diff --git a/apps/modbus/src/modbus_service.erl b/apps/modbus/src/modbus_service.erl
index abab248..54cfe89 100644
--- a/apps/modbus/src/modbus_service.erl
+++ b/apps/modbus/src/modbus_service.erl
@@ -28,12 +28,23 @@
 -define(CONNECTED, connected).
 
 -record(state, {
-    port,
+    ast :: #ast{},
+
+    %% 连接模式
+    mode :: rtu | tcp,
+
+    port :: erlang:port() | undefined,
+    %% 延迟的毫秒数
+    delay_ms = 0,
+
+    socket :: gen_tcp:socket() | undefined,
+
+    %% #{slaveId => DevicePid}
+    devices_map = #{},
+
     packet_id = 1,
     queue = queue:new(),
     is_pending = false :: boolean(),
-    %% 延迟的毫秒数
-    delay_ms = 0,
 
     %% 未确认的消息
     inflight = #{},
@@ -66,21 +77,29 @@ start_link(AST = #ast{}) ->
 %% @doc Whenever a gen_statem is started using gen_statem:start/[3,4] or
 %% gen_statem:start_link/[3,4], this function is called by the new
 %% process to initialize.
-init([AST = #ast{modbus = Modbus, devices = Devices}]) ->
+init([AST = #ast{modbus = Modbus = #modbus{transport = Transport}, devices = Devices}]) ->
     lager:debug("modbus is: ~p", [Modbus]),
     Device = hd(Devices),
     lager:debug("devices is: ~p", [Device#modbus_device.metrics]),
     % Res = connect(Transport),
     % lager:debug("connect res: ~p", [Res]),
 
-    {ok, DevicePid} = modbus_device:start_link(hd(Devices)),
-    lager:debug("device pid: ~p", [DevicePid]),
+    %% 建立连接
+    erlang:start_timer(0, self(), modbus_connect),
 
+    %% 启动设备相关的进程
+    DevicesPids = lists:map(fun(Device = #modbus_device{slave_id = SlaveId}) ->
+        {ok, DevicePid} = modbus_device:start_link(self(), Device),
+        {SlaveId, DevicePid}
+                        end, Devices),
+    DevicesMap = maps:from_list(DevicesPids),
+
+    lager:debug("device pid: ~p", [DevicesMap]),
 
     %{ok, AccessLogPid} = modbus_logger:start_link(AccessLog),
     %{ok, ErrorLogPid} = modbus_logger:start_link(ErrorLog),
 
-    {ok, ?DISCONNECTED, #state{queue = queue:new(), packet_id = 1}}.
+    {ok, ?DISCONNECTED, #state{ast = AST, queue = queue:new(), packet_id = 1, devices_map = DevicesMap}}.
 
 %% @private
 %% @doc This function is called by a gen_statem when it needs to find out
@@ -128,6 +147,51 @@ handle_event(info, {Port, {data, <<?MODBUS_READ:8, PacketId:32, Val:32>>}}, ?CON
 
     {keep_state, State#state{inflight = NInflight}};
 
