1.6 Data Type
SCPI language defines several data types used for program message and re-
sponse messages.
•
Numerical parameter
Commands requiring numerical parameter support the notations of all com-
mon decimal notations, including optional signs, decimal points, scientific
notation, etc. Special values of numerical Parameter are also acceptable,
such as MIN, MAX and DEF. In addition, suffixes for engineering units can
also be sent together with numerical Parameter (including M, k, m or u). If
the command accepts only some specific values, the instrument will auto-
matically round the input Parameter to acceptable values. The following
commands require numerical Parameter of frequency value:
[SOURce[1|2]:]FREQuency:CENTer {<Frequency>|MINimum|
MAXimum}
–
<NR1>
: represents an integer value, such as 273;
–
<NR2>
: represents a real number in floating-point format, such as .273;
–
<NR3>
: represents a real number in scientific notation, such as 2.73E+2;
–
<Nrf>
: The extensible form includes <NR1>, <NR2> and <NR3>;
–
<Nrf+>
: The extensible decimal form includes <Nrf>, MIN, MAX and
DEF. MIN and MAX are the minimum and maximum finite number. Within
the range of the parameter definition, DEF is the default of the
parameter.
•
Discrete parameter
Discrete Parameter are used for settings with limited number of program-
ming values (such as IMMediate, EXTernal or BUS). They can use short and
long format like key words of commands. They may be expressed in both
upper and lower case. The query response always returns uppercase pa-
rameter in short format. The following commands require discrete parameter
in voltage unit:
[SOURce[1|2]:]VOLTage:UNIT {VPP|VRMS|DBM}
•
Boolean parameter
Boolean parameter refer to true or false binary conditions. In case of false
conditions, the instrument will accept "OFF" or "0". In case of true conditions,
the instrument will accept "ON" or "1". In query of Boolean settings, the in-
strument will always return "0" or "1". Boolean parameter are required by the
following commands:
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