Industrial Applications
◾
397
Closing door. The door closes automatically after 30 s. The door can
also close manually before
the completion time of 30 s, by momentary pressing of button b
1
. The indication light H
0
turns on either during the door movement or by being in the open state.
Emergency actions. If during the door closes,
the photocell PC is activated, the door stops
immediately, while the door continues to close if the photocell is deactivated. The move-
ment of the door, either opening or closing, is interrupted permanently by the pressing of
emergency button b
2
.
After making a diagram of the I/O device connections to a PLC, write the required program.
Do'stlaringiz bilan baham: