Automatic selection

[Bottlemech 0]

I'm working on a small conveyor system that will send a rack full of utensils to 1 of 7 washing machines based on machine availability. Right now I have got it set up to choose a random washer if all of the washers are available and send the rack to that washer. What I would like to accomplish is if a washer is not available that it could be skipped when a random number is selected. I'm trying to keep the programming as simple as possible so that it can be understood by someone other than myself. I'm going to be using a IDEC FC5A with Ethernet. Any suggestions are appreciated.      Here is a link to a similar system except ours has a conveyor system in front of all the washers. http://www.belimed.com/BelimedASPX/media/Media-Library/Resources/Videos/Automation/WA290-Automation-in-action.webm?width=300&height=200&ext=.webm Edited 15 Dec 2015 by Bottlemech

[panic mode 246]

use priority decoder Select = (Available) AND (- Available) where Available contains bits representing stations ready to take a job. least significant bit should be the nearest station, etc. using just two instructions (subtract and AND) will make this easy to implement on any platform    

[Bottlemech 0]

After attempting to use a decoder and not really succeeding I decided to use a shift register. The register will shift a single bit through 8 addresses until it finds a washer that is ready to accept a load and it will pause at that address until that washer is no longer available.