spawn

rednet.open("bottom")

local interval = 30

os.queueEvent("timer")
while true do
  local ev, p1, p2 = os.pullEvent()

  if ev == "timer" then
    os.startTimer(interval)
  end

  if ev == "rednet_message" then
    local tbl = {}
    print("Message:"..p2)

    for i in string.gmatch(p2,"%S+") do
      table.insert(tbl,i)
    end

    if tbl[1] == os.getComputerLabel() then
      if tbl[2] == "on" then
        rs.setOutput("top",true)
      end

      if tbl[2] == "off" then
        rs.setOutput("top",false)
      end
    end
  end
end