Rubidium™ MG362x1A SeriesLow-Noise RF/Microwave SignalGenerators : Programming with SCPI Commands : Notational Conventions
Notational Conventions
The SCPI interface standardizes command syntax and style that simplifies the task of programming across a wide range of instrumentation. As with any programming language, the exact command keywords and command syntax must be used. Unrecognized commands, or improper syntax, will generate an error (refer to Error Messages for error reporting).
General Notations
The syntax conventions that are used for all SCPI command keywords and data parameter descriptions in this manual are described below:
A colon links command keywords together to form commands. The colon is not an actual part of the keyword but is a signal to the SCPI interface parser. A colon must precede a root keyword immediately following a semicolon (See Notational Examples).
A semicolon separates commands if multiple commands are placed on a single program line (See Notational Examples).
Square brackets enclose one or more optional parameters.
Braces enclose one or more parameters that may be included one or more times.
A vertical bar indicates “or” and is used to separate alternative parameter options.
For example: ON|OFF is the same as ON or OFF.
Angle brackets enclose parameter descriptions.
Means “is defined as” For example: <a>::=<b><c> indicates that <b><c> can replace <a>.
Space(s), referred to as whitespace, must be used to separate keywords from their associated data parameters. It must not be used between keywords, or inside keywords.
For further information about SCPI command syntax and style, refer to the Standard Commands for Programmable Instruments (SCPI) 1993.0 document.
Parameter Notations
The following syntax conventions are used for all data parameter descriptions in this manual
::= a generic command argument consisting of one or more of the other data types.
::= boolean values in <NR1> format; numeric 1 or 0.
::= ON|OFF. Can also be represented as 1 or 0, where 1 means ON and 0 means OFF. Boolean parameters are always returned as 1 or 0 in <NR1> format by query commands.
::= an unsigned integer without a decimal point (implied radix point).
::= a signed integer without a decimal point (implied radix point).
::= a signed number with an explicit radix point.
::= a scaled explicit decimal point numeric value with and exponent (e.g., floating point number).
::= <NR1>|<NR2>|<NR3>.
::= SCPI numeric value: <NRf>|MIN|MAX|UP|DOWN|DEF|NAN|INF|NINF or other types.
::= <STRING PROGRAM DATA> ASCII characters surrounded by double quotes, example: “OFF”.
::= IEEE-488.2 block data format.
::= Not Applicable.
Notational Examples
The following is an example showing command syntax (It is not an actual command):
[SOURce]:POWer[:LEVel][:IMMediate][:AMPLitude]:STEP[:INCRement] sp dBm|DOWN|UP
Command statements read from left to right and from top to bottom. In the command statement above, the :STEP keyword immediately follows the :AMPLitude keyword with no separating space. A space (sp) is used between the command string and its argument (a <nv> type data parameter).
Note that the first keyword in the command string does not require a leading colon; however, it is good practice to always use a leading colon for all keywords. Note also that the :SOURce keyword is optional. This is a SCPI convention for all voltage or signal source type instruments that allows shorter command statements to be used.
The following is an example of a multiple command statement that uses two separate commands in a single statement. Note the semicolon used to join the commands. (Also note the leading colon used immediately after the semicolon.)
:FREQuency:STARt 10E6;:FREQuency:STOP 20E9