Argantix XDS 100-100, User And Programming Manual

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User and Programming Manual
XDS Series 81
The SCPI Command Tree
As previously explained, the basic SCPI communication method involves sending one or more
properly formatted commands from the SCPI command tree to the instrument as program messages.
The following figure shows a portion of a subsystem command tree, from which you access the
commands located along the various paths (you can see the complete tree in appendix A).
Root
[:SOURce] :VOLTage [:LEVel]
:CURRent :RANGe
:SYSTem :REMote
:ERRor
:LIMit :VOLTage :LOW?
:HIGH?
Figure 10-1: Partial Command Tree
The Root Level
Note the location of the ROOT node at the top of the tree. Commands at the root level are at the top
level of the command tree. The SCPI interface is at this location when:
•
The Power supply is powered on
•
A device clear (DCL) is sent to the Power supply
•
The SCPI interface encounters a message terminator
•
The SCPI interface encounters a root specifier
Active Header Path
In order to properly traverse the command tree, you must understand the concept of the active
header path. When the Power supply is turned on (or under any of the other conditions listed above),
the active path is at the root. That means the SCPI interface is ready to accept any command at the
root level, such as SOURCe or MEASurement.
If you enter SOURCe the active header path moves one colon to the right. The interface is now ready
to accept :VOLTage or :CURRent as the next header. You must include the colon, because it is
required between headers.
Note: The XDS Series interface buffer is limited to 21 characters, however. As such, compound
commands are not recommended as they often exceed this message length limit.