This section describes the profiles of the various types of memory that are used in the MS20xxC VNA Master and the associated security issues that are related to those memory devices.
The MS20xxC has 1 GB of Flash non‑volatile memory, has EEPROM memory, and has sufficient DRAM volatile memory for normal operation. The instrument is supplied with a USB memory device that plugs into the USB Type A connector. The MS20xxC does not have a hard drive or any other type of volatile or non‑volatile memory.
The following sections describe how memory is used in the VNA Master and how it can be erased.
Internal Flash Memory
This memory space is used to store the instrument firmware and factory calibration, and can be used to store measurements and setups that are saved by the user.
Saved measurements and setups that are stored in the Flash memory are all deleted by the master reset process that is described in Section “MS20xxC Master Reset Instructions” on the following page.
Note
With Option 7 enabled, the user is not able to store any measurements or setups to this internal flash memory.
USB Memory Device
The USB memory device is not required for proper operation of the instrument. The instrument may be directed to store measurements and setups directly to the USB memory device, or you may transfer the contents of the internal flash memory into the USB memory device for storage or data transfer purposes. The device is removable and therefore does not pose a security risk because it can remain in a secured area, can be externally erased by a computer, or can be destroyed.
Note
With Option 7 enabled, the user does not have access to the internal flash memory and, therefore, cannot transfer any contents of the internal flash memory into the USB memory device.
RAM Memory
This is volatile memory that is used to store many parameters that are needed for the normal operation of the MS20xxC along with current measurements. This memory is reset whenever the instrument is restarted.
EEPROM
This memory holds information such as the model number, serial number, and calibration data for the instrument. Also stored here are the operating parameters, such as frequency range, that are set by the user. During the master reset process, all operating parameters that are stored in the EEPROM are set to standard factory default values.
MS20xxC Master Reset Instructions
1. Turn the MS202xC or MS203xC On.
2. Press the Shift key then the System (8) key.
3. Press the System Options soft key.
4. Press the Reset soft key.
5. Press the Master Reset soft key.
6. A dialog box is displayed on the instrument screen to warn that all settings will be returned to factory default values, and that all user files will be deleted.
7. Press the Enter key to complete the master reset, or press the Esc key to abort.
8. After several seconds (which can grow to several minutes if a very large number of measurements have been saved in the instrument), the instrument reboots.