HP (Hewlett-Packard) HP 85660B ユーザーズマニュアル
A5 Front Panel, Circuit Description
The A5 Front Panel comprises the
Keyboard,
Rotary Pulse Generator (RPG),
Instrument Check indicator
LINE power switch, STANDBY power indicator LED, and
CAL OUTPUT connector and cable. The RF INPUT,
LO OUTPUT, and 321.4 MHz
IF INPUT and IF OUTPUT connectors are physically part of the A6 RF Module and are
described in detail in that section.
Keyboard
Keyboard includes the 49 pushbutton switches and 9 associated indicator
on the
RF Section front panel.
Keyboard Switches
Each of the normally open SPST switches consists of a spring-loaded contact and a pair
of printed-circuit board contacts. All but two of the keyboard switches are organized in a
matrix of rows and columns. When a front-panel key is pressed, the corresponding SPST
switch is closed, connecting a normally grounded key row to a key column. The grounded
key column signal is detected on the Al2 Front Panel Interface,
of printed-circuit board contacts. All but two of the keyboard switches are organized in a
matrix of rows and columns. When a front-panel key is pressed, the corresponding SPST
switch is closed, connecting a normally grounded key row to a key column. The grounded
key column signal is detected on the Al2 Front Panel Interface,
the Al5 Controller
to immediately halt the sweep. Then, the Al5 Controller polls (grounds) each of the key
rows sequentially (starting with key row 0) to identify the particular front panel key that is
pressed. During normal operation, the front-panel SWEEP LED can be observed to blink off
momentarily as the Al5 Controller halts the sweep, polls both the IF Section keyboard and
the RF Section keyboard, and then reacquires phaselock before continuing on with the sweep.
rows sequentially (starting with key row 0) to identify the particular front panel key that is
pressed. During normal operation, the front-panel SWEEP LED can be observed to blink off
momentarily as the Al5 Controller halts the sweep, polls both the IF Section keyboard and
the RF Section keyboard, and then reacquires phaselock before continuing on with the sweep.
Indicator
The nine keyboard indicator
and the two INSTR CHECK indicator
are lighted
selectively by the Al5 Controller to indicate the state of coupled functions, SIGNAL TRACK
(on/off), DATA entry (enabled/disabled), HP-IB control status (remote and addressed), and
self-test. U2 and U3 latch the LED data from the Data Bus. All front-panel
(on/off), DATA entry (enabled/disabled), HP-IB control status (remote and addressed), and
self-test. U2 and U3 latch the LED data from the Data Bus. All front-panel
are lighted
momentarily during the turn-on self test for verification.
The two INSTR CHECK indicator
are lighted selectively by the Al5 Controller to
indicate the overall results of the most recent instrument self test. An instrument self test is
performed each time the LINE switch is switched to ON or the
performed each time the LINE switch is switched to ON or the
PRESET
]
key is pressed.
Both
are lighted at the start of each self test, and both are turned off upon successful
test completion; if one or both of the INSTR CHECK
remain on, an instrument fault
has been detected. Refer to the Al5 Controller section for detailed information about the self
test.
test.
A5 1