Operating instructions

Introduction To Programming
18
Note Ignore the meanings of these commands for now. All keywords are defined in the Language Dictionary
and command functions are explained in the electronic load Operating Manual.
Figure 3-1 shows the RESistance commands, which form a typical branch that forms a ’’subtree" of its own. You can see
that the RESistance branch has three subbranches; LEVel, RANGe, and TLEVel. When it reaches the end of a branch, the
parser expects a parameter, a question mark (that identifies the keyword as a query), a semicolon or semicolon-colon
combination, or an end-of-line terminator.
.
Figure 3-1. RESistance Branch Subtree
Figure 3-2 is the syntax diagram for the RESistance branch. You can still identify the tree structure, although it runs from
left-to-right instead of from top-to-bottom. Note the following symbols that were discussed in Chapter 2-Introduction to
HPSL.
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Keywords with the short form shown in bold-faced capital letters. Implied keywords are not within brackets in
diagrams.
•
Spaces shown as "SP" within circles.
•
Boxes showing the form (NRf + ) of the parameter.
•
Boxes showing optional suffixes. Multipliers are not shown.
•
Question marks that convert a command into a query
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Colons (:) that precede each keyword. They are important and are discussed later in more detail.
Traversing The RESistance Branch
From Figure 3-2 note that there are two implied keywords that you can usually ignore. This makes two of the commands
very simple. If you enter:
RES 1.5
you will send the electronic load an immediate resistance level command. The command actually is:
RES:LEV:IMM 1.5