Omega i-SERIES User Manual page 35

Scaling:
Y2
Y1
b
To remap 4 – 20 mA to a displayed reading from 0 to 100 then use slope:
Rd2 – Rd1
Slope (Scale) = -------------------
In2 – In1I
where: Rd2 – Hi Display reading (100), Rd1 – Low Display reading (0)
In2 – Hi Input (20 x 500),
1. Obtain a Scale Factor
Scale = (100-0) / (9999-2000) = 0.0125016
2. Rewrite the Scale Factor as an integer times an exponent
0.0125016 = 125016 E -7
3. Then Encode these values
125016 Dec = 1E858 Hex - Reading Scale Data
(RDGSC.18 ~ 0 value stored into bits 0 - 18);
E –7 is represented as RDGSC.23 ~ 20 = 8 (DP = 7);
Direct Scale is represented as RDGSC.19 = 0 (direct scale);
X1 X2
In1 – Low Input (4 x 500)
Y = mX + b
WHERE: m - SLOPE (SCALE)
b - OFFSET
(Y2 - Y1)
m =
(X2 - X1)
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