Keithley 2182, Quick Reference Manual, Page: 26 / 30

20 Quick Reference Guide
Programming example
The command sequence in Table 12 enables Ratio and displays the result on the computer
CRT.
mX+b
This math operation manipulates normal display readings (X) mathematically according
to the following calculation:
Y = mX+b
where: X is the normal display reading
m and b are user-entered constants for scale factor and offset
Y is the displayed result
To configure and enable mX + b, press SHIFT and then MX+B to display the present scale
factor. Enter the desired M, B, and UNITS values at the prompts, and press ENTER. The
MATH annunciator will turn on to indicate that mX+b is enabled. Press SHIFT then
MX+B again to disable the function. The MATH annunciator will turn off.
Percent (%)
This math function determines percent deviation from a specified reference value. The
percent calculation is performed as follows:
Input – Reference
Percent = ––––––––––––––––– × 100%
Reference
where: Input is the normal display reading
Reference is the user entered constant
Percent is the displayed result
To configure and enable the percent function, press SHIFT then %. Enter the desired REF
value, then press ENTER. The MATH annunciator will turn on to indicate that percent is
enabled. Press SHIFT then % again to disable the function. The MATH annunciator will
turn off.
Table 12
Command sequence for ratio measurement example
Command* Comments
:SENS:FUNC ‘VOLT’ Select voltage function.
:SENS:CHAN 1 Select channel 1 for range control.
:SENS:VOLT:RATIO ON Enable ratio function.
:READ? Trigger and request reading.
*Model 2182 must be addressed to talk after sending :READ? to acquire reading.