The commands consist of a so-called header and, in most cases, one or more parameters. Header and parameter are separated by a "white space" (ASCII code 0 to 9, 11 to 32 decimal, e.g. blank). The headers may consist of several key words. Queries are formed by directly appending a question mark to the header.
Common Commands
Common (=device-independent) commands consist of a header preceded by an asterisk "*" and possibly one or more parameters.
| Examples: |
|
RESET, resets the instrument. |
|
EVENT STATUS ENABLE, sets the bits of the event status enable registers. | |
|
EVENT STATUS QUERY, queries the contents of the event status register. |
Device-specific commands
| Hierarchy: | Device-specific commands are of hierarchical structure (see figure below). The different levels are represented by combined headers. Headers of the highest level (root level) have only one key word. This key word denotes a complete command system. |
| Example: SOURce This key word denotes the command system SOURce. | |
| For commands of lower levels, the complete path has to be specified, starting on the left with the highest level, the individual key words being separated by a colon ":". | |
Example: SOURce:RFGenerator:FHOPping:STATe
ON
This command is located on the fourth level of the SOURce system. It switches on frequency hopping for the RF generator. |
Example for the tree structure of the SCPI command systems; the SOURce system
| Multiple key words |
Some key words occur on several levels within one command system. Their effect depends on the structure of the command, i. e. on the position in the command header they are inserted in. |
Example: SOURce:RFGenerator:FHOPping:STATe
ON | |
This command contains the key word SOURce in
the first command level. It switches on frequency hopping for the RF generator. | |
|
| |
This command contains the key word SOURce in
the second command level. It defines the trigger source "external
trigger". | |
| Optional key words: |
Some command systems permit certain key words to be optionally inserted into the header or omitted. These key words are marked by square brackets in this manual. The full command length must be recognized by the instrument for reasons of compatibility with the SCPI standard. Some commands are considerably shortened by omitting optional key words. |
Example: TRIGger[:SEQuence]:SOURce
EXTern | |
This command defines the trigger source "external trigger".
The following command has the same effect: | |
| Note: An optional key word must not be omitted if its effect is additionally specified by a numeric suffix. | |
| Long and short form: | The key words feature a long form and a short form. Either the short form or the long form can be entered, other abbreviations are not permitted. |
Example:
| |
| Note: The short form is marked by upper-case letters, the long form corresponds to the complete word. Upper-case and lower-case notation only serves to distinguish the two forms in the manual, the instrument itself does not distinguish upper-case and lower-case letters. | |
| Parameters: | Parameters must be separated from the header by a "white space". If several parameters are specified in a command, they are separated by a comma ",". For a description of the types of parameter, refer to section Parameters. |
Example: CONFigure:POWer:CONTrol:REPetition
SINGleshot, SONerror, NONE | |
| This command sets parameters to define the statistics of a power measurement. | |
| Numeric suffix: | If a device features several functions or features of the same kind, e.g. several inputs, the desired function can be selected by a suffix added to the command. Entries without suffix are interpreted like entries with the suffix 1. |
Example: SOURce:CORRection:LOSS:INPut2
10dB | |
| This command defines the external attenuation at the input connector RF 2 |
