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Model N6705 User's Guide
the amplitude range of each bin of the histogram and the value of the
bin that the sampled value falls within is incremented by 1. There is
some overlap between the lowest bins of the high range and the
highest bins of the low range; values that overlap both ranges are
placed in the low range buckets. Each Fetch returns the latest
cumulative histogram data. The measurement continues until it is
aborted. The count bins are 64-bits wide, which eliminates any
concern for overflow.
Terminate the Measurement
Measurements continue until the histogram is aborted. To abort the
histogram measurement:
ABOR:HIST (@1)
Retrieve the Histogram Measurement
The following command returns the histogram counts for the 3.9 mA
histogram range from output 1:
FETC:HIST:CURR? 0.0039,(@1)
The following command returns the histogram counts for the 8 A
histogram range from output 1:
FETC:HIST:CURR? 8,(@1)
Histogram data is returned as 4096 comma-separated ASCI values
terminated by a newline. A histogram query can only fetch data from
one histogram range at a time.
Query the Histogram Bin and Offset to Calculate Amperes
The gain and offset are needed to convert a bin number to amperes.
Therefore, the bin gain and offset can be queried for each histogram
range. For example, to query the gain and offset value for the 3.9 mA
histogram range, use:
SENS:HIST:CURR:BIN:GAIN? 0.0039,(@1)
SENS:HIST:CURR:BIN:OFFS? 0.0039,(@1)
To query the gain and offset value for the 8 A histogram range, use:
SENS:HIST:CURR:BIN:GAIN? 8,(@1)
SENS:HIST:CURR:BIN:OFFS? 8,(@1)
The median current in amperes of a bin can then be calculated using:
current = (bin number) x gain + offset
where (bin number) is an integer number between 0 and 4095
corresponding to the 4096 counts returned by FETC:HIST:CURR?
Because the current measurements can be positive or negative, bin 0
represents the most negative current, bin 2048 represents 0, and bin
4095 is the most positive current.
Advanced Source and Measurement Functions 6
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