Technical data

8-12
Preset State and Memory Allocation
Memory Allocation
• sequence titles
• sixth sequence
• power sensor calibration factors and loss tables
• user-defined calibration kits
• system Z0
• factory preset
• GPIB configuration
• display 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 instrument 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. To display the amount of unused memory on the analyzer, press Save/Recall. (Be
sure you have selected INTERNAL MEMORY, as your disk type.) In the 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 files, 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 Preset, 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.
Determining Memory Requirements
Table 8-5 shows the memory requirements of calibration arrays and memory trace arrays to help you
approximate memory requirements. For example, add the following memory requirements:
• a full 2-port calibration with 801 points (58 k)
• the memory trace array (4.9 k)
• the instrument state (6 k)
The total memory requirement is 68.9 kbytes. There is sufficient memory to store 29 calibrations of this
type. However, the same calibration performed with 1601 points and 2 channels uncoupled would require
255 k bytes:
• a full 2-port calibration with 1601 points, two channels, uncoupled (230 k)
• the memory trace array (19 k)
• the instrument state (6 k)
Only 2 of these calibrations could reside in memory before the available memory would be depleted.