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6517B-900-01 Rev. A / Jun 2008
Section 4: Measurement Options
Model 6517B Electrometer User’s Manual
Control sources
With advanced triggering and basic one-shot triggering, operation is controlled by control sources
which hold up operation until the programmed event occurs. Basic one-shot triggering uses one
control source, while advanced triggering uses three control sources. The control sources are
described below.
•
Immediate:
Event detection is immediately satisfied, allowing operation to continue.
•
External
:
Event detection is satisfied when an input trigger via the EXT TRIG IN
connector is received.
•
Manual:
Event detection is satisfied by pressing the TRIG key.
•
GPIB:
Event detection is satisfied when a bus trigger (GET or *TRG) is received.
•
TrigLink:
Event detection is satisfied when an input trigger via the trigger link
connector is received. Not available for basic triggering.
•
TIMER:
Event detection is immediately satisfied on the initial pass through the layer.
Each subsequent detection is satisfied when the programmed timer interval
elapses. Not available in the Arm Layer of the advanced trigger model.
•
Hold:
With this selection, event detection is not satisfied by any of the above control
source events and operation is paused. Not available for basic triggering.
If continuous basic triggering is being used, then operation bypasses the control source (as shown
in
) and performs a device action.
Device action
The primary device action is a measurement. However, the device action could include a function
change and a channel scan (if scanner is enabled). A channel is scanned (closed) before a
measurement is made. When scanning internal channels, the previous channel opens and the
next channel closes (break-before-make). Also included in the device action is the internal settling
time delay for the relay.
Output trigger
After each measurement (device action), an output trigger pulse occurs and is available at the rear
panel of the Model 6517B. When used with an external scanner, each output trigger is used to
select the next channel in a scan (see
Counters
All three layers of the advanced trigger model use programmable counters that allow operation to
return to or stay in the respective layer. For example, programming the measure layer counter to
infinite keeps operation in the measure layer. After each device action, operation loops back to the
trigger layer control source. A counter resets when operation loops back to a higher layer (or idle).
Bench default setup
The bench default setup selects advanced triggering and takes the Model 6517B out of idle, sets
the control sources of all layers to Immediate, and sets the measure layer counter to infinite. With
this trigger model setup, operation simply falls into the measure layer (and stays there) to make
continuous measurements.
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