Language Reference

WLUNITS

Example Determine the wavelength that corresponds to a point's relative position on a trace.

10

CLEAR 723

Initialize analyzer .

20

OUTPUT 723;"IP;";

 

30

OUTPUT 723;"CLRDSP;"

Clear graphics from memory .

40

OUTPUT

723;"PU;PA 200,700;"

Place pen up , then move it to (200,700).

50

OUTPUT

723;"TEXT$8th element is $;"

Write text.

60OUTPUT 723;"DSPLY WLUNITS 8,TRA,7,2;" Display wavelength value of 8th element in trace A.

70 OUTPUT 723;"TEXT$M$;"

Print \M" after variable .

Description The WLUNITS command converts a trace point indicated in position units to wavelength. In zero-span mode, position units are converted to units of time.

A position unit describes the position of a point along the horizontal axis of a trace. The point at the left end of the trace has a position-unit value of 1. The point at the right end of an 800-point trace has a position-unit value of 800. If a reference trace is not indicated, the number of points in the currently active or last active trace is assumed for WLUNITS operations and the conversion is based on the wavelength values of that trace.

WLUNITS must be used either as a query or as an argument to another function. Form a query by ending the WLUNITS statement with a question mark (?). When used as a query, WLUNITS gives the wavelength value of the speci￿ed trace position. Use WLUNITS as an argument by incorporating the WLUNITS statement into the source of any spectrum-analyzer command having prede￿ned function in its syntax diagram. When used as a source, WLUNITS uses the wavelength value of the speci￿ed point for operation by the command that contains WLUNITS.

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