Keithley 2182, User Manual, Page: 104 / 339

5-14 Ratio and Delta
Model 2182 and SourceMeter trigger synchronization
The timing diagram in Figure 5-4 shows trigger synchronization between the SourceMeter
and the Model 2182 for a 2-point custom sweep. As shown in the timing diagram, the
SourceMeter will output a trigger after every source sweep point, and the Model 2182 will
output a trigger after every A/D conversion.
Figure 5-4
Triggering timing diagram
When the TRIG key on the SourceMeter is pressed, it starts the sweep (o1mA) and
triggers the Model 2182 to start a Delta measurement. After the delay period, the Model 2182
performs an A/D conversion for the V1t1 phase of the Delta measurement, and then triggers the
SourceMeter to output the second point of the sweep (-1mA). At this point, the Model 2182 does
not wait for the return trigger from the SourceMeter to perform the V1t2 phase of the Delta
measurement. That second trigger from the SourceMeter is ignored. After the A/D conversion
for the V1t2 phase, the Delta reading is calculated and displayed.
If programmed for another sweep, the trigger from the Model 2182 to the SourceMeter will
again start the sweep to perform another Delta measurement.
P0000
A/D Conversion
V1t1
Delay A/D Conversion
V1t2
Delay A/D Conversion
V1t1
Delay
2182 Delta Measurements
2182 VMC
...
...
SourceMeter Output
SourceMeter TRIG OUT
...
...
–1mA
+1mA
P0000
P0001
One Delta Measurement
Press TRIG Ignored by 2182 Ignored by 2182
Delta reading available
on second VMC