Receiver

modem = peripheral.wrap("left")
modem.open(1)

if rs.getOutput("left") == true then
    modem.transmit(1, 1, "ON")
end
if rs.getOutput("left") == false then
    modem.transmit(1, 1, "OFF")
end

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

if message == "toggle" then
    if rs.getOutput("left") == false then
        rs.setOutput("left", true)
    else
        rs.setOUtput("left", false)
end
sleep(0.1)
shell.run("startup")