4.6 CALIBRATION MODE EXIT
The
Calibration Mode can be exited back to the Normal
Mode
via
the
Cal/Normal
Switch at
any time
except
for when
default
calibration data is being loaded.
In this case the
Calibration
Mode is exited when the loading of default data is complete.
When
the Calibration
Mode is
exited
the
instrument
will
initialize for the Normal Mode based on the current state of
the
controls,
as in the power up initialization.
4.7 CALIBRATION DATA STORAGE AND VALIDATION
All calibration data or other data which must be
retained
when
the
instrument
is turned off is stored in
EEPROM.
This data
consists of the following:
-
Transducer SPL calibration data by transducer and
frequency
-
Custom RTL values by transducer type
-
Custom RTL vs.
GSI RTL calibration selection
-
Attenuator
2.5V
maximum output level limit by stimulus
-
EEPROM checksum
The data is stored using a triple redundancy method (the same as
in the GSI 16 and GSI
33
control Processor).
In this method each
data bit is stored
3
times, once in each of
3
different blocks
within
the
EEPROM with a different format in
each of
the
3
blocks. When
a specific data bit is required
the
appropriate
location
in each of the
3
blocks is read and decoded.
For
the
data
to be valid the value from 2 of the
3
blocks
must
match.
This
method will allow for the detection of data errors and
the
correction of some errors.
If a calibration data read error is detected the frequency which
would use the data will not be available for testing in the
Normal Mode by forcing the stimulus off and not processing
operations
of the present bar.
The instrument will continue to
function and all other frequencies for which no calibration data
error
exists will be available.
A data error will be
indicated
by displaying the word
"CAL""
on the HL display until the
frequency or transducer is changed to a new selection that has no
data error.
In
addition to
the
triple redundancy validation
used
for
individual pieces of data,
a 2 byte checksum will be
stored in
the
EEPROM which will allow the validity of all data
stored in
the
EEPROM to be determined.
This check will be performed
when
the Calibration Mode is entered.
24
To Next Page
Loading...
