converting fifo

[James Mcquade]

Hi everyone,

Several months ago, i asked for help in doing a fifo for a 12 station and 24 station machine in which we had an issue with our water utilities, and everyone came thru with flying colors. Thanks again !

The logic is complete and the software ran with the emulator with flying colors. Tomorrow i was to install the software and test it for our start of production next week.

HOLD Everything!!

Someone failed to tell me that the engineering study they did on the water utilities revealed that the utilities will be able to support two stations running at the same time, but not three and now they want to run two stations at the same time but not three. wished i had that information sooner.

Do any of you have a good suggestion / idea how to convert the fifo logic so i can run two stations at a time?

Management - wished they had to put up with the stuff we do, the left hand doesn't tell the right hand what its doing or what it wants.

Thanks in advance,
James

[OkiePC]

Can you post what you have? It might be pretty easy to modify or add something for this after seeing the existing structure you have followed.

[James Mcquade]

OkiePC,

i am working on posting it for you.
Company ploicy will not allow me to post the program, so i must make it look generic. Same result though.

Regards,
James

[James Mcquade]

OkiePC,

here is my progeam, i have taken out a lot of the logic, but this is it.
regards,
james

[OkiePC]

quick and dirty fix:

Search for N7:13.

It will let the fifo keep unloading as long as there are less than two bits set in the output word. This will allow requests to come in and be processed in order, and if later you decide to allow three at a time, it is easy enough to do that by only changing one LES instruction constant (or make it N7:14).

Paul

[James Mcquade]

OkiePC,
Thanks !!

i will study what you did.
always trying to learn!
james

[OkiePC]

it has a problem.
it'll clear the one already running bit.
just thought of this driving home...:








:o)

[OkiePC]

we need to instead, only hmm. green light...

count stations actually running, so when one finishes, another can be FFUd

And ensure, that they seal in once permitted to start.

[James Mcquade]

OkiePC,

i started playing with it as soon as i downloaded the file
and found that same problem.

thanks for the follow up , BUT !!!
thanks for your help!!

thanks to this site!
many of us would be in the dark without everyone's help.

james

[Lancie1]

James,

I see you run into a little problem. Unfortunately you did not take my suggestion and use "water fill" as the control for your FFU (FIFO UNLOAD). Instead, you tied your unload to the original start requests, simply unloading them in order without regard to the water AT ALL.

Now you have a problem. What can I say? Been there, done that. It would be nice if I could just convince a person that something has already been done, and a better way found. It rarely happens. We all have to learn the hard way - in the "school of hard knocks".

PS: I still have the original UNLOAD routine, if you need it. If you remember, I had 12 timers set up so that when the first running station signalled it had enough water, the next station could immediately start (the next FFU Unload would occur). With that method, it would be easy to start 2 or more stations together, by changing the Timer Done bits to whatever bit you want to use to signal the next start.