Each tree structure forms a functional system. The base of the tree is called root,
e.g. MEASure and SYSTem. Each functional system can have subsystems of lower
level. The final nodes are called leaves. The entire sequence from root to the leaf
makes up the command. For example, part of SOURCe functional system looks as
follows:
:SOURce
:POWer
:CENTer
:STARt
:SPAN
:STOP
[:LEVel]
:SLOPe
[:DATA]
:STATe
This SOURce branch has several levels, where CENTer, STARt, SPAN, STOP, DATA,
STATe are the leaves, which represent the following six commands:
:SOURce:POWer:CENTer
:SOURce:POWer:STARt
:SOURce:POWer:SPAN
:SOURce:POWer:STOP
:SOURce:POWer[:LEVel]:SLOPe[:DATA]
:SOURce:POWer[:LEVel]:SLOPe:STATe
The tree can contain subsystems and leaves with the same names if they belong
to different branches, e.g. CENTer leaf is on the tips of different branches:
:SOURce :SENSe
:POWer :FREQuency
:CENTer :CENTer
3.3 Subsystems
A colon (':') separates the subsystems. The subsystems, which follow the colon are
of a lower level. For example, in command:
:SOURce:POWer:STARt
the start power STARt is a part of POWer subsystem, which is a part of SOURce
subsystem. The stop power is also a part of :SOURce:POWer subsystem. It is
specified by:
:SOURce:POWer:STOP
The first colon in the line can be omitted, for example:
SOURce:POWer:STOP