How to get around using Enter and Exit blocks in "Prepare" flowchart (Execution error "0 isn't supported for building resource behavior flowcharts") - anylogic

I have an airlock (small room called AL_2216) between 2 areas. The airlock has many different agent types passing through it (cart, product, operator, etc). There are queuing areas on either side of the airlock.
Because the space is small, I built a short flowchart that has a queue and restricted area blocks that all agents must pass through when going through this space. If the restricted area's capacity is full, the agents wait in either the InsideQueueArea or OutsideQueueArea depending on the direction they're going.
I send agents via Exit and Enter blocks to this flowchart and it works great on the top portion of the flowchart.
BUT if I try to use an Enter or Exit block in the prepare flowchart, I get this error:
I tried using a custom block instead of Enter and Exit blocks, but that creates a new instance of the code each time and the restrictions don't work together across the multiple custom blocks.
This airlock is just one of many in my model. Without referring to the same code, I'll have multiple copies that need to refer to each other's restricted areas and the flowcharts become huge and complicated. Is there a way to get around this?
EDIT:
I'm not sure what to do with these ports. They have no properties that do anything:
EDIT2:
Here's a file to see the behavior - Model2.zip
The Prepared flowchart portion is set to "ignore" so the code will run. You can see the operators and the carts passing through AL_2216 with only 2 being allowed at a time. If you uncheck "ignore" for the prepare flowchart, the error will trigger.

AnyLogic sent the right answer!!
So I was asking Anylogic a different question and they recognized my name from this post! They sent a fix to me and it works exactly the way it should! The exception error message I was getting "out: 0 isn't supported for..." made me think the exit/enter blocks were not supported in perparation flowcharts.
But actually, the seizeCart block didn't know where to start the prep flowchart because it wasn't directly connected to the resource task start block. A quick setting change under the Advanced section of the seizeCart block defining which resource task start block to start at did the trick! Here's the email from AnyLogic:
-The error text and documentation are not sufficient for understanding this (the error text is confusing), I suppose it is obsolete error text. We will rectify the description;
-Under the question there is a more generic discussion which seems to be unrelated to the initial problem. Please let me know if I miss something or if your model does not work as you expect even after adjustment of seizeCart block property.

I think you should replace the Enter and Exit blocks that lead to the bottom input of your seizeCart Seize block with simple Port objects (from the Agent palette).
As per the help for Seize:
So it wants a direct link to a ResourceTaskStart flow and your Enter/Exit combinations might be ... not "direct" enough... Try it.

So here's what I ended up doing. It's the best I could come up with that could be easily replicated for lots of airlocks.
I've added a wait block (dummyThruAL_2216) to my Product flowchart prior to seizing the cart. This wait block injects a new Agent into sourceDummy at the cartHome node. The dummy then seizes a cart and moves through the airlock and it's restriction. Upon exiting the restriction, I check what type of agent and direct the agent to the correct exit block. The dummy agent and cart move to the Product where the dummy agent releases the cart and sinks. The sink frees the wait block and the Product seizes the cart that is right next to it and continues on it's journey.
It's an easy copy/paste to add more airlocks. Not as nice as my original, but what are you going to do... Thanks for everyone's help and suggestions.

