Mitsubishi MELSEC System Q Manual page 108

Programming PLC Applications
b Controlling the motor
At the end of the program the signal states of the local variables for opening and closing are
transferred to outputs Y11 and Y12.
b Warning lamp: "Gate in Motion" and "Gate in Undefined Position"
If neither of the limit switches is activated this means that the gate is being opened or closed or
has been stopped in an intermediate position. In all these situations the warning lamp blinks.
The blink speed is controlled with special relay SM412, which is automatically set and reset at
1s intervals (see chapter 5.2). SM412 is assigned as Global Variable when entering the
program:
Enter SM412 into the Address field of the Variable Selection window. Then click on Define .
The illustration on the next page shows the entire Ladder Diagram for the control of the rolling
shutter gate.
4 – 44
An Introduction to Programming
After entering the variable name _1_second_clock
the message shown on the left appears because
this variable doesn't exist yet. Click on Define
global .
MITSUBISHI ELECTRIC