User`s manual

Manual revision 016 Section 4: Deploying and Operating FastCAT SBE 49
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Data Output Formats
Output format is dependent on OutputFormat (=0, 1, 2, or 3). Each line of
data is ended with a carriage return and line feed.
OutputFormat=0 (raw data in Hexadecimal)
Data is output in the order listed, with no spaces or commas between
parameters. Shown with each parameter is the number of digits, and how to
calculate the parameter from the data (use the decimal equivalent of the hex
data in the equations).
1. Temperature A/D counts = tttttt
2. Conductivity frequency (Hz) = cccccc / 256
3. Pressure sensor pressure A/D counts = pppppp
4. Pressure sensor temperature compensation voltage = vvvv / 13,107
OutputFormat=1 (engineering units in Hexadecimal)
Data is output in the order listed, with no spaces or commas between the
parameters. Shown with each parameter is the number of digits, and how to
calculate the parameter from the data (use the decimal equivalent of the
hexadecimal data in the equations).
Note that if ProcessRealTime=Y, the output data has been aligned, filtered,
and corrected for cell thermal mass effects.
1. Temperature (°C, ITS-90) = (tttttt / 100,000) - 10
2. Conductivity (S/m) = (cccccc / 1,000,000) - 1
3. Pressure (decibars) = (pppppp / 1,000) - 100
Example: example scan = ttttttccccccppppppvvvv = 0A53711BC7220C14C17D82
• Temperature = tttttt = 0A5371 (676721 decimal);
temperature A/D counts = 676721
• Conductivity = cccccc = 1BC722 (1820450 decimal);
conductivity frequency = 1820450 / 256 = 7111.133 Hz
• Pressure = pppppp = 0C14C1 (791745 decimal);
pressure A/D counts = 791745
• Pressure temperature compensation =
vvvv = 7D82 (32,130 decimal);
pressure temperature = 32,130 / 13,107 = 2.4514 volts
Example: example scan = ttttttccccccpppppp = 3385C40F42FE0186DE
• Temperature = tttttt = 3385C4 (3376580 decimal);
temperature (°C, ITS-90) = (3376580 / 100,000) - 10 = 23.7658
• Conductivity = cccccc = 0F42FE (1000190 decimal);
conductivity (S/m) = (1000190 / 1,000,000) - 1 = 0.00019
• Pressure = pppppp = 0186DE (100062 decimal);
pressure (decibars) = (100062 / 1,000) - 100 = 0.062
Notes:
• If you will be using Seasave to
acquire real-time data, set
OutputFormat=0.
• For real-time data processing, set
OutputFormat=1 or 3 and
ProcessRealTime=Y.
• Our software uses the equations
shown to perform these calculations;
alternatively, use the equations to
develop your own processing
software. After the data is converted
to A/D counts, frequencies, and
volts, our software uses the sensor
calibration coefficients and the
equations on the sensor calibration
sheets to convert to engineering
units.
• The FastCAT’s pressure sensor is
an absolute sensor, so its raw
output includes the effect of
atmospheric pressure (14.7 psi).
As shown on the Calibration Sheet,
Sea-Bird’s calibration (and resulting
calibration coefficients) is in terms of
psia. However, when outputting
pressure in engineering units, the
FastCAT outputs pressure relative to
the ocean surface (i.e., at the
surface the output pressure is
0 decibars). The FastCAT uses the
following equation to convert psia to
decibars:
Pressure (db) =
[pressure (psia) - 14.7] * 0.689476
Note:
See Baud, Cable Length, and Data
Transmission Rate for the interaction
of output format, data transmission
rate, baud rate, and cable length.