FAQs from Rohde & Schwarz

Wrong Number of y-values when querying a Trace

Question

When I query the trace with a certain number of sweep points, I get the wrong number of y-values back.

For example, if I set the number of sweep points to 1000, I get 1001 y-values back. So I do not know how

to assign the x-values (frequency) to the y-values (level).

Answer

The number of sweep points can only be set to certain values.

The following steps are possible:

FSP: 125, 251, 501, 1001, 2001, 4001, 8001,

FSQ: 155, 313, 625, 1251, 1999, 2501, 5001, 10001, 20001, 30001

FSU(P): 155, 313, 625, 1251, 1999, 2501, 5001, 10001, 20001, 30001

If a number between these steps is set, the next higher value is selected. Coming back to the example:

If the number of sweep points is set to 1000, 1001 points will be selected.

In this case, set the number of sweep points to 1001 and the x and y-values will match.

The FSL and FSV(R) allow any number of sweep points between 101 to 32001 to be selected, so you will

not see this effect with these two instruments.