User`s guide

156 Agilent 34980A Mainframe User’s Guide
3 Features and Functions
To Change the Security Code
To change the security code, you must first unsecure the instrument, 
and then enter a new code. You can change the security code from the
remote interface only. Make sure you have read the security code rules
described on page 155 before attempting to change the security code.
Remote Interface Operation: To change the security code, unsecure the
instrument using the old security code. Then enter the new code as
shown below. 
Calibration Count
You can query the instrument to determine how many calibrations have
been performed on the entire mainframe, the digital modules, or the
internal DMM (remote interface operation only). Note that your
instrument was calibrated before it left the factory. When you receive 
your instrument, be sure to read the various counts to determine the
initial values.
• The calibration count is stored in non- volatile memory in the
mainframe, and does not change when power has been off, after a
Factory Reset (
*RST command), or after an Instrument Preset
(
SYSTem:PRESet command).
• The calibration counts increments up to a maximum of 4,294,967,295
after which they roll over to “0”. Since the value increments by one for
each calibration point, a complete calibration may increase the value by
many counts.
• The calibration count is also incremented with calibrations of DAC
channels on the 34951A Isolated DAC Module and 34952A Multifunction
Module.
Remote Interface Operation: CALibration:COUNt?
CAL:SECURE:STATE OFF,AT34980
CAL:SECURE:CODE SN123456789
Unsecure with old code 
Enter new code