Mitsubishi Electronics 13JW55 ユーザーズマニュアル

 

 

App. - 1

 

 

APPENDIX 

Appendix 1    I/O Control Mode 

The CPU supports two types of I/O control modes; the direct mode and refresh 

mode. 

 

Appendix 1.1  Direct mode 

In the direct mode, input signals are imported to a programmable controller every 

time they are input and treated as input information. The operation results of a 

program are output to the output data memory and the output modules. The 

following diagram shows the flow of I/O data in the direct mode. 

 

Data memory for inputs (X)

Test operation using peripheral device
Link refresh of MELSECNET/H
Writing from serial communication 
modules, etc.

Data memory for outputs (Y)

Executing the OUT instruction in the 
sequence program
Test operation using peripheral device
Writing from serial communication 
modules, etc.

Programmable controller

CPU
(Operation processing)

Input 
module

Output 
module

Y70

X0

Y75

1)

2)

3)

4)

5)

 

 

• When the input contact instruction is executed:   

An OR operation is executed in the input information 1) from the input module and 

input information 2) in the data memory. Then the result is used as input 

information 3) at sequence program execution. 

• When the output contact instruction is executed:   

Output information 4) is read from the data memory for output (Y), and a sequence 

program is executed. 

• When the output OUT instruction is executed:   

The operation result 5) of the sequence program is output to the output module, 

and is stored in the data memory for output (Y). 

• When the QCPU executes I/O in the direct mode, a sequence program uses DX 

for inputs and DY for outputs.