As others have said, there are (not really documented) restrictions on what blocks you can use in preparation and wrap-up flowcharts, which mean what you're attempting won't work.
As you say, it's important to keep a single 'instance' of the airlock flow so that the restrictions (queue and restricted area) are 'global' when this represents the same physical airlock. (Otherwise a repeated custom block is precisely what you should use for each different physical airlock.)
Your best option (and assuming you needed to attach the Cart resource to the Product) is probably to
Add dummy agents (via Source block inject calls) to a separate mini-process that represents your resource preparation requirement (but now not attached to the Seize block).
Replace the Seize in your main process with a Seize-Wait-Release-Seize combination:
The Seize block seizes the cart as normal (without moving or attaching it; no 'Send seized resources' or 'Attach seized resources' options) and then injects an agent into your mini-process (which can use Exit and Enter blocks to use the airlock sub-process). This agent represents the seized resource agent (Cart) and thus should start where it starts and be animated so it looks like it. (You can make the actual Cart temporarily non-visible during this mini-process.)
When the agent reaches the end of the mini-process (at a Sink block), instantly move the related Cart to your node (use jumpTo), make it visible again and free the Product agent from the Wait block
Release the seized Cart and then immediately re-Seize it, but now attaching it (so the animation looks correct). If you use the Resource selection 'Nearest to the agent' option you should be guaranteed to seize the correct cart. (You can also use the 'Customise resource choice' option with some code to ensure that you absolutely always choose the same Cart.)
(It is simpler than the above if you don't care about having a correct animation, and you can use custom blocks to make this block combination reusable and thus not too clunky.)
Edit: A very similar alternative which also works (and is the basis for your own answer) is to have a dummy agent representing your Product in the sub-flow which seizes (and attaches) the actual Cart agent, leaving it at the Product's location to be immediately seized as above. This is slightly better since you don't have to worry about the visibility and 'jumping' of the real resource agent, plus you can move a Seize and a Release from the main flow (which now just has Wait-Seize) to the sub-flow (thus 'hiding them away').

Related

Limit the number of Pedestrian in service 'queue'?

I have a simple model which has two Pedestrian Service blocks after one another. Is there a way to limit the queue for a service so it has a 'knock-back effect' on the queue/path area before?
I assume you can add a wait block before every ped-service that frees an agent if the ped-service queue is below a certain length. But, that seems a little messy (maybe a limitation of the pedestrian library) - would be keen to hear what best practices are from the experts (cough Ben & Felipe) :)
You can add a simple wait or queue block before the service block and only let them exit the queue if the pedestrians in the service blocks are below a threshold.
You need to implement the release logic in the on enter for the queue
as well as for the exit at the service block
But, in order to make your snake path act as a queue you will need to add walls around it, else as per your example the pedestrians will group around the end of the path in a bunch. You will also need to set your pedestrain width to just more than half your path width to ensure they don't bunch inside the path

ResourceTaskStart indipendent

Is it possible to use the ResourceTaskStart block independently of the main action flowchart? All the solutions with this block, that I have found, require the resource to be seized in the main flowchart. If I instead wanted to create a parallel action flowchart, within which one of my resources performs actions, how can I do that?
You would use the Enter and Exit blocks instead. You send your resource agents to the former at some point using myEnterBlock.take(agent).
However, be careful to do this only when the resource is not seized, else it could lead to unintended problems.

Sequence of blocks

I have an agent which needs to seize two different equipment units, one excavator, and one truck. It seizes excavator first, release it and then it seizes truck. I added some functions to the release excavator block but interestingly the agent goes to seize truck block without going to release excavator block! so thus functions do not work. How this is possible?
Please see the attached file. How can I solve this? Thank you.
That's weird. Have you tried adding any other block in between seize and release exc? In some cases it happens that some code isn't executed (i.e. in the options on a selectOutput) because you defined the conditions in the block inmediately before that. But in your case the counters remain in 0 and the next ones have the same value as the previous ones (you're sure the blocks are properly connected, right? they seem to be connected at first sight).

How I can match bags an passenger in the reclaim area?