+%% port退出
+handle_event(info, {Port, {exit_status, Code}}, ?CONNECTED, State = #state{mode = rtu, port = Port}) ->
+    lager:debug("[efka_service] port: ~p, exit with code: ~p", [Port, Code]),
+    retry_connect(),
+    {next_state, ?DISCONNECTED, State#state{port = undefined}};
+
+%% 处理port的退出消息
+handle_event(info, {'EXIT', Port, Reason}, ?CONNECTED, State = #state{mode = rtu, port = Port}) ->
+    lager:debug("[efka_service] port: ~p, exit with code: ~p", [Port, Reason]),
+    retry_connect(),
+    {next_state, ?DISCONNECTED, State#state{port = undefined}};
+
+%% tcp退出
+handle_event(info, {tcp_closed, Socket}, ?CONNECTED, State = #state{mode = tcp, socket = Socket}) ->
+    lager:debug("[efka_service] socket: ~p, exit with tcp_closed", [Socket]),
+    retry_connect(),
+    {next_state, ?DISCONNECTED, State#state{socket = undefined}};
+
+%% 处理tcp的退出消息
+handle_event(info, {tcp_error, Socket, Reason}, ?CONNECTED, State = #state{mode = tcp, socket = Socket}) ->
+    lager:debug("[efka_service] socket: ~p, exit with code: ~p", [Socket, Reason]),
+    retry_connect(),
+    {next_state, ?DISCONNECTED, State#state{socket = undefined}};
+
+%% 建立连接, todo is_pending的状态要形成闭环
+handle_event(info, modbus_connect, ?DISCONNECTED, State = #state{ast = #ast{modbus = #modbus{transport = Transport}}, queue = Q}) ->
+    case connect(Transport) of
+        {ok, ConnectResult} ->
+            Actions = case not queue:is_empty(Q) of
+                          true  -> [{next_event, info, read_next}];
+                          false -> []
+                      end,
+            case ConnectResult of
+                {rtu, Port, DelayMs} ->
+                    {next_state, ?CONNECTED, State#state{mode = rtu, port = Port, delay_ms = DelayMs}, Actions};
+                Socket ->
+                    {next_state, ?CONNECTED, State#state{mode = tcp, socket = Socket}, Actions}
+            end;
+        {error, Reason} ->
+            lager:warning("[modbus_serivce] connect get error: ~p", [Reason]),
+            %% 5秒后重试
+            retry_connect(),
+            {keep_state, State}
+    end;
+
 handle_event(_EventType, _EventContent, _StateName, State = #state{}) ->
     NextStateName = the_next_state_name,
     {next_state, NextStateName, State}.
@@ -150,7 +214,7 @@ code_change(_OldVsn, StateName, State = #state{}, _Extra) ->
 %%%===================================================================
 
 %% databits为8位
-connect(#modbus{transport = #modbus_transport_rtu{port = Port, baudrate = BaudRate, stopbits = StopBits, parity = Parity, timeout = Timeout}}) ->
+connect(#modbus_transport_rtu{port = Port, baudrate = BaudRate, stopbits = StopBits, parity = Parity, timeout = Timeout}) ->
     RealExecCmd = "",
     Port = erlang:open_port({spawn_executable, RealExecCmd}, [binary, {packet, 2}, exit_status]),
 
@@ -160,9 +224,8 @@ connect(#modbus{transport = #modbus_transport_rtu{port = Port, baudrate = BaudRa
     ConnectCmd = <<?MODBUS_CONNECT:8, Len0:8, Port/binary, BaudRate:32, StopBits:8, Parity:8, Timeout:32>>,
     %% 建立连接
     Port ! {self(), {command, ConnectCmd}},
-    ok;
-
-connect(#modbus{transport = #modbus_transport_tcp{host = Host, port = Port, timeout = Timeout0}}) ->
+    {ok, {rtu, Port, DelayMs}};
+connect(#modbus_transport_tcp{host = Host, port = Port, timeout = Timeout0}) ->
     Timeout = case is_integer(Timeout0) andalso Timeout0 > 0 of
                   true ->
                       Timeout0;
@@ -176,4 +239,7 @@ frame_delay(BaudRate, DataBits, Parity, StopBits) when is_integer(BaudRate), is_
     %% 计算1个字符的总位数
     CharBits = 1 + DataBits + case Parity of 0 -> 0; _ -> 1 end + StopBits,
     %% 3.5字符时间（毫秒), 预留20%的时间
-    erlang:ceil((3500 * CharBits) / BaudRate * 1.2).
\ No newline at end of file
+    erlang:ceil((3500 * CharBits) / BaudRate * 1.2).
+
+retry_connect() ->
+    erlang:start_timer(5000, self(), modbus_connect).
\ No newline at end of file