A great feature of TempTrax is its ease in user programmability. This is
especially important to those who don't wish to use our proprietary software
- they simply want to hook up TempTrax to the computer's serial port and
access the data via their own software calls to the unit. This can be
accomplished in any number of ways (including Excel, Visual Basic, Visual
C++, Perl, etc - ). As long as TempTrax is plugged into a PC compatible
serial port and you have access to the port, you can get the temperature.

Here's how to retrieve the temperature from the Model B family. The serial
port needs to be setup in the following manner:

      9600 Baud
      No Parity
      8 Data Bits
      1 Stop Bit
      No Flow Control

After opening up the comport, send any character out the computer's serial
port. This will "wake up" the TempTrax and it'll take a measurement and
respond with an ASCII string of data that will look something like the
following:

      76.8
      34.5
      Bat Ok

The 1st line returned is the temperature in °F of probe #1, the 2nd of probe
#2, and the 3rd line gives the battery conditions. You will need to wait
about a second before looking for the returned string.  And that's it!

TempTrax draws very little current and consumes most when being "talked"
to. Therefore, the more it is interrogated, the shorter the battery
life. However, interrogation of every minute should give at least a couple
of years battery life (the unit uses to very common coin cells, CR2032) - so
less frequency would give even longer life.

Only 3 serial port lines are used with the TempTrax Model B family -
Transmit, Receive and Ground.

Here's how to retrieve the temperature from the Model F family. The Model F
family differs from the Model B in that the Model F family uses the DTR
signal (Pin 20 of the DB25 connector) as its power source. This has
significant value in that you never have to change or buy batteries. The
only drawback is that you have to manipulate that lead (set to logic "1")
before interrogating the TempTrax. The serial port needs to be setup in the
following manner:

      9600 Baud
      No Parity
      8 Data Bits
      1 Stop Bit
      No Flow Control
      DTR On (Logic "1" or high)

After opening up the comport and setting DTR high, send any character out
the computer's serial port.  This will "wake up" the TempTrax and it'll take
a measurement and respond with an ASCII string of data that will look
something like the following:

      76.8
      34.5
      Bat Ok

The 1st line returned is the temperature in °F of probe #1, the 2nd of probe
#2, and the 3rd line gives the battery conditions. You will need to wait
about a second before looking for the returned string.  And that's it!

Only 4 serial port lines are used with the TempTrax Model F family -
Transmit, Receive, DTR, and Ground.

Note that the only difference between interrogating the Model B family and
the Model F family is that you have to set the DTR line of the Model F
TempTrax to a logic high level.