#580 RTU gateway backplane

rtu/rtu.lua

@@ -36,7 +36,9 @@ function rtu.load_config()
     config.SVR_Channel = settings.get("SVR_Channel")
     config.RTU_Channel = settings.get("RTU_Channel")
     config.ConnTimeout = settings.get("ConnTimeout")
+    config.WirelessModem = settings.get("WirelessModem")
     config.WiredModem = settings.get("WiredModem")
+    config.PreferWireless = settings.get("PreferWireless")
     config.TrustedRange = settings.get("TrustedRange")
     config.AuthKey = settings.get("AuthKey")
 
@@ -62,7 +64,9 @@ function rtu.validate_config(cfg)
     cfv.assert_channel(cfg.RTU_Channel)
     cfv.assert_type_num(cfg.ConnTimeout)
     cfv.assert_min(cfg.ConnTimeout, 2)
+    cfv.assert_type_bool(cfg.WirelessModem)
     cfv.assert((cfg.WiredModem == false) or (type(cfg.WiredModem) == "string"))
+    cfv.assert_type_bool(cfg.PreferWireless)
     cfv.assert_type_num(cfg.TrustedRange)
     cfv.assert_min(cfg.TrustedRange, 0)
     cfv.assert_type_str(cfg.AuthKey)
@@ -288,7 +292,7 @@ end
 -- RTU Communications
 ---@nodiscard
 ---@param version string RTU version
----@param nic nic network interface device
+---@param nic nic|nil network interface device
 ---@param conn_watchdog watchdog watchdog reference
 function rtu.comms(version, nic, conn_watchdog)
     local self = {
@@ -301,30 +305,43 @@ function rtu.comms(version, nic, conn_watchdog)
 
     local insert = table.insert
 
-    if nic.isWireless() then
-        comms.set_trusted_range(config.TrustedRange)
-    end
+    -- CONDITIONAL PRIVATE FUNCTIONS --
 
-    -- PRIVATE FUNCTIONS --
-
-    -- configure modem channels
-    nic.closeAll()
-    nic.open(config.RTU_Channel)
+    -- these don't check for nic to be nil to save execution time on functions called extremely often
+    -- when the nic isn't present, the aliases _send and _send_modbus are cleared
 
     -- send a scada management packet
     ---@param msg_type MGMT_TYPE
     ---@param msg table
-    local function _send(msg_type, msg)
+    local function _nic_send(msg_type, msg)
         local s_pkt = comms.scada_packet()
         local m_pkt = comms.mgmt_packet()
 
         m_pkt.make(msg_type, msg)
         s_pkt.make(self.sv_addr, self.seq_num, PROTOCOL.SCADA_MGMT, m_pkt.raw_sendable())
 
+---@diagnostic disable-next-line: need-check-nil
         nic.transmit(config.SVR_Channel, config.RTU_Channel, s_pkt)
         self.seq_num = self.seq_num + 1
     end
 
+    -- send a MODBUS TCP packet
+    ---@param m_pkt modbus_packet
+    local function _nic_send_modbus(m_pkt)
+        local s_pkt = comms.scada_packet()
+
+        s_pkt.make(self.sv_addr, self.seq_num, PROTOCOL.MODBUS_TCP, m_pkt.raw_sendable())
+
+---@diagnostic disable-next-line: need-check-nil
+        nic.transmit(config.SVR_Channel, config.RTU_Channel, s_pkt)
+        self.seq_num = self.seq_num + 1
+    end
+
+    -- PRIVATE FUNCTIONS --
+
+    -- send a scada management packet
+    local _send = _nic_send
+
     -- keep alive ack
     ---@param srv_time integer
     local function _send_keep_alive_ack(srv_time)
@@ -355,13 +372,7 @@ function rtu.comms(version, nic, conn_watchdog)
     local public = {}
 
     -- send a MODBUS TCP packet
-    ---@param m_pkt modbus_packet
-    function public.send_modbus(m_pkt)
-        local s_pkt = comms.scada_packet()
-        s_pkt.make(self.sv_addr, self.seq_num, PROTOCOL.MODBUS_TCP, m_pkt.raw_sendable())
-        nic.transmit(config.SVR_Channel, config.RTU_Channel, s_pkt)
-        self.seq_num = self.seq_num + 1
-    end
+    public.send_modbus = _nic_send_modbus
 
     -- unlink from the server
     ---@param rtu_state rtu_state
@@ -408,6 +419,8 @@ function rtu.comms(version, nic, conn_watchdog)
     ---@param distance integer
     ---@return modbus_frame|mgmt_frame|nil packet
     function public.parse_packet(side, sender, reply_to, message, distance)
+        -- unreachable if there isn't a nic
+---@diagnostic disable-next-line: need-check-nil
         local s_pkt = nic.receive(side, sender, reply_to, message, distance)
         local pkt = nil
 
@@ -598,6 +611,34 @@ function rtu.comms(version, nic, conn_watchdog)
         end
     end
 
+    -- set the current NIC
+    ---@param _nic nic
+    function public.assign_nic(_nic)
+        if nic then nic.closeAll() end
+
+        if _nic.isWireless() then
+            comms.set_trusted_range(config.TrustedRange)
+        end
+
+        -- configure receive channels
+        _nic.closeAll()
+        _nic.open(config.RTU_Channel)
+
+        nic = _nic
+        _send = _nic_send
+        public.send_modbus = _nic_send_modbus
+    end
+
+    -- clear the current NIC
+    function public.unassign_nic()
+        _send = function () end
+        public.send_modbus = function () end
+        nic = nil
+    end
+
+    -- set the NIC if one was given
+    if nic then public.assign_nic(nic) else public.unassign_nic() end
+
     return public
 end