HP 8901B Operation And Calibration Manual page 85

Special k r n c t h Operation
1-21
Capability
To extend instrument
operation
To select the instrument's
additional measurement
capabilities
To access service-related
operation information
Special mnction
Opefation
Most measurements made with the
HP 8901B require only a keystroke
to invoke. There is no need to adjust levels, or select ranges because
the HP 8901Bs microprocessor determines the optimum instrument
settings automatically. However, in some applications it is desirable
to
override the automatic selection. Special functions provide you
with manual control of instrument operation, selection of additional
measurement modes, and the ability to extend measurement ranges.
The HP 8901Bs special functions are described in the following chart.
Codes Application
1
to 10 These specihl functions enable you to select and adjust specific
portions of circuitry within the HP 89018. Use these special
functions to adapt the instrument's operation
to
the special
needs of your application.
These special functions extend the measurement capabilities
of the HP 8901 B by providing additional measurement modes and
functions. Use these special functions to make measurements such as
SINAD, Audio Level, and LO Frequency. You can also use them for
setting limits, setting references, and manipulating calibration data.
These special functions assist in servicing the HP 8901 B by enabling
the instrument to display internal voltages and frequencies. Use these
special functions to verify operation of the HP 8901B.
(Refer to your UP 8907B Service Manual for details on using service
special functions.)
11 to
37
40 to 99
The Special Display
Special function modes are selected first by entering the appropriate code
(prefix, decimal point, suffix) and then pressing the
SPCL
key (lower right
comer
on
the front panel).
1.
Key in 7.2
SPCL.
The
SPCL
key remains lit to indicate that a special
function has been invoked.
2. Now press the
SPCL
key alone. Pressing the
SPCL
key without entering
a number causes the HP 8901B to display which special functions (1-10)
have been set. If you previously entered the
7.2
special function, a 2 should
now appear in the seventh display digit position. The display shows a zero
in each of the other display positions to indicate that these special functions
are still set to their automatic (default) operating condition. Use this capa-
bility to review or verify the special function settings that you have selected.
entering a number causes the instrument to display the special function
setting (1-10) actually being used. (Note that a 2
still
appears in the
seventh display digit position.) The other digits represent the settings
automatically selected for the measurement mode the HP 8901B is
currently in. Use this capability when you are interested in knowing what
settings the instrument is currently using to make
its
measurements.
and return to the previously selected measurement mode.
3.
Press the
SPCL
key
again. Pressing the
SPCL
key twice without
4.
Press the
CLEAR
key to exit the special function display