1321
Trace/Detector
Math: More Information
IMPORTANT: to generate a trace math result, you must take a sweep. The trace math engine, described
below, operates in concert with the sweep engine in the test set. Until a sweep has been taken, even if
the constituent traces are not in Update mode, no result is generated. Note that certain events can affect
the trace in ways that affects all points at once. This can happen in any number of ways, including:
A trace clear taking place
A trace being loaded from the file system
Trace data being sent in from the remote interface
A copy or exchange of trace data
You should try to avoid these occurrences during a sweep, as they will tend to invalidate the math result
being accumulated.
How trace math is processed:
Whenever a trace math function is turned on, or the parameters and/or operands of an existing trace math
function are changed, the destination trace is cleared. After the trace is cleared, all x-axis values in the
trace, and the domain of the trace, are set to match the X-axis settings of the first trace operand. When
this is complete, a new sweep is initiated.
The process of acquiring data, processing it using the math and average/hold functions, and presenting it
to the user as trace data, consists of several functional blocks, as shown below:
For each active trace, the current trace point is processed for Trace 1, then Trace 2, then Trace 3, et
cetera. Trace data is taken from either the detector for that trace, or from the mathematical result of up to
two other traces and an offset, depending on whether trace math is on or not. The resultant data is then
fed to the Average/Hold processing block, where (if the trace type is A verage, Max Hold, or Min Hold) it
is processed with previous trace data. The new trace data resulting from this process is then available for
display, storage or remote output.
When the processing is complete for Trace 1, Trace 2 is processed, and so on until all six traces have
been processed. This allows a downstream trace to use as one of its math components a fully processed
upstream trace. In other words, if math is on for Trace 4, and its operand traces are Trace 2 and Trace 3,
all detector, math, average and hold processing for traces 2 and 3 is complete before the math is
performed for trace 4. When the current trace point is completed for all traces, the test set moves on to
the next trace point.
Detector
Math:
First Operand Trace
SENSe
Math Off
Math On
Math
Processing
Math:
Second Operand Trace Average/Hold
Processing
Trace from
previous sweep
New Trace
Trace from Detector
Offset (User Specified)
CALCulate:MATH
Note does not update if
Update=Off