordingly.


This topic was last edited on  Thursday, 17-Jun-2021,  at  10:49