I need some help on plc programming

[oister]

PLC help!!!!

Hi,

I need some help on plc. i have been given a ladder logic to make.I have made is but in the end we have to make a little change in it. The parameters are as follows:

Inputs: Start, Stop, Manual and Step
Outputs: Out1, Out2, …, Out8
Relays: Run
Timers: Duration
Sequencer: Seq
0.5s is a half second timer that is activated here.
Now the problem is:
How can you change the circuit so that the sequencing stops when the duration timer has reached 0?

Now what i have to do is change the circuit so that when the timer reduces to zero, all the outputs become deactivated and the sequencing stops until the start button is activated again. I dont know how to solve this now?
any one have some ideas.I also attached the diagram.
Thanks.

 

[oister]

PLC help!!!!

i need help in these too:

A PLC programme that will operate a single set of traffic lights. The lights should be scheduled by three outputs, Red (red light), Amber (amber light) and Green (green light). The sequence should be as follows:

1.Red should be lit for 10 seconds.
2.Red and Amber should then be lit for 3 seconds.
3.Green should then be lit for 10 seconds.
4.Amber should then be lit for 3 seconds.
5.Return to 1.

Design a programme that will operate two traffic lights. One set of lights is to be used to control traffic travelling in the N-S direction at a crossroads and the other set is to control traffic travelling in the E-W direction.

Please suggest me what to do because i have to submit it urgently or some material from where i can understand these.
Thanku