Omron CQM1H series - Page 137

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If the following DM settings are made, the scaling as shown in the following
graph will be performed.
In this example, BCD data between 0 to 1000 will be scaled in order to output a
current of 4 to 20 mA.
Polygonal coordinate points and parameter data format
(Refer to the Analog Output Unit Operation Manual for details.)
DM 0100
DM 0101
DM 0102
DM 0103
DM 0104
4000
03E8
019A
03E8
07FF
(Hexadecimal)→
(Hexadecimal)→ (1) X axis maximum value
(Hexadecimal)→ (2) Y axis intersection
(Hexadecimal)→
(Hexadecimal)→
Coordinate of (3)
0
07FF
(20 mA)
(2) 019A
(4 mA)
(3)
1000 (1)
(03E8 hexadecimal)
Value of DM 0000
(Input data)
(BCD)
Output data (hexadecimal)
It is possible to convert data into a polygonal line as shown below. Refer to the
linear approximation description for ARITHMETIC PROCESS – APR(––) in
Section 5 of the CQM1/CPM1 Programming Manual (W228) for details.
It is not possible to use the APR instruction to obtain negative output (2’s com-
plement). If required, execute the APR instruction in a positive range and con-
vert it to negative output using a program. The following is an example of a pro-
gram that converts data in a range of 0000 to 0FFF to data in a range of 8000 to
07FF.
* “n” indicates the allocated word for analog output 1.
Input condition
CMP(20)
#0800
APR result
ORW(35)
#F800
APR result
n
MOV(21)
APR result
n
25505 (> flag)
25505 (> flag)
Programming and Adjustment
Section 3-3