Mitsubishi 00JCPU User Manual page 383

9.2.1 Input (X)
(1) Definition
The input (X) is used to send commands or data to the CPU module from external devices such as push-button
switches, selector switches, limit switches, and digital switches.
(2) Concept of input (X)
One input point is assumed to be a virtual relay Xn in the CPU module.
Programs use the normally open or closed contact of Xn.
PB1
LS2
PB16
Input ladder (external device)
(3) Allowable number of normally open or closed contacts
There are no restrictions on the number of normally open or closed contacts of Xn used in a program, as long as
the program capacity is not exceeded.
No restrictions on
the quantity used.
Push-button switch
Selector switch
Digital switch
1 2 3
Figure 9.2 Commands from external devices to a CPU module
Virtual relay
X0
X0
X1
X1
XF
XF
Figure 9.3 Concept of input (X)
X0
X0
Y21
X0
Figure 9.4 Input (X) used in a program
Input (X)
Sequence
operation
Program
X2
X1 X2
CHAPTER9 DEVICES
Programmable
controller
Y20
Y21
Y23
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