The next section is the memory setup. In most applications, the memory is large enough
to hold several minutes of data. This allows the memory to be divided into several
"partitions" in order to store several runs. When a recording is initiated, the computer
will automatically store the data to the next available partition. If all partitions have been
used, the computer will clear the oldest recording and use that partition to record the data.
When you select the number of runs to store, the seconds per run will be calculated from
the sample rates you have selected and will be displayed in the seconds window. This
tells you how long the recording will be, so select the number of runs that will allow the
computer to store the complete run as well as some additional time. For example, if your
car runs 9.90, select the number of runs that allows for 20 or more seconds of recording.
The Acquisition Mode setting tells the data logger how to store the run. This can be
either Manual or Automatic. If Manual is selected, the computer will begin recording
when the record button is pressed and record until the memory partition is full, then stop.
This is ok in most cases, but can be frustrating if something delays the start of the run.
For example, if the unit is setup to record eight, twenty second runs, and the record
button is pressed before you stage, the recording starts at that time. Then if the racer in
the other lane doesn't stage until 10 seconds later, and the green comes 2 seconds after
that, you only have 8 seconds of recording time left. If you run 12.0, the last 4 seconds of
the run won't be stored.
The Auto mode allows the computer to watch for the start of the run and use the memory
efficiently, allowing the complete run to be stored regardless of how long it takes to start
the run.
By selecting one or more of the Auto settings and entering "launch values" in the ERPM,
DRPM and/or Accel windows, you are telling the computer how to detect the start of the
run. If one or more of the Auto setting is selected, the logger will be setup to record the
amount of time prior to launch that is selected in the "Seconds of prelaunch" window,
then fill the remaining memory during the run, then stop. (You will need an
accelerometer connected to the data logger for the Accel start function to work.)
For example, if Auto start is set for ERPM at 5000, and the unit is set for 8, 20 second
runs, with 3 seconds of prelaunch, the computer will begin recording when the record
button is pressed, and then watch for the engine RPM to exceed 5000. Once the RPM
goes over 5000 during staging or at launch, the computer will store the previous three
seconds of data, then record the run in the remaining memory.
This way, it doesn't matter how long the delay was from the time the record button was
pressed until the run started, the computer still stores the complete run. The only thing to
remember is that the computer will begin the main recording once the RPM level is
exceeded, so if you press record, then rev the motor to clear it, the main recording will be
started, so if you normally clear the motor prior to staging, don't press record until after
you clear the motor, or use the DRPM and/or Accel setting for the Auto start.
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