Operating instructions

Introduction To Programming
17
3
Introduction To Programming
Types Of Commands and Queries
The electronic load responds to two types of commands and queries, Common and Root. Common commands were
introduced in Chapter 2-Introduction to HPSL and are relatively simple to use. The root commands are organized in a
hierarchy that is best shown via a command tree diagram.
Understanding The Command Tree
Figure 4-2 in Chapter 4-Language Dictionary is a tree diagram of all the root commands for the electronic load. Notice the
following:
•
The originating point of the diagram is at the root. In this case, the diagram resembles an inverted tree. "Root" is not a
command, but the origin for all commands.
•
The root divides into two major branches-Channel-Specific commands and Channel-Independent commands. Both
types are accepted by all electronic loads.
•
Each major branch divides into several branches. The CURRent commands are a branch. The VOLTage commands
are another branch. So are the TRlGger commands.
•
Some keywords are within brackets [ ]. These are implied keywords. Implied keywords are optional, but you may want
to use them in certain situations (See Implied Keywords, later in this chapter).
Note For fastest program execution, omit implied keywords.
•
Commands followed by ? are queries. They cause the electronic load to store information in its output buffer from
where it can be read by the controller over the GPIB.
Understanding A Typical Branch
Here are the keywords for the RESistance branch as they appear in Chapter 4-Language Dictionary:
Command and Function
RESistance[:LEVel][:IMMediate]
Specify input resistance for RESistance mode
RESistance[:LEVel]:TRlGgered
Preset input resistance level pending trigger occurrence
RESistance:RANGe
Specify full-scale resistance input range
RESistance:TLEVel
Specify resistance level for TRANsient function