KEYENCE Visual KV Series - Manual (Page 374)

9.4 Programming KV-10/80 Series Only
KV
-300
KV-10/80
Chapter 9 KV-AD4/DA4 Analog I/O Unit 1-350
9
9.4 Programming
9.4.1 Programming the KV-AD4
This section describes the A/D conversion mechanism, and the digital data that is
written to the CPU by the KV-AD4 after A/D conversion. It also describes how to
calculate actual voltage and current values based upon the digital data written to
CPU.
A/D Conversion Mechanism
This item describes the A/D conversion mechanism on the KV-AD4. Check this item
before writing sequence programs for the KV-AD4.
1. The analog signal (voltage or current) is input to the KV-AD4 from the external
instrument.
•
This operation is called "analog input."
2. The KV-AD4 converts the analog signal to digital data.
• This operation is called "A/D conversion."
3. The KV-AD4 then writes the digital data to the data memory for A/D conversion
on the CPU.
•
Digital data is automatically written at each scan.
➮ For details, see "About Digital Data after A/D Conversion" on the next page.
4. If necessary, the digital data is processed by the sequence program on the CPU.
• The value of the actual input voltage or current can be calculated from the
digital data.
➮ For details, see "Calculating Voltage and Current Values from Digital Data"on page 1-352.
The calculated values can be used for further processing besides the sequence program.
• The digital data can also be output as analog data as it is.
Power
supply
unit
A/D
converter
KV-AD4 CPU
Writing digital data
Sequence
program
Data memory for
A/D conversion
Analog
input Transducer
or
pre-amp
External
instrument
(e.g. sensor)
1
2
3
4
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