Xylem SDI-12 Data Logger iLink - Manual (Page 65)

iLink Configuration and Support Utility 65
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APPENDIX C
DS-4483 Lookup Tables
The DS-4483 supports a single lookup table for use in calculating derived data from an attached sensor.
This format is identical to that used by HydroTel 2000™.
The lookup table must be contained in a text file with a .tbl extension and only integer values are
permitted. The format of the table is that of ‘paired couplets’. An excerpt of a sample table is shown
below:
1000 Recorded value from attached physical sensor
21600 Value to be inserted for derived sensor
1010 Recorded value from attached physical sensor
22000 Value to be inserted for derived sensor
1020
22300
1030
22600
1040
22900
1050
23200
1060
23600
The DS-4483 deals with recorded values that fall between table entries by using simple linear
interpolation. Thus for the table above, if a value of 1005 is recorded, the associated derived value will be
calculated as:
21600
+ (22000 – 21600) * (1005 – 1000) = 21800
(1010 – 1000)
Table Size
The DS-4483 will support tables ranging from 2 couplets up to 512 couplets.