The command is correct and will not cause errors. It is equivalent to sending:

“FREquency : CW 5 GHZ ; : FREUuency :MULTiplier 2”.

Example 2: “FREquency 5 GHZ; MULTiplier 2”

This command results in a command error. The command makes use of the default [:CW] node. When using a default node, there is no change to the current path position. Since there is no command “MULT” at the root, an error results. A correct way to send this is: “FREIJ 5 GHZ ; FREq : MULT 2” or as in example 1.

Example 3: “FREquency:MULTiplier 2; MULTiplier:STATE ON;

FREUuency : CW 5 GHZ”

This command results in a command error. The FREQ:CW portion of the command is missing a leading colon. The path level is dropped at each colon until it is in the FREQ:MULT subsystem. So when the FREQ:CW command is sent, it causes confusion because no such node occurs in the FREQ:MULT subsystem. By adding a leading colon, the current path is reset to the root. The corrected command is:

“FREquency:MULTiplier 2; MULTiplier:STATE ON; :FREquency:CW 5 GHZ”.

Example 4: “FREU 5 GHZ; POWER 4 DBM”

Notice that in this example the keyword short form is used. The command is correct. It utilizes the default nodes of [:CW] and [:LEVEL]. Since default nodes do not affect the current path, it is not necessary to use a leading colon before POWER.

Parameter Types

As you saw in the example command table for SWEep, there are several types of parameters. The parameter type indicates what kind of values are valid instrument settings. The most commonly used parameter types are numeric, extended numeric, discrete, and Boolean. These common types are discussed briefly in the following paragraphs. The paragraph titled “Details of Commands and Responses” explains all parameter types in greater depth.

Numeric Parameters. Numeric parameters are used in both subsystem commands and common commands. Numeric parameters accept all commonly used decimal representations of numbers including optional signs, decimal points, and scientific notation. If an instrument accepts only specific numeric values, such as integers, it automatically rounds numeric parameters to fit its needs.

Examples of numeric parameters:

100

no decimal point required

100.

fractional digits optional

- 1 . 2 3

leading signs allowed

4.56e<space>3

space allowed after e in exponents

Getting Started Programming 1-73