GW Instek APS-1102A, User Manual, Page: 199 / 285

6 REMOTE INTERFACE
APS-1102A 6-15
d) Subsystem commands
Subsystem commands are commands used to execute the particular functions of devices.
Subsystem commands correspond to a measuring instrument internal function groups, with several
sets divided into groups. Each subsystem command has a tree structure, and colon (:) is defined as a
path separators.
1) SCPI command tree
Figure 6-2
shows a partial command tree of subsystem commands.
See Figure 6-3 for an overview of the command tree.
Figure 6-2. Partial Command Tree

Root level
The command tree top level is the root. With SCPI, the current path is set to the root, as shown
below.
○ Immediately after the device power source goes on
○ When the device receives a “root specifier”
The root specifier is a colon (:) that is attached to the start of a command string to indicate
that the current path is set to the root.
○ When the device has received a “message terminator”
The message terminator is a line feed (LF) at the end of an SCPI message. The current path is
returned to the root level when the device receives a message terminator.

Current path
The current path is a command level within the command tree, which specifies the command
level that will be searched first when the user sends a command.