Specifications

TNC GPS Upgrade Addendum/
1111
1111
11
4. Apply power to the GPS receiver (NOT THE TNC YET).
5. Be sure that the GPS receiver is outputting its NMEA data before powering up the
TNC.
6. Power up the TNC and within 4 seconds, you should notice the TNC transmit LED
lighting to transmit its location.
GPSMode “n” Default: 0 Disabled
This is a variable ranging from 0-3 that selects a specific mode of operation specific to GPS.
Three CTRL-C’s returns unit to GPSMode 0.
Mode 0 = Normal Packet TNC operation. (GPS operation disabled.)
Mode 1 = TNC connected directly to a GPS receiver.
The TNC will begin parsing its programmed NMEA sentences under the following
conditions:
1. GLOCtx timer expires
2. The TNC receives an Unproto frame containing ?APRS?
3. The TNC receives an Unproto frame containing MYCALL..:?APRS?
4. The TNC receives an Unproto frame addressed to its POLLCALL
Upon reception of one of these types of frames, the TNC will begin to parse its programmed
NMEA sentences. If the TNC successfully parses one or both of its NMEA sentences, it will
transmit the information parsed as a single UI frame. If there is no data received from the GPS re-
ceiver within four seconds, it will reset its GLOCtx timer and continue.
Mode 2 = TNC connected directly to an ULTIMETER II.
The TNC will begin parsing its programmed NMEA sentences under the following
conditions:
1. GLOCtx timer expires
2. The TNC receives an Unproto frame containing ?WX?
3. The TNC receives an Unproto frame containing MYCALL..:?APRS?
4. The TNC receives an Unproto frame addressed to its POLLCALL
Upon reception of one of these types of frames, the TNC will begin to parse its programmed
NMEA sentences. If the TNC successfully parses one or both of its NMEA sentences, it will
transmit the information parsed as a single UI frame. If there is no data received from the GPS re-
ceiver within four seconds, it will reset its GLOCtx timer and continue.
GREMprog ON|OFF Default: OFF
ON - Remote programming is enabled in GPS mode.
OFF - Remote programming is disabled in GPS mode.
While operating in one of the GPS modes, the following commands can be programmed:
1. GLOCtx
2. GNMEA1
3. GNMEA2
4. GINIText