Agilent Technologies L4400 manual Calibration Security, Following the procedure below

AL4451A and L4452A Calibration Procedures

Calibration Security

This feature allows you to enter a security code to prevent accidental or unauthorized adjustments of the instruments. When you first receive your instrument, it is secured. Before you can adjust the instrument, you must unsecure it by entering the correct security code.

N O TE	If you forget your security code, you can disable the security feature by
	following the procedure below.

•Calibration is secured and unsecured using the command:

CALibration:SECure:STATe <mode>,<code>

•The security code is set to ATL4400 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, after a Factory Reset (*RST command), or after an Instrument Preset (SYSTem:PRESet command).

•The security code may contain up to 12 alphanumeric characters. The first character must be a letter, but the remaining characters can be letters, numbers, or an underscore ( _ ). You do not have to use all 12 characters but the first character must always be a letter.

•The L4451A 4- Channel DAC has two modes of adjustment, based upon the setting of the calibration security feature. Additional details are described in “L4451A 4- Channel Isolated DAC Module" on page 253.

Refer to the Programmer's Reference Help File located on the Agilent L4400 Product Reference CD- ROM for complete information on the L4451A and L4452A calibration command.

To Unsecure the Instrument Without the Security Code To unsecure the instrument and reset the security code when the current security code is unknown, follow the steps below.

1Turn off power to the instrument.

2Remove the instrument sub- assembly from the instrument carrier.

3Turn on the instrument (carrier).

4Send the command CALibration:SECure:STATe OFF,<code> to the instrument. Enter ANY valid (see above) code. This code is temporarily used to unsecure the instrument.

5Send the command CALibration:SECure:CODE <new_code> and enter the instrument’s new security code. Record this code for future reference.

250 L4400 User’s Guide