simulate electronic board that communicate by socket

device_server.erl

-module(device_server).

-compile(export_all).

start() ->
	{ok, Listen} = gen_tcp:listen(51, [binary,
					    {reuseaddr, true},
					    {active, true}]),
	{ok, Socket} = gen_tcp:accept(Listen),
	gen_tcp:close(Listen),
	loop(Socket).

loop(Socket) ->
	receive
	    {tcp, Socket, Command} ->
			case Command of
				<<"checked\r\n">> ->
					gen_tcp:send(Socket,<<"DRY1: OPEN\r\nDRY2: OPEN\r\nDRY3: OPEN\r\nDRY4: OPEN\r\nDRY5: OPEN\r\nDRY6: OPEN\r\nDRY7: OPEN\r\nDRY8: OPEN\r\nDRY9: OPEN\r\nDRY10: OPEN\r\nDRY11: OPEN\r\nDRY12: OPEN\r\nDRY13: OPEN\r\nDRY14: OPEN\r\nDRY15: OPEN\r\nDRY16: OPEN\r\n">>);
                <<"output\r\n">> ->
                    gen_tcp:send(Socket,<<"RELAY1: OFF\r\nRELAY2: OFF\r\nRELAY3: OFF\r\nRELAY4: OFF\r\nRELAY5: OFF\r\nRELAY6: OFF\r\nRELAY7: OFF\r\nRELAY8: OFF\r\nRELAY9: OFF\r\nRELAY10: OFF\r\nRELAY11: OFF\r\nRELAY12: OFF\r\nRELAY13: OFF\r\nRELAY14: OFF\r\nRELAY15: OFF\r\nRELAY16: OFF\r\n">>)
            end,
            loop(Socket);
	    {tcp_closed, Socket} ->
            gen_tcp:close(Socket),
            io:format("Server socket ~p closed~n",[Socket])
	end.