Operating instructions

Introduction To Programming

RES MAX < nl >

Note MAX and MIN are the maximum and minimum values allowed in the present operating mode of the

electronic load. For the electronic load this generally means the limits within the present range.

MAX and MIN may also be used with queries to find the maximum and minimum permitted settings of the present mode.

For example:

RES? MAX Returns the maximum permitted value of the present range

Traversing The Command Tree

Note The HPSL parser traverses the command tree as described in Appendix A of IEEE 488.2 Standard

Digital Interface for Programmable Instrumentation. The Enhanced Tree Walking Implementation

given in that appendix is not implemented in HPSL . The simplified explanation given here is sufficient

for using the electronic load command set in most applications.

Use of the Colon

When you examined the RESistance branch, you noticed the colon (:) that separated keywords from each other. A colon

represents a change in branch level. ROOT is the highest level. Whenever you enter a (:), the parser expects it to be

followed by a command of the next lower level. For example:

INP:PROT:CLE

CURR:LEV:TRIG

INP and CURR are root-level commands. PROT and LEV are first branches, and CLE and

TRIG are second branches. Each (:) instructs the parser to move down to the next branch.

Note A colon after a keyword always moves the parser down, never up the command tree.

If you enter INP:PROT:CLE:, you will get an error because the parser expects to find another keyword after the last (:). In

this example, you will also get an error if you enter INP:PROT because another keyword is required after PROT.

However, a command like MODE:RES is o.k. because no keyword or parameter is expected after RES. You will know

what is required in each case by referring to the Language Dictionary.

Use of the Semicolon

The semicolon (;) is a "back-up" command. It instructs the parser to return to the previous colon. Figure 3-3 illustrates how

the semicolon moves the parser backwards.

Note The semicolon by itself can back the parser up to a colon only within the same branch.

The semicolon allows you to combine command statements on one line to create command messages.

VOLT:SLEW 5000 < nl > Statements are on separate lines

VOLT:TLEV 55 < nl >

VOLT: SLEW 5000;TLEV 55 < nl > Combined statements form a message