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Sample Programs Appendix B
Scaling
Using the Scaling Functions
Note This function is supported only by the CS1W-AD161, CJ1W-MAD42, and CJ1W-DA08V/08C.
Outline
A pressure sensor is connected to analog input 1 of CJ1W-MAD42. The pressure sensor outputs an analog
signal of between 0 and 20 mA for a pressure between 0 and 500 Pa. Therefore, for a 4 to 20-mA input, a
binary value of 0000 to 01F4 (0 to 500 decimal) in engineering units for the pressure in Pa is directly set using
the MOV instruction. The analog input scaling function of the CJ1W-MAD42 is used here. Therefore, scaling in
the ladder program (using the SCL or other instruction) is not required to convert the values 0000 to 0FA0 of
the resolution to engineering units 0000 to 01F4.
Unit Settings
Program Example
Not Using the Scaling Function
Outline
A/D conversion values are converted according to the linear function calculated from the offset and the values
of
∆X and ∆Y, and retrieved as scaling data.
• The following example uses at resolution of 4,000 and an input signal range of 1 to 5 V where 1 to 5 V is
scaled to 0000 to 0300 (0
°C to 300°C).
Item Setting contents Actual settings
Unit CJ1W-MAD42 ---
Unit number #0 Unit number switch: 00
Input number Input 1 (and output 1) used D20000 = 0011
Input signal range 1 to 5 V/4 to 20 mA D20001 = 0202
Voltage/current range Current: 4 to 20 mA D20035 = 0011
Conversion time/resolution
setting and operation mode
Conversion time: 1 ms, resolution: 4,000
Normal mode
D20018 = 0000
Scaling settings for input 1 Lower limit: 0000 (0000 decimal)
Upper limit: 01F4 (500 decimal)
D20027 (lower limit) = 0000
D20028 (upper limit) 01F4
Disconnection Detection Flag
for analog input 1
200904
The scaled conversion value in engineering
units stored in CIO 2005 is moved to D00000.
MOV (021)
2005
D00000