KEYENCE Visual KV Series - Manual (Page 383)

9.5 Programming Examples KV-10/80 Series Only
KV
-300
KV-10/80
Chapter 9 KV-AD4/DA4 Analog I/O Unit
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9.5 Programming Examples
This section describes sample programs for the KV-AD4/DA4. Refer to this section
when making programs for the KV-AD4/DA4.
Calculating Analog Data Values from Digital Data
This sample program reads A/D-converted digital data from memory, and calculates
the value of the actual analog-input voltage.
Conditions
• The analog input data from analog input V0 on the KV-AD4 is calculated.
(The digital data of data memory DM0992 is used for this operation.)
• When the calculated value is a positive value, an absolute value is written to
memory DM0100, and when the calculated value is a negative value, an absolute
value is written to memory DM0101. Data is written in mV units.
For example:
When the input is +10 V, "10000" (data x 1000) will be written to DM0100.
When the input is - 10 V, "10000" (data x 1000) will be written to DM0101.
Ladder diagram
1. The data of DM0992 is calculated, and the calculation result (data x 5 mV -
10000) is written to DM0000.
2. The KV-AD4 judges that the DM0000 data is positive or negative by comparing
DM0000 with $8000. (When the MSB of DM0000 is OFF, the data is judged to
be positive, and when it is ON, the data is judged to be negative.)
3. If the data is a positive value, the calculation result is written to DM0100.
4. If the data is a negative value, the 2’s complement of the data is calculated to
change its sign to a positive sign, and the result is written to DM0101.
Note: "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.
DM0000
LDA
2007
2009
2009
DM0000
LDA
DM0992
LDA
$8000
CMP
#00005
MUL
DM0000
STA
DM0000
LDA
COM
DM0100
STA
DM0101
STA
#00001
ADD
#10000
SUB
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