‘Iable 12-1 shows the memory requirements of calibration arrays and memory trace arrays to help you approximate memory requirements. For example, add the following memory requirements:

na full 2-port calibration with 801 points (58 k)

nthe memory trace array (4.9 k)

nthe instrument state (approximately 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:

na full 2-port calibration with 1601 points, two channels, uncoupled (230 k)

nthe memory trace array (19 k)

nthe instrument state (approximately 6 k)

only 2 of these calibrations could reside in memory before the available memory would be depleted.

‘lhble 12-1.

Memory Requirements of Calibration and Memory Trace Arrays

Variable

 

 

Approximate lbtds (Bytes)

 

 

 

m

 

 

 

 

 

 

 

(Alaration Arrays

 

 

 

 

 

 

F&?SpOIlSt2

Nx6+62

2.6k

6k

10 k

19 k

Response and isolation

Nx6x2+62

6k

10 k

19 k

38 k

l-Port

Nx6x3+62

7k

14k

29k

68k

a-port

Nx6x12+62

29 k

68 k

116 k

230 k

Interpolated Cal

Same as above in addition to regular cal

 

 

 

 

 

 

 

 

 

Power Meter CM’

(Nt x 2 x number of channel& +208

 

 

 

 

 

 

 

 

 

 

 

Mea8Mement Data

 

 

 

 

 

 

Memory trace array*

Nx6+62

 

 

 

 

Instnmlent state’

N - number of pointa

- This variable is allocated once per active channel.

t The number of points that was set at the time the cal was turned on.

$ If the channels are coupled, this number is always 1. If the channels are uncoupled, this number refers to the number of channels that have power meter cal on.

# This value may change with diKerent firmware revisions.

The analyzer attempts to allocate memory at the start of a calibration. If insufficient memory is available, an error message is displayed. It is possible that the CMOS memory might be fragmented due to the sequence of saving and deleting states of various sizes. So another alternative would be to store the current state to disk and then press Ipresetl. The anaIyzer runs a memory packer which might regain some previously inaccessible memory. If memory is still inadequate, delete an instrument state and restart the calibration.

Preset State and Memory Allocation 12-3