Eaton ELCM Series, Operation Manual

Page: 120 / 336

3. AIAO Units
MN05003006E F or more information visit:
w w w. e a t o n . c o m
1-13
4. Program example
Ladder diagram: Explanation:
Set CH1 ~ CH4 as mode 1
(voltage input mode)
Set the OFFSET value of
CH1 ~ CH4
Set the GAIN value of CH1 ~
CH4
Disable modifying the Gain
and Offset
X0
M0
X1
K0 K24 K4
K0 K33 K1
K0
K1 TO P
K0 K4
M0
TO P
TO P
TO P
X1
SET
H249
K0
K2000
H249
K1
K18
„
Adjusting A/D Conversion Curve in Current Input Mode
1. Description
y
For this example use the ELC-AN04ANNN analog input module. When CR#1 is set
for current input mode (mode 2), the OFFSET value will be set to 4mA (K800) and
the GAIN value as 20mA (K4,000), i.e. input current -12mA ~ +12mA will correspond
to values -4,000 ~ +4,000.
y
When CR#1 is set to current input mode (mode 3), the OFFSET value will be set to
0mA (K0) and GAIN value as 20mA (K4,000), i.e. input current -20mA ~ +20mA will
correspond to values -4,000 ~ +4,000.
y
If you cannot use the default current input mode (mode 2 and mode 3), you can
make adjustments on the A/D conversion curve according to your actual needs. For
example, Set the OFFSET of CH1 ~ CH4 to 5mA (K1,000) and GAIN to 20mA
(K4,000).
y
You only need to set up the A/D conversion curve once. Set up CR#33
(OFFSET/GAIN tuning authorization) to prevent modifying the Gain and Offset
values.
2. Devices
y
X0 = On: Set the input mode of the signals at CH1 ~ CH4 to mode 3.
y
X1 = On: Set the OFFSET values of CH1 ~ CH4 to 5mA (K1,000) and the GAIN
value to 20mA (K4,000).
y
M0 = On: Disable modifying the Gain and Offset values.
3. Program description
y
When X0 = On, set CR#1 to K1755 (H’6DB, i.e. 0000 0110 1101 1011 in binary) and
the signal input mode for CH1 ~ CH4 as mode 3 (current input mode).
y
When X1 = On, write K1,000 (OFFSET value of CH1 ~ CH4) into CR#18 ~ 21 and