Anritsu ML2437A - Chapter 3: Memory and Security Considerations; Introduction; Secure Mode

ML2437A/38A OM/PM PN: 10585-00001 Rev. P 3-1
Chapter 3 — Memory and Security
Considerations
3-1 Introduction
The ML2437A/38A Power Meters have three different types of memory devices:
Internal Flash Memory (8 MB EEPROM)
This memory space is used to store the instrument firmware for the main processor and DSP
factory calibration. Also stored in this memory is the model number and serial number.
During a firmware update, the old firmware is erased. The firmware does not contain any
user information or any variables generated during the execution of the code. The internal
flash memory is not user accessible.
RAM Memory used by the DSP microcomputer (640 KB)
This is volatile memory used to store many parameters needed for the normal operation of the
instrument along with current measurement data. It is initialized on power up and is
completely cleared when powered down. This memory is not user accessible.
RAM Memory as non-volatile RAM (1 MB)
Non-volatile memory is used to store many parameters such as the current instrument setup,
saved instrument setups, offset tables, calibration adjustment values, user-set parameters,
etc. The user cannot write to this memory directly, but can store and retrieve instrument
set-up parameters in this memory. It can be cleared by an instrument reset operation (see
below).
3-2 Secure Mode
Information such as the cal factor frequency needs to be removed from the power meter if the
power meter is moved out of a secure environment. This can be accomplished by using the
secure mode to completely wipe the non-volatile static RAM of all information.
The user sets the secure mode on the power meter. When the power meter is next turned on
the non-volatile static RAM is completely purged of all information. The power meter then
sets the factory defaults for the current settings. To set Secure mode on, use the following key
sequence:
System | Secure | ON
Secure mode can also be enabled via the SECURE GPIB command (refer to “SECURE (Secure
system state) ” on page 8-68.
To manually reset the status to factory default, use the factory reset button described below.