I'm simulating a security control process, and i can't do that each passenger pickup their baggage. I have tried with Match, Combine, Pickup, but I still can't execute the commands correctly.
I've created the follow flowchart, and the problem is in the wReclaimPax, pickup and wReclaimBags blocks (you can see them in the picture).
https://ibb.co/v3V57Tm
I saw this link Anylogic - Combined multiple items back to original owner to understand something, but I still need help.
I've created 3 functions:
isMatch:
if(equipaje.pasajeroLink.equals(pasajero.equipajeLink)){
return true;
}
return false;
paxBags:
for(int i=0;i<wait.size();i++){
Pasajero p=(Pasajero)wait.get(i);
if(isMatch(p,bag))
return p;
}
return null;
bagsPax:
for(int i=0;i<wait.size();i++){
Equipaje e=(Equipaje)wait.get(i);
if(isMatch(pasajero,e))
return e;
}
return null;
Assumed context
You haven't really explained how your code is related to your process but I'm assuming the following:
Because this is luggage-retrieval, you want to ensure that a passenger
agent (Pasajero) only enters the Pickup block (representing taking bag from
carousel) when his bag (Equipaje agent by the look of it) has
arrived into the wReclaimBag Wait, and been released from it to
queue4 Queue.
For this you need triggers (to remove agents from Wait blocks) when
either a passenger (Pasajero) arrives in wReclaimPax Wait, or a bag (Equipaje) arrives
in the wReclaimBag Wait (because you don't know whether the passenger or their bag will get to their respective Wait blocks first).
So your paxBags function is called in on-entry action of the wReclaimBag Wait, and your bagsPax function in the on-entry action of the wReclaimPax Wait.
Possible problems with current approach
Without knowing more of your model it's hard to say but problems I can think of based on what you've supplied are:
Your functions return the Pasajero or Equipaje if there is one that matches. Your match check relies seemingly on bidirectional connections (links) between Pasajero and Equipaje. Obviously if they're not setup properly the model won't work and, if you're using bidirectional connections you shouldn't need to check both ends.
Your functions need calling so that, if they return non null, they then free the matching agent from the other Wait block, and free themselves. Are you doing that? Without checking, there may be issues with calling free for yourself as you enter a Wait block (since this kind of depends on AnyLogic internals as to whether you count as being 'in' the block at this stage and can be freed). If this seems to be the problem you could create a timeout 0 dynamic event instance to do the free so that you're not doing it within the scope of the on-enter action.
Your pickup block (since it's been setup so that the entering agent will always want to pickup the first agent (Equipaje) in queue4) just needs to be set as waiting for quantity 1 (though see below).
If you've done all this the most likely problem is that the underlying events ordering of AnyLogic is affecting things. When you free agents I'm fairly sure the freeing actually happens in a timeout 0 event scheduled under-the-covers. So it may be that the passenger arrives at the Pickup before their Equipment arrives in queue4 though, if you set the Pickup to be "Exact quantity (wait for)", with quantity of 1, it should handle that.
The animation of the process (numbers in/out/within each block and details when clicking on blocks) should also help you debug what is going wrong; e.g., are bags being left in the Wait when they should have been released, etc.
P.S. With this kind of thing you should always create a minimal example model to make testing the issue/solution easier (and for sharing in help forums such as this where the rest of the complexity of your model is irrelevant). Often you find the problem 'naturally' in the process of trying to construct such a model that reproduces your problem in a minimal way.

Using agent parameters from main to different agent?

For a project I'm trying to select the right output if a parameter of the created agent is true. The agent is created in the main but goes into a different agent for the selection of the output. If I use a select in the main and use the statement for the parameter as condition it works fine. Whenever it enters the agent and I use the same statement it gives an error (Description: product1 cannot be resolved or is not a field. Location: testCase5/Transport/selectOutput - SelectOutput).
I tried using different conditions like main.agent.product1 . Can't seem to solve the issue. I know that it has to do something with declaration probably but I'm clueless at the moment.
//for the condition that works if I put the selectOutput in the main
agent.product1
//for the condition in the agent I tried the same but didn't work. also tried
main.agent.product1 // Gives the same error but for (Description: agentcannot be resolved or is not a field.)
(Main)agent.product1
//And a few more
In AnyLogic each block of a project flow (regardless if from the process modeling library, the pedestrian library or another) has the type of Agent that is flowing through it defined in its properties. You can find this setting as Agent type in the block's properties under Advanced.
If you fail to set this correctly (meaning this setting equals the type of Agents you let flow through it), it will still flow through, BUT: you cannot access the specific properties of the Agent type.
That said, usually you do not even have to think about, because AnyLogic has an automatism there: The first block of your process flow, typically a Source-block or a Enter-block is the only block where you have to make the correct setting, all attached blocks get it then automatically!
However this does not work when:
You have separate flows (eg. you leave one flow through an Exit-block and enter another by an Enter). You'll manually have to put the correct setting also for the first block of the second process flow.
Your process flow is continued inside of another Agent/Custom Block, as in your example. AnyLogic doesnt realize the process flow inside your custom block is logically connected to the outside process flow in main. You have to specifiy manually again the Agent type flowing through in the first block of your process inside your Custom Block.