The temperature measurement system is an expensive technique for monitoring temperatures at a remote location using packet radio.
A typical packet station configuration consists of a radio, TNC and terminal. When a distant station connects, the terminal comes alive with a screen message;
CONNECTED TO WB2K
If you are at the terminal, you note the message, and begin typing to WB2K.
Now, consider, if the terminal is replaced with the temperature measurment kit.
Upon receipt of the CONNECTED TO WB2K, the start bit of the first character initiates a measurement sequence.
The temperature processor then makes the measurements and sends the data to the TNC, just as you would type from a terminal.
Assuming the temperature system is configured in the multi-line format, the returned data might look like this;
0 5.23 1 13.62 2 28.65 3 -99.99 4 -99.99 5 -99.99 6 -99.99 7 -99.99
If you are interested in a customized "welcome message" or "closing message", please contact me.
For example;
Welcome to KZ3K's Remote Temperature Monitoring Station. The station is located in Bel Air, MD (Grid Square FM19). Rig is 1.5W to Groundplane at 350 feet above sea level. All temperatures are in degrees C. Channel 0 - Outside Temperature Channel 1 - Inside Temperature Channel 2 - Radiator Temperature Other channels are not used. 0 5.23 1 13.62 2 28.65 3 -99.99 4 -99.99 5 -99.99 6 -99.99 7 -99.99 73 de KZ3K ctrl-c d
The welcome message and closing message are each limited to 512 bytes. The messages are burned into one time programmable ROM and cannot be changed.
Note that in the above example, the temperature measurement system forces the disconnect.
It is important to note that in this application, there is a danger that RF may couple into the twisted pairs connecting the thermal sensors to the processor and thus, the radiation should be isolated from the twisted pairs.
73 de KZ3K