126 Programmable Logic Controllers: Hardware and Programming
3. Right-click instruction I:0/3 and select
Force
Off. The white
light will turn off and the motors will be in the jog mode. Right-
click instruction I:0/2 and then select
Force
On. The normally
open I:0/2 is forced closed and motor #2 turns on. Right-click
instruction and select
Force
Off. This should turn off motor #2.
0000
0003
0002
0001
Stop Red pushbutton Motor #1
Motor #1
Motor #2
O:0
O:0
I:0 I:0
O:0
0
Temperature
switch
I:0
3
1 0 0
Green
pushbutton
I:0
2
1
End
O:0
2
Stop Red pushbutton
Motor #2
O:0
I:0 I:0
1
Temperature
switch
I:0
3
1 0
Stop
I:0
0
Temperature
switch
I:0
3
Motor #1
O:0
0
Temperature
switch
I:0
3
Figure 6-31. PLC ladder logic diagram for the relay logic diagram shown in Figure 6-29.