98404704A
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1.2 Statistical Data Output Capability
The following data output capability is applicable only to the Model 4500A.
4500A Statistical Histogram GPIB Output.
The 4500A statistical histogram count array accumulated by running a CDF, 1-CDF or PDF
function is output in two arrays of 4096 values each.
1.
The X-axis array consists of up to 4096 power values in watts or dBm as described
above. The bus commands LIN and LOG are used to set the units. The Channel 1
array is selected by the command SELDATTBL 6 and the Channel 2 array by
SELDATTBL 7. The array is returned by the talk mode command TK-TBLDAT n,
where n is the starting index number. The BUFCOUNT command followed by a
count argument of 1 to 4096 operates as described above for the TKFPDISP
command.
2.
The Y-axis array consists of up to 4096 count values. The count value is the number
of times the power sample value has fallen within the bin located by the index
number. The power in watts or dBm for the center of each bin or index number is
given by the X-axis array above. The ratio of each bin count to the total sample count
is the probability of occurrence for that bin. The Channel 1 count array is selected by
the command SELDATTBL 8 and the Channel 2 count array by SELDATTBL 9. The
array is returned by the talk mode command TK-TBLDAT n, where n is the starting
index number. The BUFCOUNT command followed by a count argument of 1 to
4096 operates as described above for the TKFPDISP command.
4500A Front Panel Histogram Output.
Front panel histogram output is controlled by the
Prgm>Trace Data>
menu. An entire data buffer can be sent to a Floppy Disk file, the COM1
serial port or the LPT1 line printer. No index value is used. The delimiter separating data
elements can be selected to be a comma, LF (line-feed or NL), CR (carriage return) or ASCII
space. This is useful if the data file is to be imported directly into a spreadsheet.
For the Model 4500A, additional source choices will appear in the menu as follows:
Prgm>Trace Data>Source
Select the data buffer: CH1, CH2, CH Math, Ref1, Ref2,Cal
Tbl 1,Cal Tbl 2,Histogram 1,Histogram2
Cal Tbl 1 and 2 are the x-axis power value arrays and Histogram 1 and 2 are the count arrays for
Channel 1 and 2 respectively. All other front panel controls and associated GPIB commands
operate as described above except that the SELDATTBL n, command is used instead of the data
source commands.