Front Panel Description
The front panel includes a
current of that channel. By using the 
key you can sequentially display input power, programming error codes, and 
key. If you change channels via the front panel, any fault information will be displayed first for the new channel. Then you can key through the display in the normal sequence. The alphanumeric display also shows what function is being performed when you use the keypads.
The display also includes 11 annunciators that point to the 11 status labels printed on the front panel. The Constant Current, Constant Resistance, Constant Voltage, Transient, and Unregulated status annunciators are specific to the channel displayed. The Protection, Error, Shift, Remote, Address, and Service ReQuest status annunciators are channel independent.
Four of the keys perform two functions, with the alternative function labeled in blue above the key. The alternative function is selected by first pressing the blue (shift) key, which turns on the Shift annunciator and enables the alternative function.
Note that the
Remote Programming
Commands sent to the Electronic Load via GPIB are decoded by the mainframe microprocessor, which detects syntax and range errors. The mainframe processor also prescales data sent to the modules, and maintains status registers for each module. Three commands have aliases for compatibility with other HPSL instruments. MODE can also be called FUNCtion, INPut can also be called OUTPut, and CHANnel can also be called INSTrument. OUTPut and INSTrument would typically be used if you want your program to refer to the load modules in terms of the device or instrument under test. Be careful if using INSTrument for CHANnel in systems that have more than one Electronic Load mainframe; someone looking at the listing in the future may be misled.
Local/Remote Control
Local (front panel) control is in effect immediately after power is applied. The front panel keypad and display allow manual control of each individual module when the Electronic Load is used in bench test applications. Remote (computer) control goes into effect (front panel Rmt annunciator is on) as soon as the mainframe receives a command via the GPIB. A
With remote control in effect, only the computer can control the Electronic Load; the front panel keypad has no effect. You can, however, still use the front panel display to view the input voltage and current readings. You can return the Electronic
Load to local control from remote control by pressing 
. This will return the Electronic Load to local control, unless the
Most of the functions that can be performed remotely over the GPIB can also be performed locally at the front panel. The names on the keys reflect the HPSL commands that are used to program the various functions. Consequently, learning to operate the Electronic Load from the front panel will aid you when you start to write computer programs.
Details of local operation are covered in Chapter 4 - Local Operation and fundamentals of remote programming are given in Chapter 5 - Remote Operation. Complete HPSL programming details are given in the Agilent Electronic Loads Programming Reference Guide. The remaining paragraphs in this chapter describe the operating modes, transient
