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S:\agilent\8920\8920b\PRGGUIDE\BOOK\CHAPTERS\usehpib.fb
Chapter 1, Using GPIB
Overview of the Test Set
Internal Automatic Control Mode In Internal Automatic Control mode the Test Set’s operation is controlled by an
application program running on the built-in Instrument BASIC (IBASIC)
Controller. The built-in controller runs programs written in IBASIC, a subset of
the HP® BASIC programming language used on the HP® 9000 Series 200/300
System Controllers. IBASIC is the only programming language supported on the
built-in IBASIC Controller.
Similarities Between the Test Set’s IBASIC Controller and Other Single-Tasking
Controllers
The architecture of the IBASIC Controller is similar to that of ot her singl e-taski ng
instrumentation controllers. Only one program can be run on the IBASIC
Controller at any given time. The program is loaded into RAM memory from
some type of mass storage device. Five types of mass storage devices are
available to the Test Set: SRAM memory cards, ROM memory cards, external
disk drives connected to the GPIB interfac e, internal RAM disc, and internal
ROM disc. Three types of interfaces are available for connecting to external
instruments and equipment: GPIB, RS-232, and 16-bit parallel (available as Opt
020 Radio Interface Card).
Figure 2 shows how information is routed inside the Test Set when it is in Internal
Automatic Control mode. In Manual Control mode certain Test Set resources are
dedicated to manual operation. These resources are switched to the IBASIC
Controller when an IBASIC program is running. These include the serial interface
at select code 9, the GPIB interface at select code 7, the parallel printer interface at
select code 15, and the CRT. In Manual Control mode, front panel information
(instrument settings, measurement results, data input from the DUT) is routed to
the CRT through the To Screen control hardware. In Internal Automatic Control
mode the measurement results and data input from the DUT are routed to the
IBASIC Controller through a dedicated GPIB interface. Also, in Internal
Automatic Control mode, the CRT is dedicated to the IBASIC Controller for
program and graphics display. This means instrument front panels cannot be
displayed on the CRT when an IBASIC program is running.