Front Panel Operation
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SOURCE: This menu item selects the event that controls the
scan source.
IMMEDIATE: With this selection, operation passes immedi-
ately into the measure layer.
EXTERNAL: With this selection, external triggers are used
to control the scan source. A trigger stimulus applied to the
Model 6517A passes operation into the measure layer. The
external trigger is applied to the rear panel “EXTERNAL
TRIGGER” BNC connector. See paragraph 2.15.4 for de-
tailed information on external triggering.
NOTE
The front panel TRIG key (see MANU-
AL) is active with external triggering se-
lected. 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.
NOTE
The front panel TRIG key is active when
EXTERNAL, GPIB, TRIGLINK, or TIM-
ER 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
6517A. See Section 3 for detailed information on bus trig-
gers.
NOTE
The front panel TRIG key (see MANU-
AL) 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 6517A. Trigger
Link is an enhanced trigger system that uses up to six lines
to direct trigger pulses to and from other instruments. Oper-
ation passes into the measure layer when the Model 6517A
receives a trigger over the Trigger Link. See paragraph
2.15.5 for details on using the Trigger Link.
NOTE
The front panel TRIG key (see MANU-
AL) is active with the Trigger Link select-
ed. 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 be-
tween scan sequences when scanning. The timer can be set
for an interval from 0.001 seconds (1msec) to 999999.999
seconds with 1msec resolution.
The first scan sequence occurs immediately, while all subse-
quent scans start 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, the next scan will
not start until the previous one is done.
NOTE
The front panel TRIG key (see MANU-
AL) 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 6517A 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.
DELAY
This delay is used to hold up operation in the scan layer. Af-
ter the scan event occurs, the instrument waits until the delay
period times out (0 to 999999.999 sec.) before proceeding to
the measure layer.
COUNT
This menu item defines the number of times operation re-
turns to the scan layer.
INFINITE: Use this selection to continuously return opera-
tion to the scan layer.
