Agilent Technologies E1441A user service Linking Commands, Implied Commands, Parameters

Implied Commands

Implied commands are those which appear in square brackets ([ ]) in the command syntax. (Note that the brackets are not part of the command and are not sent to the instrument.) Suppose you send a second level command but do not send the preceding implied command. In this case, the instrument assumes you intend to use the implied command and it responds as if you had sent it. Examine the partial SOURce subsystem shown below:

[SOURce:] FUNCtion

[:SHAPe] "<shape>"(e.g., <shape> = SQUare) [:SHAPe]?

FREQuency <frequency> MINimum MAXimum FREQuency? [ MINimumMAXimum ]

The root command SOURce: is an implied command. For example, to set the function generator's function to a square wave, you can send either of the following command statements:

SOUR:FUNC SQU or FUNC SQU

Parameters

Linking Commands

Parameter Types. The following table contains explanations and examples of parameter types you might see later in this chapter.

Parameter Type	Explanations and Examples
Numeric	Accepts all commonly used decimal representations of number
	including optional signs, decimal points, and scientific notation.
	123, 123E2, -123, -1.23E2, .123, 1.23E-2, 1.23000E-01.
	Special cases include MINimum, MAXimum, and DEFault.
Boolean	Represents a single binary condition that is either true or false.
	ON, OFF, 1, 0
Discrete	Selects from a finite number of values. These parameters
	use mnemonics to represent each valid setting.
	An example is the TRIGger:SOURce <source> command where
	source can be BUS, EXT, or IMM.

Optional Parameters. Parameters shown within square brackets ([ ]) are optional parameters. (Note that the brackets are not part of the command and are not sent to the instrument.) If you do not specify a value for an optional parameter, the instrument chooses a default value. For example, consider the AM:DEPTh? [MIN MAX] command. If you send the command without specifying a MINimum or MAXimum parameter, the present AM:DEPTh value is returned. If you send the MIN parameter, the command returns the minimum AM modulation depth available. If you send the MAX parameter, the command returns the maximum AM modulation depth available. Be sure to place a space between the command and the parameter.

Linking IEEE 488.2 Common Commands with SCPI Commands. Use a semicolon between the commands. For example:

*RST;OUTP:LOAD INF or TRIG:SOUR BUS;*TRG

Linking Multiple SCPI Commands. Use both a semicolon and a colon between the commands. For example:

OUTP:LOAD 50;:APPL:RAMP

Chapter 3 Agilent E1441A SCPI Command Reference 71