Rockwell Automation 44887-PUB, 44887 Enwatch - Manual (Page 29)

Publication GMSI10-UM031C-EN-E - January 2009
Installing the Enwatch 25
Setting Up Sample Measurements
This section gives examples of setting up measurement definitions in
Emonitor.
DC or other Numeric measurements
Suppose you have a transducer with an output of -2 V to 2 V and a linear scale
from -10° F to 100° F. How do you set up the transducer in Emonitor?
If the volts reading is R, then the data stored in Emonitor is:
(R / calibration + DC offset)
Input range volts: (X, Y)
Scale value: (A, B) volts
Data in Emonitor = (R - X) x ((B-A) / (Y-X)) + A
Calibration value in transducer setup: [(Y-X) x 1000mv / eu]/(B-A)
DC Offset in transducer setup: A - (B-A) x X / (Y-X)
In Emonitor, select Setup>Calibration and set up the calibration for the
Temperature transducer.
EXAMPLE
Input range: (-1.31 V, +0.87 V)
Scale value: (100° F, 200° F)
Calibration: [(0.87 - (-1.31)) x 1000] / (200 - 100) = 21.8
Offset: 100 - (200 - 100) x (-1.31) / (0.87-(-1.31)) = 160.09
Input type should be DC coupled and the jumper setting
on board needs to be set as DC couple as well.