Configuring The Scan Layer - Keithley 2002 User Manual

Front Panel Operation
2.7.3 Configuring the scan layer
The scan layer is used for the following operations:
• To select the scanning event (SOURCE) for the instru-
ment.
• To delay operation in the scan layer.
• To designate the number of scan sequences the instru-
ment will perform (COUNT).
• To enable or disable the Source Bypass.
The scan layer is configured from the SCAN item of the
CONFIGURE TRIGGER menu, which is displayed by
pressing the CONFIG key and then the TRIG key. General
rules for navigating through the menu structure is contained
in paragraph 2.3.4.
SOURCE
This menu item selects the event that controls the scan
source.
IMMEDIATE: With this selection, operation passes imme-
diately into the measure layer.
EXTERNAL: With this selection, external triggers are used
to control the scan source. A trigger stimulus applied to the
Model 2002 passes operation into the measure layer. The
external trigger is applied to the rear panel "EXTERNAL
TRIGGER" BNC connector. See paragraph 2.7.6 for
detailed information on external triggering.
The front panel TRIG key (see MAN-
UAL) is active with external triggering
selected. Pressing the TRIG key passes
operation into the measure layer.
MANUAL: With this selection, the front panel TRIG key
controls the scan source. Operation passes into the measure
layer when the TRIG key is pressed.
The front panel TRIG key is active when
EXTERNAL, GPIB, TRIGLINK, or
TIMER is selected.
GPIB: With this selection, bus triggers control the scan
source. Operation passes immediately into the measure layer
when a bus trigger (GET or *TRG) is received by the Model
2002. See Section 3 for detailed information on bus triggers.
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NOTE
NOTE
The front panel TRIG key (see MAN-
UAL) is active with bus triggering
selected. Pressing the TRIG key passes
operation into the measure layer.
TRIGLINK: With this selection, the scan source is con-
trolled by the Trigger Link of the Model 2002. Trigger Link
is an enhanced trigger system that uses up to six lines to
direct trigger pulses to and from other instruments. Opera-
tion passes into the measure layer when the Model 2002
receives a trigger over the Trigger Link. See paragraph 2.7.7
for details on using the Trigger Link.
The front panel TRIG key (see MAN-
UAL) is active with the Trigger Link
selected. Pressing the TRIG key passes
operation into the measure layer.
After selecting TRIGLINK, you will be prompted to select
an input line and then an output line. Note that you cannot
use the same trigger line for both input and output.
TIMER: Use the timer feature to control the time interval
between scan sequences when scanning. The timer can be set
for an interval from 0.001 seconds (1msec) to 999999.999
seconds with 1msec resolution.
After a scan sequence is triggered to start, the next scan
sequence starts at the end of the programmed timer interval.
If however, the programmed timer interval is shorter than the
time it takes to complete a single scan sequence, the next
scan sequence does not start until the previous one is done.
The front panel TRIG key (see MAN-
UAL) is active with the timer selected.
Pressing the TRIG key after the comple-
tion of a scan sequence starts the next scan
sequence (assuming the Model 2002 is
programmed for another scan sequence;
see COUNT).
HOLD: When HOLD is selected, the scan source is sup-
pressed. As a result, operation does not pass into the measure
layer until HOLD is cancelled by selecting one of the other
scan source selections. Select HOLD from the SELECT
SCAN SOURCE menu by placing the cursor on HOLD and
pressing ENTER. The instrument returns to the SETUP
SCAN LAYER menu.
NOTE
NOTE
NOTE