Using Variables and Traces

Using Math and Move Commands

Trace Math Rule 2

￿Trace elements greater than +32,767 and less than 032,768 are truncated.

Math operations are restricted to the legal range of measurement units when trace arrays or elements form the destination or source.

10 OUTPUT 723;"MPY TRA[100],1000,1000;"

Multiplies 1000 times 1000, then stores

 

truncated value (32,767) in trace element.

Trace Math Rule 3

￿When the source is a real number or variable and the destination is a trace array or element, use the MEASU command to preserve decimal values and yield parameter units

The source and destination express numbers in di￿erent units, making a conversion necessary. All trace amplitude information is stored internally and manipulated in measurement units. If the conversion to measurement units is omitted, returned data is inaccurate by a factor of 100 and signi￿cant digits may be lost.

In the following example, the marker is assumed to be marking a signal at 010.33 dBm.

10

OUTPUT

723;"MOV TRB[100],MKA;"

Copy integer value of marker ( 010)

 

 

 

into trace B element. TRB[100] now

 

 

 

contains 010 measurement units .

20

OUTPUT

723;"TRB[100]?;"

Return 00.1 dBm (false value).

In following example uses the MEASU command to preserves decimal values and returns trace amplitude values in parameter units.

10

OUTPUT 723;"MOV TRB[100],MEASU MKA;"

Convert marker amplitude (010.33)

 

 

to measurement units , then move

 

 

value (01033) into trace element.

 

 

TRB[100] now contains 01033 mea-

 

 

surement units .

20

OUTPUT 723;"TRB[100]?;"

Return 010.33 (correct value).

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