Keithley 2750 User Manual

D-6 Signal Processing Sequence and Data Flow Model 2750 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 calcu-
lation. 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
2750-900-01.book Page 6 Wednesday, August 3, 2011 7:56 AM

Keithley 2750 Specifications

General

Interface	GPIB, RS-232, Ethernet
Switching Speed	Up to 500 channels/second
Maximum Voltage	300V
Operating Temperature	0°C to 50°C
Measurement Functions	DCV, ACV, DCI, ACI, 2-wire Resistance, 4-wire Resistance, Frequency, Temperature
Resolution	6.5 digits
Current	1A
Maximum Current	1A