E L C O p e r a t i o n M a n u a l
F o r m o r e i nf o r m a t i o n v i sit :
w w w. e a t o n . c o m
MN05003006E
1-12
The chart above is for adjusting A/D conversion characteristic curves for the voltage input
mode and current input mode. Users can adjust the conversion characteristic curve by
changing OFFSET values (CR#18~CR#21) and GAIN values (CR#24~CR#27) depending on
the application.
LSB (Least Significant Bit):
1.
Voltage input: 1LSB=10V/8,000=1.25mV.
2.
current input: 1LSB=20mA/4,000=5
μ
A.
Adjusting A/D Conversion Curve in Voltage Input Mode
1. Description
y
Take ELC-AN04ANNN for example. When CR#1 is set as voltage input mode (mode
0), the OFFSET value will be set as 0V (K0) and GAIN value as 5V (K4,000), i.e.
input voltage -10V ~ +10V will correspond to values -8,000 ~ +8,000.
y
When CR#1 is set to voltage input mode (mode 1), the OFFSET value will be set as
2V (K1,600) and GAIN value as 6V (K4,800), i.e. input voltage -6V ~ +10V will
correspond to values -8,000 ~ +8,000.
y
If you cannot use the default voltage input mode (mode 0 and mode 1), you can
make adjustments on the A/D conversion curve according to your actual needs. For
example, Set the OFFSET of CH1 ~ CH4 to 0V (K0) and GAIN to 2.5V (K2,000).
y
You only need to set up the A/D conversion curve once. Then set up CR#33
(OFFSET/GAIN tuning authorization) to prevent these values from being changed..
2. Devices
y
X0 = On: Configure the input mode for the analog inputs at CH1 ~ CH4 to mode 1.
y
X1 = On: Set the OFFSET values of CH1 ~ CH4 to 0V (K0) and the GAIN value to
2.5V (K2,000).
y
M0 = On: Disable the ability to modify the offset and gain.
3. Program
explanation
y
When X0 = On, set CR#1 to K585 (H’249, i.e. 0000 0010 0100 1001 in binary) and
the signal input mode at CH1 ~ CH4 as mode 1 (-6VDC – 10VDC voltage input
mode).
y
When X1 = On, write K0 (OFFSET value of CH1 ~ CH4) into CR#18 ~ 21 and K2,000
(GAIN value of CH1 ~ CH4) into CR#24 ~ 27.
y
When X1 goes from On to Off, set M0 = On to disable modifying the Gain and Offset.
Write K585 (H’249, i.e. 0000 0010 0100 1001 in binary) into CR#33.
