Racal Instruments 1256 Manual page 62

Publication No. 980855 Rev. A
EADS North America Test and Services
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Updating Non-Volatile RAM
Non-volatile (flash) RAM is inherently slow. If presets were stored
directly in non-volatile RAM, the user would have to wait several
seconds for each store operation. This may not always be an
inconvenience when working with the front-panel controls, but would
certainly slow down software that automatically sets up and stores
many presets.
To avoid the delay after storing each preset, the presets are written
to a temporary area of the static random-access memory (SRAM).
This memory is volatile (will erase upon power-down), but is very
fast. This allows presets to be stored rapidly. Once the last desired
preset has been stored, the presets stored in SRAM (known as the
SRAM image) may be written to non-volatile RAM all at once. Since
the non-volatile RAM is block-oriented, it takes the same amount of
time to write many presets as to write just one. Thus, by writing all of
the desired presets to non-volatile RAM just once, much time is
saved.
To update the non-volatile RAM with the SRAM image, follow these
steps:
1. Press the top key next to the display. Rotate the knob until the
top line reads:
>---STORE/RECALL---<
2. Select line 2 (next to the top line) by pressing the second key.
Rotate the knob until line 2 of the display reads as follows:
---STORE/RECALL---
> Type: NVRAM
Config: Image
Status: Erase
3. Press the fourth key to select line 4 of the display. Rotate the
knob until line 4 reads:
---STORE/RECALL---
Type: NVRAM
Option: Image
< Do?: Update
4. Press the fourth key (bottom) to store the power-up state.
Pressing any other key cancels the change.
Erasing Non-Volatile RAM
The entire non-volatile RAM may be erased if desired. This erases
all presets, including switching states, the power-up switching state,
and the menu preferences. The menu preferences will be set to the
factory defaults.
1256 User Manual
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Using the Front-Panel Controls 3-27