Front Panel Description

Front Panel
Description
Figure 3-1 shows the brief description of each key on the 4285A's
front panel.
Figure 3-1. Front Panel Overview
1 LINE On/O
Power on/o switch. In the ON position all operating voltages are
applied to the instrument. In the OFF position NO operating voltages
are applied to the instrument.
2 LCD Panel
The Liquid Crystal Display (lcd) displays measurement results, test
conditions, softkey labels, and other information.
3 SOFTKEYs
Five softkeys are used to select control and parameter functions.
Each softkey has a softkey label along its left side.
4 MENU Keys
Menu selection keys. There are three menu keys, 4DISPLAY FORMAT5,
4MEAS SETUP5, and 4CATALOG/SYSTEM5. The menu keys are used to
access the corresponding selection of instrument functions.
3-2
Overview
5 CURSOR Keys
The CURSOR arrow keys are used to move the eld select cursor from
eld to eld on the LCD display page. When the cursor is moved to a
eld the eld changes to an inverse video image of the original eld.
The cursor can only be moved to a eld, it can't be moved into a
monitor area.
6 ENTRY Keys
The ENTRY keys are used to enter numeric data into the 4285A. The
ENTRY keys are composed of the digits 405 to 495, a period 4.5, a minus
sign 4-5, 4ENTER5, and 4BACK SPACE5 keys. 4ENTER5 terminates numeric
input data and enters the displayed value on the Input line (second
line from the bottom of the LCD screen). 4BACK SPACE5 deletes one last
character of the input value.
7 GPIB Status Indicator
The GPIB status indicators consist of the RMT (remote), TLK (talk),
LTN (listen), and SRQ (service request) indicators. These indicators
are used to show the 4285's GPIB status when it is interfaced to a
controller via GPIB.
8
4LCL5
9
4TRIGGER5
Key
The Local (LCL) key returns the 4285A to local (front-panel) operation
from the remote (computer controlled) operation state unless a Local
Lockout command has been invoked from the computer. 4LCL5 is the
only front-panel key activated while the 4285A is in the REMOTE
state.
Key
This key is used to manually trigger the 4285A when it is set to the
Manual Trigger mode.
A MEMORY Card Slot and UNLOCK Button
The MEMORY card slot is where you insert the memory cards. The
UNLOCK button is used to eject a memory card.
B
4DC
BIAS5
Key
4DC BIAS5 is used to enable or to disable the DC bias output. 4DC BIAS5
is a toggle type switch, and the DC BIAS ON/OFF LED indicator is
located above 4DC BIAS5. There are two ways to apply the DC bias
to the DUT. One is Option 001 DC bias option and the other is the
42841A Bias Current Source combined with the 42842C Bias Current
Test Fixture. Either one can be selected in the CONFIG eld. 4DC BIAS5
simply the DC bias output turns ON or OFF, and the DC bias value
must be set in the BIAS eld.
C CONTRAST Control Knob
This knob is used to adjust the LCD's CONTRAST.
Overview
3-3
D
UNKNOWN Terminals
These are the UNKNOWN terminals used to connect a four-terminal
pair test xture or test leads for measuring the DUT.Available four
terminal-pair test xtures or test leads are refer to the Accessories
Selection Guide For Impedance Measurements (Catalog number
5963-6834E).
INSTALLATION CATEGORY I
E FRAME Terminal
This Terminal is tied to the instrument's chassis and can be used for
measurements that require guarding.
3-4
Overview
Rear Panel
Description
Figure 3-2 gives a brief description of the 4285A's rear panel.
Figure 3-2. Rear Panel Overview
1 GPIB Interface Connector
The GPIB interface connector allows interfacing with a controller and
other GPIB instruments.
2 Interface Connectors
When interface options are installed, the interface connectors will be
installed as shown in Figure 3-2. When the 4285A is not equipped
with an interface option, blank covers are installed.
3 INT DC BIAS MONITOR Connector
This BNC connector is used for monitoring the DC bias voltage or
current applied to the DUT. The monitor function can be switched to
either voltage ( V BIAS ) or current ( I BIAS ) on the MON eld in the
MEAS SETUP page. This connector is installed only when Option 001
is installed.
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4 EXT TRIGGER Connector
The 4285A is triggered by inputting a TTL active low to high going
edge trigger pulse.
Overview
3-5
5 LINE Input Receptacle
AC power cord receptacle.
6
LINE Fuse Holder
Fuse holder for the 4285A's line fuse. Refer to Figure 2-3 to
determine the correct line fuse rating.
7 LINE VOLTAGE SELECTOR
The switch used to match the 4285A to the AC operating voltage
being used. Refer to \Line Voltage Selection" in Chapter 2 to
determine the correct operating voltage.
3-6
Overview