Chapter 1 Introduction 1-3
1.3.1 Voltage input
The A/D module converts the analog input from external devices to the digital value that
can be handled by CPU module.
When the analog input is voltage input, the K4F-AD3A and K7F-AD3A has two input
ranges such as 1 ~ 5VDC and 0 ~ 10VDC. The K3F-AD2A has three input range such as
1 ~ 5VDC, 0 ~ 10VDC, and –10 ~ 10VDC.
With all analog input range, the digital output is varied in the range of 0 ~ 4000. Therefore,
the resolution of the A/D module is obtained by following equation;
1) 1 ~ 5VDC range
When the A/D module operates with 1 ~ 5VDC range, the 1VDC analog input is
converted to digital 0, and the 5VDC analog input is converted into digital output 4000.
Therefore, the resolution per 1 digital value is 0.001VDC.
Figure 1.3 A/D conversion characteristics ( 1 ~ 5VDC )
2000
2001
2002
1998
1999
3.000V
3.001V
2.999V
3.002V
2.998V
4000
2000
03V
5V
Analog input voltage
Digital output value
1V