Keithley 6517A, Руководство пользователя

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Front Panel Operation
2-90
Notice that the Model 6517A is reset to BENCH defaults.
With this selection, the electrometer stays armed. Since the
arm source and scan source are set to Immediate, the Model
6517A waits in the measure layer for a trigger.
To run the test and store the readings in the Model 6517A,
press STORE on the electrometer, enter the desired number
of readings (20), and press ENTER. The Model 6517A waits
(with the asterisk annunciator lit) for a Trigger Link trigger
from the Model 7001/7002.
Press STEP on the Model 7001/7002 to start the scan. The
following explanation on operation is referenced to the oper-
ation model shown in Figure 2-70.
Pressing STEP on the Model 7001/7002 takes it out of
the idle state and places operation at point A in the flowchart.
Since the arm layer is programmed for Immediate Spacing,
operation drops down to the scan layer at point A.
Since Scan Trigger Control of the Model 7001/7002 is
set for Source, the scan does not wait at point A for a trigger.
Instead, it bypasses “Wait for Trigger Link Trigger” and pro-
ceeds to point B. Note that this Bypass is in effect only on the
first pass through the model.
Since Channel Trigger Source of the Model 7001/
7002 is also set to Source, the scan does not wait at point B
for a trigger. Instead, it bypasses “Wait for Trigger Link Trig-
ger” and closes the first channel (point C). Note that the By-
pass is in effect only on the first pass through the model.
After the relay settles, the Model 7001/7002 outputs a
Trigger Link trigger pulse (point D). Since the instrument is
programmed to scan ten channels, operation loops back up to
point B, where it waits for an input trigger. Note that Bypass
is no longer in effect.
The trigger pulse from the Model 7001/7002 triggers
the Model 6517A to make a measurement of DUT #1. After
the measurement is complete, the electrometer outputs a
Trigger Link trigger pulse (point E). The trigger applied to
the Model 7001/7002 from the Model 6517A closes the next
channel in the scan, which in turn triggers the electrometer
to measure the next DUT. This process continues until all ten
channels are scanned and measured.
After the last channel is scanned and measured, oper-
ation proceeds to point F, where the Model 7001/7002 out-
puts a trigger pulse. Since the Model 7001/7002 is
programmed to perform two scans, its operation loops back
up to point A, where it waits for an input trigger. Note that
Bypass is no longer in effect.
The trigger pulse from the Model 7001/7002 triggers
the Model 220 to output the next programmed current level.
After the current level is set, the Model 220 outputs a trigger
pulse (point G).
The trigger pulse applied to the Model 7001/7002 from the
Model 230 places operation at point B. The Bypass is again
in effect because this is the beginning of a new scan. This al-
lows operation to drop down to point C, where the first chan-
nel is again closed and eventually measured. As previously
explained, all ten channels are scanned and measured.
After the last channel of the second scan is closed and mea-
sured, the Model 7001/7002 returns to the idle state.
Idle
Bypass
A
Trigger
C
No
Yes
D
Trigger
B
No
Yes
Bypass
F
E
Trigger
Trigger
G
7001or
7002
6517
7001 or
7002
220
7001or 7002
Press STEP
Wait for
Trigger Link
Trigger
Trigger 6517A
to make
Measurement
Trigger 220
to source
next current
level
Wait for
Trigger Link
Trigger
Scan
Channel
Output
Trigger
and Output
Trigger
6517
Scanned
10
Channels
?
Performed
2
Scans
?
Output
Trigger
and Output
Trigger
220
Figure 2-70
Operation model for asynchronous Trigger Link example #2
A
B
C
D
E
F
G