Many commands are supplemented by a parameter or a list of parameters. The parameters must be separated from the header by a "white space". Permissible parameters are numerical values, Boolean parameters, text, character strings and block data. The type of parameter required for the respective command and the permissible range of values are specified in the command description.
Numeric values can be entered in any form, i.e. with sign, decimal point and exponent. Values exceeding the resolution of the instrument are rounded up or down. The mantissa may comprise up to 255 characters, the values must be in the value range –9.9E37 to 9.9E37. The exponent is introduced by an "E" or "e". Entry of the exponent alone is not allowed. In the case of physical quantities, the unit can be entered. Permissible unit prefixes are G (giga), MA (mega), MOHM and MHZ are also permissible), K (kilo), M (milli), U (micro) and N (nano). If the unit is missing, the default unit is used.
Example:
SOUR:RFG:FREQ 1.5GHz is equivalent
to
SOUR:RFG:FREQ 1.5E9
Special numeric values
The texts MINimum, MAXimum, DEFault, UP and DOWN are interpreted as special numeric values. A query returns the associated numerical value.
Example:
Setting command: SENSe:FREQuency:STARt
MINimum
The query SENSe:FREQuency:STARt?
returns 300000 (the exact value depends on the analyzer model).
The following special values can be used:
Unless it is explicitly stated in the command description you can use the special numeric parameters for all commands of the analyzer.
Boolean parameters represent two states. The ON state (logically true) is represented by ON or a numerical value different from 0. The OFF state (logically false) is represented by OFF or the numerical value 0. A query responds with 0 or 1.
Example: Setting
command: SWEep:TIME:AUTO
ON
Query: SWEep:TIME:AUTO? returns 1
Text parameters observe the syntax rules for key words, i.e. they can be entered using a short or long form. Like any parameter, they have to be separated from the header by a white space. In the case of a query, the short form of the text is provided.
Example: Setting
command: TRIGger:SOURce
EXTernal
Query: TRIGger:SOURce? returns EXT
Strings must always be entered within single or double quotation marks (' or ").
Example: CONFigure:CHANnel:NAME "Channel
4" or
CONFigure:CHANnel:NAME 'Channel 4'
Block data is a transmission format which is suitable for the transmission of large amounts of data. A command using a block data parameter with definite length has the following structure:
Example: HEADer:HEADer #45168xxxxxxxx
The hash symbol # introduces the data block. The next number indicates how many of the following digits describe the length of the data block. In the example the 4 following digits indicate the length to be 5168 bytes. The data bytes follow. During the transmission of these data bytes all End or other control signs are ignored until all bytes are transmitted.
A #0 combination introduces a data block of indefinite length. The use of the indefinite format requires a NL^END message to terminate the data block. This format is useful when the length of the transmission is not known or if speed or other considerations prevent segmentation of the data into blocks of definite length.
: |
The colon separates the key words of a command. In a command line the separating semicolon marks the uppermost command level. |
; |
The semicolon separates two commands of a command line. It does not alter the path. |
, |
The comma separates several parameters of a command. |
? |
The question mark forms a query. |
* |
The asterisk marks a common command. |
', " |
Quotation marks introduce a string and terminate it. |
# |
The hash sign # introduces binary, octal, hexadecimal and block data. Binary: #B10110 |
|
A "white space" (ASCII-Code 0 to 9, 11 to 32 decimal, e.g. blank) separates header and parameter. |