oil.lua

local net = peripheral.find("modem")
local chan = 2000
local nchan = 1999

function supersosik()

    local event, modemSide, senderChannel, replyChannel, message, distance = os.pullEvent("modem_message")

    if message == "on" then
        rs.setAnalogOutput("bottom", 1)
        net.transmit(nchan, nchan, "Answer from station: \nStarted pumping")
    elseif message == "off" then
        rs.setAnalogOutput("bottom", 0)
        net.transmit(nchan, nchan, "Answer from station: \nStopped")
    else
        net.transmit(nchan, nchan, "Answer from oil station: \nUnknown command")
    end
end

while true do

if net.isOpen(chan) then
    supersosik()
else
    net.open(chan)
    supersosik()
end

end