LG Electronics 120S user manual 4000

Chapter 7 Usage of Various Functions

3) Parameter setting

(1) Scaling function

This function convert automatically range when the inout/output range is not matched.

In case that input/output is current , this function is useful that external equapment’ range is not matched each other. (MASTER-K120S series converts range automatically as following : 0 ~ 20mA ⇔ 4 ~ 20mA)

4000				4000
				800
0				0
0 ㎃		20 ㎃		-1000	4 ㎃	20 ㎃
Resolution :	20	㎃/4000 = 5
			㎂
				Resolution :		20 ㎃/3200 = 6.25 ㎂

Conversion method is as below

•scaling conversion value (A/D conversion) = [(data of 0 ~ 20 ㎃) – 800] x 4000/3200 example) in case of 8 ㎃ input at range 0 ~ 20 ㎃

before the scaling conversion : 8 ㎃ / 5 ㎂ = 1600

after the scaling conversion : (1600 –800) x 1.25 = 1000

• scaling conversion value (D/A conversion) = [(data of 4 ~ 20 ㎃) x 3200/4000] + 800 example) in case of ‘1000’ output at range 4 ~ 20 ㎃

current output value before the scaling conversion : 1000 x 5 ㎂ = 5 ㎃

current output value after the scaling conversion : (1000 x 0.8) + 800 = 1600 1600 x 5 ㎂ = 8 ㎃

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