Agilent Technologies Infiniium 90000 Q-Series, Programmer'S Manual

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Programming Conventions
8
Agilent Infiniium 90000 Series Oscilloscopes Programmer's Reference 139
The Command Tree
The command tree in this document's table of contents shows all of the
commands in the Infiniium- Series Oscilloscopes and the relationship of the
commands to each other. The IEEE 488.2 common commands are not part
of the command tree because they do not affect the position of the parser
within the tree.
When a program message terminator (<NL>, linefeed - ASCII decimal 10)
or a leading colon (:) is sent to the oscilloscope, the parser is set to the
"root" of the command tree.
• "Command Types" on page 139
• "Tree Traversal Rules" on page 139
• "Tree Traversal Examples" on page 140
Command Types
The commands in this oscilloscope can be viewed as three types: common
commands, root level commands, and subsystem commands.
• Common commands are commands defined by IEEE 488.2 and control
some functions that are common to all IEEE 488.2 instruments. These
commands are independent of the tree and do not affect the position of
the parser within the tree. *RST is an example of a common command.
• Root level commands control many of the basic functions of the
oscilloscope. These commands reside at the root of the command tree.
They can always be parsed if they occur at the beginning of a program
message or are preceded by a colon. Unlike common commands, root
level commands place the parser back at the root of the command tree.
AUTOSCALE is an example of a root level command.
• Subsystem commands are grouped together under a common node of
the command tree, such as the TIMEBASE commands. You may select
only one subsystem at a given time. When you turn on the oscilloscope
initially, the command parser is set to the root of the command tree
and no subsystem is selected.
Tree Traversal Rules
Command headers are created by traversing down the command tree. A
legal command header from the command tree would be
:TIMEBASE:RANGE. This is referred to as a compound header. A
compound header is a header made up of two or more mnemonics
separated by colons. The compound header contains no spaces. The
following rules apply to traversing the tree.