Setting up a Serial TNC

This interface type is for standard converse-mode TNCs on serial ports.

Important

A common mistake is to try to use this interface type to attach a serial KISS TNC to Xastir. The interface types are different. If you have a serial KISS TNC you're on the wrong page.

• Activate on startup?: Select this if you want Xastir to connect to this TNC every time it starts.

• Allow Transmitting?: If unchecked, Xastir will never send data to this interface, only receive.

• Add delay: Causes Xastir to pause for one second between sending the Converse command and any subsequent commands. This feature exists entirely to deal with ancient Kantronics KAM TNCS that sometimes failed to go into converse mode if you immediately sent more data after it. Don't set this unless you have one of those.

• TNC port: The name of the serial port to which the TNC is connected.

• Converse command: TNCs of this type typically want either "conv" or "k" here. Consult your TNC's user manual.

• Comment: A note to yourself. This shows up in the Interface Control dialog in the list of defined interfaces.

• Port Settings: You set the baud rate of the serial port and TNC here. NOTE: This is NOT the baud rate of the TNC on RF! It's the speed at which the computer communicates with the TNC.

• Port style: Set the number of bits, parity, and stop bits here.

• IGate Options: Will we forward traffic from this port to and/or from internet servers? (Don't enable igate features unless your local environment really needs more internet/rf gateways!)

• UnProto Paths: Select the paths your packets will take. Xastir will cycle between paths 1,2, and 3 each time it transmits one of your posits. Please don't use paths with lots of hops. When in doubt, use "WIDE2-2" and leave it that way. We should find a good, readable source that explains this and link here.

• The "Igate->RF Path" is only used when gating internet packets to RF and is otherwise ignored.

• TNC Configuration Files: You need to put your TNC into the correct state to be used with Xastir. Xastir comes with a number of pre-rolled TNC startup and stop files. Find one that matches your TNC version and use it. If you have to craft a new one for some new TNC you'll have to consult the manual for your TNC and figure it out.

  Similarly, when Xastir exits it might need to take the TNC out of whatever state it was put in for APRS operation.

  Assuming we already have a TNC startup file for your TNC model, it'll be called "tnc-startup.<something>" in the Xastir config directory (/usr/local/share/xastir/config or /usr/share/xastir/config). Put this file name in the TNC Setup Filename box.