Keithley 2700 - Signal Processing Using Ratio or Ch Avg

D-6 Signal Processing Sequence and Data Flow Model 2700 Multimeter/Switch System User’s Manual
Signal processing using Ratio or Ch Avg
With a switching module installed, the ratio or average of two channels can be calculated.
Figure D-3 shows where Ratio or Ch Avg is calculated in the signal processing sequence.
Figure D-3
Signal processing using Ratio or Channel Average
With a channel closed, and Ratio or Ch Avg enabled, the reading that is applied to the
“Ratio or Ch Avg” block in the flow chart is used as the Chan A value for the calculation.
The paired-channel then closes, and that reading is used as the Chan B value for the
calculation. Ratio or Ch Avg is then calculated as shown in
Figure D-3.
As shown, the result of Ratio or Ch Avg can then be used by an enabled Math operation.
NOTE For details on these calculations, see “Ratio and channel average,” page 5-16.
Input Signals
Rel
Math
(mX+b,
Percent
Limits
Filter
Buffer
Display
Reading
Recall
A/D
Conversion
Process
Chan A Chan B
Ratio
or
Ch Avg
Ratio = Chan A / Chan B
Ch Avg = (Chan A + Chan B) / 2
Rel’ed reading = Reading - Rel Value
Y = mX + b
Percent = ————––—
X - Reference
Reference
100%
Reciprocal = 1/ X
Store
Ratio or
Channel Average
Calculation
Output Trigger Pulse (VMC)
Moving or Repeating
Signal
Conditioning