Specifications

TNC GPS Upgrade Addendum/

6. Now type Beacon E 60, then press ENTER. This will cause your TNC to transmit its

beacon text every five minutes. APRS must see the beacon text containing the position in-

formation and a weather symbol character before it will display your weather information.

7. Now you need to program the GNMEA1 sentence to match the output of the

ULTIMETER II. Type GNMEA1 #, then press ENTER. This will cause the TNC to begin

parsing the ULTIMETER II data starting with the # digit. ( Note some ULTIMETER IIs

start their string with a # digit and some start their strings with a * digit. This value may

have to be changed to a * if it does not work upon installation.)

8. Type TBAUD 2400, then press ENTER. This sets the TNC serial baud rate to match the

output of the ULTIMETER II.

9. Now type RESTART, then press ENTER. This will cause the terminal baud rate to

change to 2400 baud matching the ULTIMETER II. Change your terminal baud rate to

2400 baud to match that of the TNC.

10. Now type GPSMode 2, then press ENTER. Now press ENTER again to enter the stand-

alone weather station mode. Now disconnect the serial cable and connect the ULTIMETER

II, and you are ready to transmit weather information in an APRS system.

TNC Commands

GENDchar “n” Default: $0D (CTRL-M)

The default GENDchar of $0D requires the string to end with a CR,LF to conform with the

NMEA format. If this is changed, the sentence will end with whatever character is programmed.

This command does not need to be programmed for use with GPS or Loran devices. It is intended

for use with other formats.

GINIText text Default: None

text- Any combination of characters up to a maximum length of 60 characters.

This text will be sent to the serial port when the TNC is powered up with GPSMode NOT equal to

zero. This text is intended for an initialization string for OEM GPS cards requiring setup after

power-down. If not programmed, the TNC will send nothing at power-up.

FIGURE 5: Ultimeter II junction box pin assignments (Same for all Timewave TNCs)