Rear Panel Familiarization; 3-3-L Connectors And Terminals; Power-Up Procedure - Keithley 776 Instruction Manual

The exponent uses a leading minus to indicate negative
values. The sign on the exponent changes to + for zero
or positive values. The display is also used to indicate
information other than the measurement such as the gate
time or the trigger level.
2. INDICATORS. There are 30 indicators located on
the front panel. The indicators are used to point at a
selected function or signal to the user that the instru-
ment is set to a special function like auto trigger or
remote operation.
33 Rear Panel Familiarization
Figure 3-2 shows the rear panel layout of the model 776.
3-3-l. Connectors and Terminals
1. AC RECEPTACLE. Power is applied_ through the
supplied power cord. to the 3-terminal AC receptacle.
Note that the selected power supply voltage is marked
on the rear panel above the line voltage selector switch.
2. LINE SWITCH. The LINE VOLTAGE SELECTOR
switch selects one of the primary voltage which are
marked on both sides of the switch
3. LINE FUSE. The line fuse provides protection for
the AC power line input. For information on replacing
this fuse. refer to Section 5.
4. IEEE-188 CONNECTOR. This conneclor is used
to connect the instrument to the IEEE-488 bus.
5. TRIGGER LEVEL OUTPUTS. Tbesc three lermi-
nals are used for monitoring. by an external DMM or
oscilloscope. the DC voltage coming from channels A
and B trigger level circuits.
6.
CLOCK. This BNC connector is used to output tbe
internal clock as a reference to another instrument. The
same input may be connected to an external reference.
The function of this input/output is marked above the
connector.
7. EXTERNAL ARMING/GATE/DELAY. A BNC
connector which may receive one of three signals: arm-
ing pulse. external gate signal or external delay pulse.
This input is useful when gate or delay times other then
the internal times are required. or to take one reading
with model 776 in synchronization with other cquip-
ment.
8. CHANNEL A, CHANNEL B, CHANNEL C (Not
shown). These connectors. only present on a Model
776/2.4GIR. are used to connect the "nil to the unknown
signal. Iffront panel connectors are present. they are not
functional.
34. Power-Up Procedure
The basic procedure of powering up the Model
716
is
described below.
Figure 3-2.
Rear Panel Cormecrors and Tenninnls.
3-3