Kv -300 – KEYENCE Visual KV Series User Manual

Page 390

Advertising
background image

9.5 Programming Examples

KV-10/80 Series Only

KV

-300

KV-10/80

Chapter 9 KV-AD4/DA4 Analog I/O Unit

1-366

9

Outputting Analog Input from a Pressure Sensor to an Air Valve

This sample program outputs analog inputs (1 to 5 V) from a pressure sensor to an
air valve (4 to 20 mA).

Conditions

Analog input data is input from analog input V0 on the KV-AD4.
(The digital data of data memory DM0992 is used for this operation.)

The data that was input from analog input V0 is converted, and output to analog
output I0 on the KV-DA4. (The digital data is written to data memory DM0996.)

When the input data in DM0992 is a low value, the output current is decreased.
When input data in DM0992 is a high value, the output current is increased.

Input data 1 V (#2200) in DM0992 is converted to output data 20 mA (#4000) in
DM0996.

Input data 5 V (#3000) in DM0992 is converted to output data 4 mA (#0000) in
DM0996.

Ladder diagram

1. The data of DM0992 is calculated, and the calculation result ((DM0992 - 2200) x

5 mV) is written to DM0000.

2. (4095 - DM0000) is calculated, and the calculation result is written to DM0001.
3. Before the digital data is written to data memory for D/A conversion, check that

the data is #4095 or less.

Note: An unsteady value will be output if a value outside the range 0 to 4095 is
written to data memory for D/A conversion.

4. The output data will be updated at the rising edge of special utility relay 2800. (As

internal relay 1000 switches ON/OFF at each scan, the output data will be
updated every two scans.)

Note 1: "2007" (first scan OFF at power ON) must be set as the input condition. In
the case of analog input, an unsteady value will be input for the first scan when the
power is turned ON.

Note 2: In the case of current output, DM0996 need not be initialized (#2000 written
to DM0996) when the power is turned ON.

2007 DM0992

LDA

#02200

SUB

2002 #04000

LDA

1000

DM0000

SUB

DM0000

STA

DM0001

STA

#00005

MUL

1000

1000

2800

2002

2011

DM0001

LDA

#04095

CMP

DM0001

LDA

DM0996

STA

1

2

3

4

( )

( )

KVHKA Chap 09.p65

08.3.11, 11:20 AM

366

Advertising