HP 8753E manual Non-Volatile Memory

Non-Volatile Memory

This is CMOS read/write memory that is protected by a battery to provide storage of data when line power to the instrument is turned off. With this battery protection, data can be retained in memory for ~250 days at 70’ C and for ~~10 years at 25” C (characteristically).

Non-volatile memory consists of a block of user-allocated memory and a block of fixed memory. The user-allocated memory is available for you to save the following data:

ninstrument states

nmeasurement calibration data

npower meter calibration data

nuser calibration kit definitions

nmemory traces

nuser preset

Note Even though calibration data is stored in non-volatile memory, if the associated instrument state is not saved, you will not be able to retrieve the calibration data after a power cycle.

The fixed memory is used to store the following data (you cannot change where this data is stored and it does not affect your memory availability for storing user-allocated data):

nHP-IB addresses

ncopy configuration (printer and plotter type, port, baud rate, handshake)

npower meter type (HP 436/438)

ndisplay colors

nsequence titles

nsixth sequence

npower sensor calibration factors and loss tables

nuser-deflned calibration kits

nsystem ZO

nfactory preset

nHP-IB configuration

ndisplay intensity default

The maximum number of instrument states, calibrations, and memory traces that can reside in non-volatile memory at any one time is limited to 31 instrtmient states, 128 calibrations (4 per instrument state, including the present instrument state), and 64 memory traces (4 per instrument state, including the present instrument state).

In addition, the number of instrument states and associated calibrations and memory traces are

limited by the available memory. lb display the amount of unused memory on the analyzer, ,. ,. ,....,.,.,.; _; _ .,

press (jj). (Be sure you have selected ~~~~.~~~~ as your disk type.) In the
:t<_........ :<~.:.:..:.::.-	~:..:::::	:~...~.~.~.~.~.~.~.~.~.~.~
upper right-hand portion of the display, the value	displayed as Bytes free : is the unused

non-volatile memory. When you save to the internal memory, you will see the number of bytes free decrease. When you delete ties, the number of bytes free increases. There is a maximum of 2 MBytes available.

If you have deleted registers since the last time the instrument was preset, the bytes available for you to use may be less than the actual “bytes free” that is displayed. Deleting registers to increase the available memory will work in cases where the registers being deleted and the registers needing to be added are of the same standard size (such as instrument states not having calibrations associated with them). In certain other cases, however, you may have to press m after deleting registers so that the “bytes free” value equals the available memory value. During a preset, the analyzer runs a memory packer that de-fragments the free memory into one contiguous block.

12-2 Preeet State and Memory Allocation