Siggen Calibration File

The Zauto utility can read a calibration file containing information on the power level for each nominal setting of the signal generator. This provides an accurate calibration of an automatic signal generator that is controlled by IRIS.

For example, a requested value of -30 dBm may actually be -30.2 dBm.

The Zauto calibration display shows the nominal requested setting and the calibrated value (with a resolution of 0.1 dB).

You can create the calibration file through a calibration program or typed in an editor. The file is SIGGEN_CAL.DAT in the IRIS_CONFIG directory (for example, /etc/vaisala/irisrda).

The following is a partial example.

#
# First set the date of the calibration in the following format
# Note the D in Date is capitalized.

Date: 10:15:00 20 OCT 1995

#
# Next the signal generator ID string
#

ID: XX aaa_BBB-CCC

#
# Now include a table of the integer nominal siggen values
# followed by the calibrated value as a floating point value.
# Start with the largest value.
#

0 0.1
-1 -1.1
-2 -2.1
-3 -3.1
-4 -4.1
-5 -5.1
-6 -6.1
-7 -7.1
-8 -8.1
-9 -9.1
-10 -10.1
-11 -11.1
-12 -12.1
-13 -13.1
-14 -14.1
-15 -15.1
-16 -16.1
-17 -17.1
-18 -18.1
-19 -19.1
.
.
.

Siggen Data Handling

Only the 128 dB span immediately below the first entry in the file is used. All values outside this range and all missing values are treated as correctly calibrated.

If the file is missing, then all values are treated as correctly calibrated, and the ID string is set to No siggen file.

If the file exists, but does not contain an ID string, the ID string is set to No ID in file.

The ID and date are displayed in the Zcal utility.