trainID

local modem = peripheral.wrap("back")
modem.open(999)

function getID(f)
    local id = "Pending"
    if f == 1 then
        id = "Raw Ore Delivery"
    end
    return id
end

function messageHandler(message, id)
    if message[5] == "ID Request" then
        print("Received "..message[5])
        modem.transmit(998,999, id)
        print("Sending refresh command")
        modem.transmit(997,999, "refresh")
    end
end

function screenClear(y)
    local mX, mY = term.getSize()
    for i = y,mY do
        term.setCursorPos(1,i)
        term.clearLine()
    end
    term.setCursorPos(1,y)
end

while true do
    term.clear()
    term.setCursorPos(1,1)
    print("Train Identifier\n")
    local looping = true
    local trainID = "Pending"
    local x,y = term.getCursorPos()
    while looping do
        screenClear(y)
        print("Train ID = "..trainID)
        local event = {os.pullEvent()}
        if event[1] == "redstone" then
            print("Train Arrived")
            print("Setting ID to: "..trainID)
            local red = redstone.getBundledInput("left")
            trainID = getID(red)
        elseif event[1] == "modem_message" then
            messageHandler(event, trainID)
            looping = false
        end
    end
end