PLC Ladder Logic Excercise

Thread Starter


Joined Mar 18, 2020
I need to write a ladder logic program that follows this order. I have some work done for this problem on listed problem 14 in the ladder logic picture. Having some trouble piecing it together.

1. A momentary pushbutton is pressed to start the sequence.
2. The light is switched on and remains on for 5 s.
3. The light is then switched off and remains off for 5 s.
4. A counter is incremented by 1 after this sequence.
5. The sequence then repeats for a total of 5 counts.
6. After the fifth count, the sequence will stop and the counter will be reset to zero.


Joined Mar 29, 2021
I'm seeking assistance with this problem as well...
Would you mind sharing the solution to this question?
Feedback would be greatly appreciated!


Joined Mar 29, 2021
What retains and releases input P.B.function ?
That's one of the questions I have trouble figuring out...
Once the input PB is pressed, it suppose to start the sequence and automatically repeat itself until it reaches the desired counter preset value.
And that's the issue I'm having, I can't seem to figure it out..
How can I put on this light with a PB and start a timer?
Then when that timer is done, the light turns off for a specific amount of time.
Afterwards,a counter is incremented by 1, and then it is repeated from the first timer until the counter has reached its desired preset value
Any adjustments I can make from the attached picture I posted earlier?


Joined Jul 18, 2013
What you need is a Initiation rung that registers that the PB has been pressed. this then latches the PB by the 'registration' address AND'ed with the PB.
At present, the PB is acting like a MCR (Master Control Relay) so it requires to be maintained or latched in order for the rest to be powered.
At the end of the process, a completion contact would act momentarily to unlatch the initiation rung, use the end process CTR! ;)