Innovate Motorsports LogWorks 3 - Manual (Page 33)

LogWorks3_Manual_1.01.doc - 33 -
measurement sensor. This should NOT be used with devices with differential inputs like
LMA-3, SSI-4 and/or DL-32. They automatically compensate for ground differences when
connecting the CHx- input to the sensor’s ground.
The following is an example of an input lookup table:
PSI Volt
-14.7 0.1
-10.0 1.2
0 2.1
5 2.8
15 4
29.4 4.9
A DIF file must be organized similarly. The top left entry in the spreadsheet (field A1) must
contain the measured unit. The second entry (field B1) MUST contain the word “Volt”. The rest of
the ‘A’ column contains the measured quantity equivalents and the rest of the ‘B’ column contains
the equivalent voltages.
When loading the table LogWorks sorts it in ascending order by voltage. LogWorks then creates
a custom lookup table for all 1024 possible input values by interpolating between table points
using what’s called cubic splines (Not the right place here to explain what they are). The table
must be monotone rising or falling. If the difference between the second quantity and the first
quantity is positive, the quantities must be always rising (third bigger than second and so on. If
the difference is negative, the quantities must be always falling (third smaller than second and so
on). If this were not the case, the same voltage could mean different measured quantities.
Example of monotone lookup table (x in PSI, y in Volt):
0
1
2
3
4
5
6
-20 -10 0 10 20 30 40