TAPR TNC-2 Release 1.1.9 Notes (c) 1994 InfoMotion, Inc. All rights reserved. Permission granted to TAPR, its TNC-2 OEM licensees, InfoMotion licensees, and all licensed radio amateurs, to reproduce the contents herein, provided this notice and the contents of this document are reproduced intact. General: The checksum for TAPR release 1.1.9 containing the KISS module is $2D. InfoMotion licensees will not receive the KISS module; the checksum will therefore be some value other than $2D. Release 1.1.9 incorporates these new features: o - CW identification in FSK using the onboard packet modem o - Enhanced monitor mode filtering o - Support for Dallas Semiconductor "Smartwatch" (tm) socket o - NMEA beaconing mode o - Modified P-Persistence And these changes: o - The pound sign ASCII character "#" is allowed in callsigns o - The "OUT" command installed in version 1.1.8 was removed o - In addition to identification at 9.5 minute intervals, The HID function transmits an identification packet upon incoming connect acknowledge, outgoing connect attempt success, disconnection, and cancellation of outgoing connect attempts. o - DWAIT is now applied to digipeated and non-digipeated packets o - Delay equivalent to the current DCD backoff time is applied after transmit release to prevent multiple transmissions with extremely small delays in between Corrections, bug reports, enhancement requests and the like should be directed by mail to: InfoMotion, Inc. 425 Seagrass Avenue Sebastian, Florida 32958 USA Internet: n2wx@tapr.org Compuserve:75006.702 Specifics --------- CW Ider Commands: CWId {ON/OFF} default: OFF FSK cw identification is now available. When CWID is ON, the string in the IDTEXT parameter is send at 20 WPM in international morse code at the times described for the HID command. If text is not present in the IDTEXT parameter, no code will be sent. The feature will not send correct code if the on-board NRZ->NRZI converter is bypassed. When using the CW IDer, the HID function (HDLC identification) must be set to OFF or CW identifier may not automatically be transmitted at the 9 1/2 minute interval. A CW ID also occurs on connection activation, outgiong connect attempt success, upon a complete disconnect or when the disconnect is forced. Because current regulations do not require a morse identifier within the United States, users are requested to leave CWID set to the defaulted OFF position lest they burden the channel with unecessary identification. Monitor filtering MNONPrin {ON/OFF} default: ON The TNC will examine the contents of each monitored packet for nonprinting ASCII characters and discard the entire packet if at least one is detected. Nonprinting characters means any ASCII character less than the space character except for BELL, LF, and CR, and the DEL character. The test occurs after masking off the high order bit. By setting MNONPRIN to OFF, and in concert with MNONAX25 OFF, the TNC will filter nearly all screen-garbage inducing monitored packets. NMEA beacon function TNC-2 now incorporates a dedicated mode enabling the broadcast of one or two NMEA version 2.00 (and compatible) sentences to the UNPROTO address. When placed in NMEA mode with a non-zero value in the NMEABCN parameter, the TNC broadcasts the most recently received sentences received from the attached NMEA talker on the radio link. No other outgoing transmissions are permitted with the exception of identification, beacon, CTEXT, and mailbox data (*if supported). NMEA devices provide an ASCII output at 4800 baud, 8/N/1, consisting of one or more types of sentences containing various types of data. Most commonly these data contain navigation fixes. For example, the author's global positioning system receiver (Garmin model GPS-55AVD) generates sentences containing the receiver's longitude and latitude (fix), time of the fix, groundspeed, waypoint data, and the like. An example: $GPRMC,034523,Y,02754.31,N,08023.03,W,1.5,035,031294,4,W*23 Meaning: "$GPRMC" - Indicates the type of data (RMC-minimum recommended GPS sentence) 034523 - UTC hh/mm/ss Y - data valid 02754.31,N - longitude 08023.03,W - latitude 1.5 - groundpseed 035 - Track made good over the ground (degrees true) 031294 - date ddmmyy 4,W - magnetic variation, West 23 - checksum (ignored by the TNC) (Note that this example sentence