traffic light again

got ask a question of traffic light of logixpro,I talked one engineer today, he gave me a pratice for my better career development,BTW, thanks everyone for answer my question,appreciate!!

for the traffic light, he wanna do the requirement like:

from the bottom left to the top right road is main road,the main road will usually have a green light.If a vehicle triggers the in-pavement sensor on the secondary road,(as long as the main road has been green for at least 12 seconds), the main road will have 4 seconds of amber, and then turn red. there will be 1 second both sides red lights overlap, and then the secondary will be green for 10 seconds, the secondary should also have a 4 seconds amber and 1second overlap.
pedestrian crossing lights for the main road will show walk when the light is green, flsh when amber and be off when is red. The pedestrian crossing light for the secondary road will be actuated by pressing the appropriate button. If the secondary light is red when the button is pressed, the lights will cycle as described for the in-pavement vehicle sensor above. If the light is green when the button is pressed, the current cycle should finish, there should be a 12-second green on the main, and then the lights should cycle to allow a secondary green and a walk signal,even if there is no vehicle on the in-pavement sensor.

For now, I figured out the most of the program, but I couldn't figure out how to acheive the requirement of
If the light is green when the button is pressed, the current cycle should finish, there should be a 12-second green on the main, and then the lights should cycle to allow a secondary green and a walk signal,even if there is no vehicle on the in-pavement sensor.

I just got it.thanks!

Automation,

Here is a hot tip that will save you hundreds of hours later on: Label your instructions, and add rung comments that say what each rung is supposed to do.

Most of us have learned this in the "school of hard knocks". Why not take a short cut? As soon as you add an instruction, Right- click and type in a label. Then when you add a new rung, before you put ANYTHING ELSE on it, type in a rung comment. You will be amazed that when you try to describe in words what the rung does, you will think of a better way to do it.