Eaton ELCM Series, Руководство по эксплуатации

Страница: 122 / 336

3. AIAO Units
MN05003006E F or more information visit:
w w w. e a t o n . c o m
1-15
4. Program description
y
When the ELC goes from STOP to RUN, set CH1 to current input mode (mode 3),
and set the number of samples for the average value of the input signals for CH1 to
10.
y
Save the average value of the input signals in D40 and the present value of the input
signals in D50.
y
In current loop mode, The value range for 0 ~ 20mA is K0 ~ K4,000. D50 is 200 times
of the actual current value (i.e. 4,000/20 = 200). Divide the value in D50 by 200 and
store the value obtained into D0 which will be the actual value of the present
measured current.
5. Program example
Ladder diagram: Explanation:
Set CH1 to mode 3 (current
input mode)
Set the number of samples for
averaging to 10 for CH1.
Store the average value of CH1
input signals into D40
Store the present value of CH1
input signal into D50
M1002
M1000
K0 K1 TO
K0 K6 K1
K0 K12 K1
K0 K1 TO
K200
F RO M
DIV
H3
K10
D40
D50 D0
K1
K2
F RO M
D50
D0 is the actual value of the
present measured current at
CH1
3.1.2 ELC-AN02NANN / ELC-AN04NANN Analog Output Modules
3.1.2.1 The D/A Conversion
The most frequently used analog signals in Industrial applications are 0 ~ 10VDC and current 0
~ 20mA. The analog output modules discussed in this chapter support these analog signals for
controlling analog devices. These signals are represented by the same decimal range in the ELC
controllers: 0 ~ 4,000.
3.1.2.2 Introduction
The analog output modules ELC-AN02NANN and ELC-AN04NANN are configured and
controlled by an ELC controller or a Modbus master device. When using these analog output
modules with an ELC controller the FROM / TO instructions are used to configure and control
these modules. The analog output module receives 12-bit digital data from the ELC controller
and converts it to an analog output signal (voltage or current). There are 49 CR (Control Register)
in each module and each register is 16 bits in length.