Week 25:

A few key problems were solved this week:

Problem:

When the carriers go round the MES conveyors, the carriers wait to be taken across to the other station. If there is already a carrier in the waiting position, the other carriers will do another loop of the first island. The carrier will pass through the stations it has just been to and will upload more data to the blockchain that is unwanted.

Solution:

With the addition of a stationHistory array, each station the carrier meets will have it's number added to the index of the array. For instance, stationHistory[3] = '3'

A simple IF statement is used to check if that space has already been filled in the array, if it has, no new information will be uploaded.

Problem:

When an order contains more than four products, a carrier on the MES rig will need reusing for that order, as there are only four carriers. If a carrier is reused, the blockchain receipt for the previous product will be overwritten, losing the data.

Solution:

Incorporating the previous solution helped solve this one using that same stationHistory array. Once the product has been to every station, the product travels back to station 2 again (Manual Station), where the HMI panel prompts the workman to remove the product from the production line. The stationHistory array is checked if it's completed:

stationHistory = ['Start Production', '1', '2', '3', '4','5', '6']. If this is 'True' the associated receipt gets renamed to having 'Comp' after its name followed by a counter. The counter is needed just so if the carrier gets used more than twice, the completed receipt isn't over written.

Once the product is removed, the live arrays associated are re-initialised so a new blockchain can be created for a new product.