PSIM Emulator Silo problem

Greetings!

I'm a college student and beginner in PLC's and ladder logic, so before I tackled LogixPro that my school has, I decided to download the PSIM Emulator from the DOS era. Both are from thelearningpit website.

I chose the silo simulator as it is the closest to the experiment that I have been tasked to do in the near future with an actual PLC.

My problem with the silo experiment is that I tried to get the silo to work automatically to no avail. I searched online for any solutions just to have a point of reference and stumbled upon the only solution: https://www.youtube.com/watch?v=VwOuMcWKHxw

I corrected my rungs according to that video, since it clearly works even though the code can barely be seen in there. The entire process works for the entire first step, but once a new box comes in, the Full light on the top left panel keeps staying on. This in turn skips the other boxes that need to be filled, which is clearly a problem. The only solution I came up with is switching to Standby (F1 key), then back to Run (F2 key). The process goes smoothly once again for the first box, but then the same problem repeats itself. Not a truly automated system.


From what I understood, there should be a problem with the code, but I simply can't find it. Here is what I understood from that code:

Rung1= is Run Light off -> Standby

Rung2= is F1 (Normally Closed) on? -> is F2 (Normally Open) & is Run light on? -> energize Run light.

Rung3= Run light on? -> Full light on? & Photo sensor off? -> energize Motor

Rung4 = Full tank & Full light on? -> is F1 (Normally Closed) on? -> energize Full light

Rung5= is Photo sensor on? -> Is Level sensor off? -> is Full light off? -> energize Flow


I understand what Rung3 wants, but feel that it is wrong. I have tried changing some fields around but it usually breaks the silo or the silo stops working.
I understand what Rung4 wants as well, but it also keeps bugging me. Played around with it as well and the silo gets flooded.

Any help or solution to this is appreciated. I just want to understand what step is wrong, whether adding another rung would fix it (I tried that), whether something needs to be removed or reworked, etc.

Shameless self-bump and update.

I have added a 6th rung:
I:102 O:104
-] [- -(U)-

Where if I press F3 (which is normally open) to turn off the Full light when closed. This makes the refilling process easier than Pressing F1 to put it on standby then pressing F2 to clear the Full light and resume refilling each time. It mimics a human approval system of each item, but the fundamental problem still remains where the video shows off 1 less Rung used to achieve an actual automated process.

The problem should be in Rung4 since it deals with energizing the Full light which constantly stays on once one box is refilled. To reiterate what Rung4 does to my knowledge:

Is the Full Level Sensor on? Yes? -(proceed)->} Is F1 (normally closed) closed? yes? -(proceed)-> energize Full Light
Is Full Light on? Yes? -(proceed)---------------^

The top part of Rung4 makes absolute sense to me, since F1 which is normally closed is always closed which satisfies the condition to power the light. The level sensor also responds when full which leads to energizing the full light. What I don't understand is the bottom part of Rung4 where it asks whether the Full light is on in order to proceed with powering on the full light.

I have tried changing that branch from asking whether the Full light is on to whether the Photo sensor is on. This would make more sense to me since if both the level sensor and the photo sensors are on, it would output the Full light which would power the conveyor belt and move the box forward. Once the Level sensor is off, it should stop displaying the Full light once the box moves. Even if it does not turn off the light, once the box moves past the level sensor, it should definitely stop energizing the Full light.

The result from changing the branch is that the box starts to fill up a tiny amount, moves, fills up a tiny amount again, moves, fills again, moves, spills onto floor, then goes off and a new box spawns.

Finally solved it for those interested.
I have rewritten the rungs from scratch and came up with:


It is one rung less since I omitted the standby light, but the process starts and stops as it should with the press of the F1 and F2 keys.
After looking at the rungs and comparing them to the first post, it seems that Rung4 (first post) which I had a hunch about had a wrong input. I:100 was supposed to be I:103.
Rung4 in the original picture now reads (Rung1 in this post):

Full level sensor on? yes? -> Is photo sensor on? yes? -> energize Full light
is Full light on? yes?---------^

From what I understood it means that since the photo sensor is on and the box just became full it would output the Full light. Since the full light is on, it would activate the conveyor belt and move the box. Once the Full level sensor is deactivated, the full light stays on since the photo sensor is still on and the full light is still on, which fulfills the bottom step of the rung. Once it's off the photo sensor, the Full light turns off since there has been an interruption and it would not turn on until the next box is full.