was not actually generated by the unit and the checksum is probably wrong) The TNC automatically ignores the linefeed character - it will not be broadcast. Please note that the sentences are sent in the non-protocol mode, thus there is a distinct possiblity that the intended recipient may not receive the broadcast. Users desiring a gauranteed link should NOT use this new mode and should continue to utilize the TNC in connected mode. ** IMPORTANT ** TNC-2 firmware is provided "AS-IS" AND THE USER ASSUMES THE ENTIRE RISK OF UTILIZING THE FIRMWARE. TNC-2 FIRMWARE IS NOT INTENDED NOR IS IT PROVIDED FOR ANY PURPOSE, INCLUDING NAVIGATION, WHEN FAILURE OF THE FIRMWARE, OR HARDWARE, OR BOTH, MIGHT CAUSE BODILY INJURY OR LOSS OF PROPERTY. NEW COMMANDS ------------ NMeabcn 0..254 default: 0 The NMEABCN parameter defines the 10-second interval between broadcasts of the one or two most recently received NMEA sentences to the UNPROTO address =. If none of the selected sentences (see NMEAFLT1 and NMEAFLT2 for information regarding the selection) were received since the last power on, no broadcast is made. Normal TNC operation is enabled when the parameter is 0. NMEA mode is enabled when a non-zero value is present, and the TNC powers up in the selected CONMODE. CONMODE *must* be set to CONVERSE, SENDPAC to $0d, and CR set ON (all defaults) for the NMEA parsing to work correctly. NMEAFLT1 sssss default: empty NMEAFLT2 sssss The "sssss" is the 5 character NMEA preamble defining the device and sentence types. The parameter must be coded exclusive of the leading "$" character. Ex: User desires to broadcast the GPS fix and UTC sentences produced by a GPS board cmd:NMEAFLT1 GPGGA NMEAFLT1 was cmd:NMEAFLT2 GPZDA NMEAFLT2 was cmd: Ex2: User now only wishes to broadcast wind vector data from a weather station cmd:NMEAFLT1 WIMWV NMEAFLT1 was GPGGA cmd:NMEAFLT2 % NMEAFLT2 was GPZDA cmd: NMEA NOTES: o - To enable NMEA compatability, the TNC should be configured for 4800 baud, 8 bit, no parity operation. o - NMEA defines a balanced RS-422 interface. A particular NMEA device may or may not function with the TNC-2's RS-232 interface. In the perfect world, everyone would attach the devices with an RS-422<>RS-232 converter, and the author recommends that one be used. THE USER THEREFORE ASSUMES THE ENTIRE RISK OF ATTACHING THE RS-422 NMEA DEVICE TO THE TNC-2 RS-232 PORT, including permanent damage to the NMEA device, or the TNC, or both. *-*-* Modified P-Persistance P-persistance is a channel sharing technique that has gained great favor in the TCP/IP world. A modified form of P-persistance is now included in TAPR TNC-2 as an alternative to prioritized acknowledgements and DWAIT. Modified P-persistance relies on two principles to achieve a more equitable sharing of the common frequency. First, when the TNC waits a random multiple of DWAIT after hearing another station before it transmits. The upper limit of the random value is user defined by the PERSIST parameter to prevent frequency monopolization by stations placing unusually heavy demands on the frequency, as with the case of a file transfer. Modified P-persistance increases the likelihood that a station with higher priority traffic can acquire the channel. The second way modified P-persistance promotes channel sharing is by gradually increasing the wait time when the TNC executes retry transmissions. Modified P-persistance as implemented in TNC-2 differs from standard P-persistance in that acknowledged retries do not cause the time delays to cumulate. After a retry is successfully acknowledged the TNC reverts to the shorter delay that assumes a perfect channel. Another difference is that the retry delay is applied only to connections on stream A. Modified P-persistance is selected by setting PPERSIST to ON and ACKPRIOR to OFF. NEW COMMANDS: ------------ PERSIST 0..254 default: 8 Defines the persistance, or delay, the station tolerates. The actual delay is a random period of time between one DWAIT period and PERSIST DWAIT periods. The default value is appropriate for keyboard users and most digipeater installations. Higher values around 16 or 24 are appropriate for file transfers. PPERSIST ON/OFF default: OFF PPERSIST ON enables the P-persistant function described above. ACKPRIOR must be turned off for this feature to function. *-*-*