Implied Implied commands appear in square brackets ([ ]) in the command syntax. (Note Commands 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 this excerpt from the STATus subsystem shown below:

STATus:

OPERation

[:EVENt]?

The third level command, EVENt, is implied. To read the value of the Event Register, you can use either:

STATus:OPERation?

or

STATus:OPERation:EVENt?

Parameters Parameters are enclosed in greater than/less than symbols (< >) in the command syntax. When more than one parameter is allowed, the parameters are separated by a vertical line ( ).

Parameter Types. The following table contains explanations and examples of parameter types you might see later in this chapter. Parameters must always be separated from the keywords by a space.

Parameter Type

Explanations and Examples

 

 

 

 

Numeric

Accepts all commonly used decimal representations of

 

numbers including optional signs, decimal points, and

 

scientific notation.

 

123, 123E2, -123, -1.23E2, .123, 1.23E-2, 1.23000E-01.

 

Special cases include MIN, MAX, and DEF.

 

 

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 SOURcen:FUNCtion:MODE <mode>

 

command where the <mode> parameter can be either

 

CURRent or VOLTage.

 

 

 

 

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.

Chapter 3

HP E1418A SCPI Command Reference 61