Getting parts from three conveyors in our defined order

Hi,
Please find my model (6.1 verison) attached to your reference.

My problem is, I want the queue to receive parts from three conveyors like Round robin fashion, but my model stops, when any one conveyor is not having parts to fed the queue.

The queue must get the parts as like the following conditions.

1st condition - when all three conveyors have parts to fed, then receive parts from conveyor-1 & 2 & 3.

2nd condition - when any one conveyor doesn't have parts to fed, then receive parts from other two conveyors (for eg: if conveyor-1 is stopped, then parts to be received from conveyor-2 & 3.

3rd condition - when any two conveyor doesn't have parts to fed, then receive parts from third conveyor until it also stops feeding the parts.

Kindly give your valuable inputs/thoughts about to solve this problem.

Thanks to one and all,
Regards,
RK

Sounds like the "round robin if available" pick option.

Jason,
Thanks for your input. I have tried using that option also, but it takes randomly from the port, which is available with parts (, its not following the condition which i said above.

My model condition for receiving parts from three conveyor is,
First loop- one part from conveyor-1 & one part from conveyor-2 & one part from conveyor-3. this same loop is continued until the part supply from conveyor-1 is stopped. Then my second loop must be fired,

second loop- one part from conveyor-2 & one part from conveyor-3. this same loop is continued until the part supply from conveyor-2 (or) 3 is stopped.

Then balance parts from conveyor-2(or)3 is to be fed to the queue.

I think, i have explained clearly about my problem situation.

Thanks,
Regards,
RK

Looks like there might be a problem with 'round robin if available' since ipavailable() is often returning false - defaulting to first available. In turn is seems Opopen is the culprit, returning 0 for the conveyors.

Hi all,
I welcome further more inputs / ideas / suggestions from you all to solve this issue (Round robin-if available not working correctly).

I tried with assigning ("IF") condition inside the round robin-if available code, in Queue to open the input ports based on the total demand parts & the received part count. its working fine to some extent.

Is there any other way to write a flexsim code without using IF condition inside the round robin-if available.

Thank you,
Regards,
RK

This should not be a very complex problem I guess. As far as I know of flexsim if you have attached the conveyor 1,2,3 to the respective input ports of the queue.. it will give preference in that order..
I am using something similar in my model and if there is nothing available at the first input port it automatically picks up from the second...

hi,

my first approach was wrong. I need the pull strategy to look for the next port to release an item. The item state must be FRSTATE_READY.

treenode current = ownerobject(c);
/**next round robin fashion port*/
int nextport = getlabelnum(current,"f_curinport");
for(int lap = 0; lap < nrip(current); lap++)
{
    if (nextport > nrip(current)) nextport = 1; // continue with an existing port
    if (getitemstate(first(inobject(current,nextport))) == FRSTATE_READY)
    {
        setlabelnum(current,"f_curinport",nextport+1);
        return nextport;
    }
    nextport++;
}

Joerg