HP 8920B, Programmer'S Manual

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21
Chapter 1, Using HP-IB
Overview of the Test Set
Differences Between the Test Set’s IBASIC Controller and Other Single-Tasking
Controllers
The IBASIC Controller is unlike other single tasking instrumentation controllers
in several ways. First, it does not have a keyboard. This imposes some limitations
on creating and editing IBASIC programs directly on the Test Set. In Internal
Automatic Control mode a “virtual” keyboard is available in firmware which
allows the operator to enter alphanumeric data into a dedicated input field using
the rotary knob. This is not the recommended programming mode for the IBASIC
Controller. This feature is provided to allow user access to IBASIC programs for
short edits or troubleshooting. Several programming modes for developing
IBASIC programs to run on the internal IBASIC Controller are discussed in this
manual.
Secondly, the IBASIC Controller has a dedicated HP-IB interface, select code 8 in
figure 2
, for communicating with the internal instruments of the Test Set. This
HP-IB interface is only available to the IBASIC Controller. There is no external
connector for this HP-IB interface. No external instruments may be added to this
HP-IB interface. The HP-IB interface, select code 7 in
figure 2
, is used to
interface the Test Set to external instruments or to an external controller. The
dedicated HP-IB interface at select code 8 conforms to the IEEE 488.2 Standard
in all respects but one. The difference being that each instrument on the bus does
not have a unique address. The Instrument Control Hardware determines which
instrument is being addressed through the command syntax. Refer to
chapter 4,
"HP-IB Commands"
for a listing of the HP-IB command syntax for the Test Set.