88 34405A User’s and Service Guide
4 Performance Tests and Calibration
Unsecuring the Instrument for Calibration
Before you can adjust the instrument, you must unsecure it
by entering the correct security code. The security code is
set to AT34405 when the instrument is shipped from the
factory. The security code is stored in non- volatile memory,
and does not change when power has been off or after a
Factory Reset (*RST command).
Unsecuring from the Front Panel
Only five characters (the third through seventh characters)
of the security code are used to unsecure the instrument
from the front panel. If there are letters instead of digits in
any of the third through seventh characters, those letters
will be represented as "0" from the front panel.
Example 1
Assume the calibration security code is the factory setting of
AT34405. When unsecuring from the front panel, the code
length is five characters and the first two characters are
ignored. In our example, the code now becomes:
34405
Example 2
Assume the calibration security code was set to AT01A405
from the remote interface. When unsecuring from the front
panel, the first two characters and any characters after the
eighth through twelfth character are ignored. In our
example, the code now becomes:
01A40
From the front panel, any letters (A in this example) are
represented by 0. Use this code to unsecure:
01040
34405A users guide.book Page 88 Saturday, September 2, 2006 3:38 PM