Using Memory Traces And Memory Math Functions - Agilent Technologies 8753ET User Manual

Using Memory Traces and Memory Math Functions

The analyzer has four available memory traces, one per channel. Memory traces are totally channel
dependent: channel 1 cannot access the channel 2 memory trace or vice versa. Memory traces can be saved
with instrument states: one memory trace can be saved per channel for each saved instrument state. There
are up to 31 save/recall registers available, so the total number of memory traces that can be present is 128
including the four active for the current instrument state. The memory data is stored as full precision,
complex data. Memory traces must be displayed in order to be saved with instrument states.
Additional data can be stored onto 3.5-inch floppy disks using the front panel disk drive.
NOTE You may not be able to store 31 instrument states if they include a large amount of
calibration data. The calibration data contributes considerably to the size of the instrument
state file and therefore the available memory may be full prior to filling all 31 registers.
Two trace math operations are implemented:
• (data/memory)
DATA/MEM
• (datamemory)
DATA-MEM
(Note that normalization is
trace math is done immediately after error-correction. This means that any data processing done after
error-correction, including parameter conversion, time domain transformation (Option 010), scaling, etc., can
be performed on the memory trace. You can also use trace math as a simple means of error-correction,
although that is not its main purpose.
All data processing operations that occur after trace math, except smoothing and gating, are identical for
the data trace and the memory trace. If smoothing or gating is on when a memory trace is saved, this state is
maintained regardless of the data trace smoothing or gating status. If a memory trace is saved with gating or
smoothing on, these features can be turned on or off in the memory-only display mode.
The actual memory for storing a memory trace is allocated only as needed. The memory trace is cleared on
instrument preset, power on, or instrument state recall.
If sweep mode or sweep range is different between the data and memory traces, trace math is allowed, and
no warning message is displayed. If the number of points in the two traces is different, the memory trace is
not displayed nor rescaled. However, if the number of points for the data trace is changed back to the
number of points in the memory, the memory trace can then be displayed.
If trace math or display memory is requested and no memory trace exists, the message CAUTION: NO
VALID MEMORY TRACE is displayed.
To Save a Data Trace to the Display Memory
Press
Display DATAMEMORY
active channel. The data trace is now also the memory trace. You can use a memory trace for subsequent
math manipulations.
To View the Measurement Data and Memory Trace
The analyzer default setting shows you the current measurement data for the active channel.
1. To view a data trace that you have already stored to the active channel memory, press:
not
DATA/MEM DATA-MEM
to store the current active measurement data in the memory of the
Making Measurements
Using Display Functions
.) Memory traces are saved and recalled and
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