Laurel Electronics LTM CTR SERIES PULSE, AC or PROCESS TOTALIZER INPUT, SERIAL DATA OUTPUT - Manual (Page 27)

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Calibration of the quartz crystal is easily accomplished using Instrument Setup software. Select
Calibration from the Main Menu. Apply a frequency reference signal, and enter the known
frequency in Hz. Calibration of the V-to-F signal conditioner requires use of voltage reference
signals and the calibration program vfcal3.exe, which is available for download.
16. CUSTOM CURVE LINEARIZATION
Curve.exe is a DOS-based, executable PC program used to set up an Extended transmitter so
that the analog output and internal digital readings have a user-defined, non-linear relationship
with the input signal. The calculated linearizing parameters are downloaded into non-volatile
memory of the transmitter. The curve-fitting algorithm uses quadratic segments of varying
length and curvature, and includes diagnostics to estimate curve fitting errors. The program is
self-prompting, avoiding the need for detailed printed instructions. This manual section is only
intended as an introduction.
GETTING STARTED
Download curve.exe from the distribution CD into the same directory that will contain your
data files, such as c:\curves. Connect your transmitter to the PC and double-click on curve.exe,
which is an executable file. Follow the steps on the computer screens, which will prompt you
and provide extensive help information. Pressing R (Enter) returns to the main menu. You will
be given the choice of four data entry modes, all of which are explained in detail.
1) Text file entry mode,
2) 2-coordinate keyboard entry mode,
3) 2-coordinate file entry mode, and
4) Equation entry mode.