#11 configurable 'networked' setting for PLCs that allows for standalone ISS-only mode

reactor-plc/config.lua

@@ -1,3 +1,5 @@
+-- set to false to run in standalone mode (safety regulation only)
+NETWORKED = true
 -- unique reactor ID
 REACTOR_ID  = 1
 -- port to send packets TO server

reactor-plc/startup.lua

@@ -22,6 +22,8 @@ ppm.mount_all()
 local reactor = ppm.get_device("fissionReactor")
 local modem = ppm.get_device("modem")
 
+local networked = config.NETWORKED
+
 local plc_state = {
     init_ok = true,
     scram = true,       -- treated as latching e-stop, all conditions must be OK to set false
@@ -38,7 +40,7 @@ if reactor == nil then
     plc_state.degraded = true
     plc_state.no_reactor = true
 end
-if modem == nil then
+if networked and modem == nil then
     if reactor ~= nil then
         print_ts("No modem found. Disabling reactor and running in a degraded state...\n")
         reactor.scram()
@@ -52,37 +54,46 @@ if modem == nil then
     plc_state.no_modem = true
 end
 
-::init::
-if plc_state.init_ok then
-    -- just booting up, no fission allowed (neutrons stay put thanks)
-    reactor.scram()
-
-    -- init internal safety system
-    local iss = plc.iss_init(reactor)
-    log._debug("iss init")
-
-    -- start comms
-    local plc_comms = plc.comms_init(config.REACTOR_ID, modem, config.LISTEN_PORT, config.SERVER_PORT, reactor, iss)
-    log._debug("comms init")
-
-    -- comms watchdog, 3 second timeout
-    local conn_watchdog = watchdog.new_watchdog(3)
-    log._debug("conn watchdog started")
-
-    -- loop clock (10Hz, 2 ticks)
-    local loop_tick = os.startTimer(0.05)
-    log._debug("loop clock started")
-else
-    log._warning("booted in a degraded state, awaiting peripheral connections...")
-end
+local iss = nil
+local plc_comms = nil
+local conn_watchdog = nil
 
 -- send status updates at ~3.33Hz (every 6 server ticks) (every 3 loop ticks)
 -- send link requests at 0.5Hz (every 40 server ticks) (every 20 loop ticks)
 local UPDATE_TICKS = 3
 local LINK_TICKS = 20
 
--- start by linking
-local ticks_to_update = LINK_TICKS
+local loop_tick = nil
+local ticks_to_update = LINK_TICKS  -- start by linking
+
+-- initialize PLC
+::init::
+if plc_state.init_ok then
+    -- just booting up, no fission allowed (neutrons stay put thanks)
+    reactor.scram()
+
+    -- init internal safety system
+    iss = plc.iss_init(reactor)
+    log._debug("iss init")
+
+    if networked then
+        -- start comms
+        plc_comms = plc.comms_init(config.REACTOR_ID, modem, config.LISTEN_PORT, config.SERVER_PORT, reactor, iss)
+        log._debug("comms init")
+
+        -- comms watchdog, 3 second timeout
+        conn_watchdog = watchdog.new_watchdog(3)
+        log._debug("conn watchdog started")
+    else
+        log._debug("running without networking")
+    end
+
+    -- loop clock (10Hz, 2 ticks)
+    loop_tick = os.startTimer(0.05)
+    log._debug("loop clock started")
+else
+    log._warning("booted in a degraded state, awaiting peripheral connections...")
+end
 
 -- event loop
 while true do
@@ -93,7 +104,7 @@ while true do
         -- if it disconnected, isPowered will return nil (and error logs will get spammed at 10Hz, so disable reporting)
         -- in that case, SCRAM won't be called until it reconnects (this is the expected use of this check)
         ppm.disable_reporting()
-        if plc_state.scram and reactor.isPowered() then
+        if plc_state.degraded or (plc_state.scram and reactor.isPowered()) then
             reactor.scram()
         end
         ppm.enable_reporting()
@@ -108,7 +119,7 @@ while true do
             log._error("reactor disconnected!")
             plc_state.no_reactor = true
             -- send an alarm: plc_comms.send_alarm(ALARMS.PLC_PERI_DC) ?
-        elseif device.type == "modem" then
+        elseif networked and device.type == "modem" then
             print_ts("modem disconnected!\n")
             log._error("modem disconnected!")
             plc_state.no_modem = true
@@ -139,14 +150,16 @@ while true do
 
             if plc_state.init_ok then
                 iss.reconnect_reactor(device)
-                plc_comms.reconnect_reactor(device)
+                if networked then
+                    plc_comms.reconnect_reactor(device)
+                end
             end
 
             -- determine if we are still in a degraded state
-            if get_device("modem") not nil then
+            if not networked or get_device("modem") not nil then
                 plc_state.degraded = false
             end
-        elseif device.type == "modem" then
+        elseif networked and device.type == "modem" then
             -- reconnected modem
             if plc_state.init_ok then
                 plc_comms.reconnect_modem(device)
@@ -172,31 +185,29 @@ while true do
     if not plc_state.degraded then
         local iss_tripped, iss_status, iss_first = iss.check()
         plc_state.scram = plc_state.scram or iss_tripped
-        if iss_first then
+        if networked and iss_first then
             plc_comms.send_iss_alarm(iss_status)
         end
     end
 
     -- handle event
-    if event == "timer" and param1 == loop_tick then
-        if not plc_state.no_modem then
-            -- basic event tick, send updated data if it is time (~3.33Hz)
-            -- iss was already checked (main reason for this tick rate)
-            ticks_to_update = ticks_to_update - 1
+    if event == "timer" and param1 == loop_tick and networked and not plc_state.no_modem then
+        -- basic event tick, send updated data if it is time (~3.33Hz)
+        -- iss was already checked (that's the main reason for this tick rate)
+        ticks_to_update = ticks_to_update - 1
 
-            if plc_comms.is_linked() then
-                if ticks_to_update <= 0 then
-                    plc_comms.send_status(iss_tripped)
-                    ticks_to_update = UPDATE_TICKS
-                end
-            else
-                if ticks_to_update <= 0 then
-                    plc_comms.send_link_req()
-                    ticks_to_update = LINK_TICKS
-                end
+        if plc_comms.is_linked() then
+            if ticks_to_update <= 0 then
+                plc_comms.send_status(iss_tripped)
+                ticks_to_update = UPDATE_TICKS
+            end
+        else
+            if ticks_to_update <= 0 then
+                plc_comms.send_link_req()
+                ticks_to_update = LINK_TICKS
             end
         end
-    elseif event == "modem_message" then
+    elseif event == "modem_message" and networked and not plc_state.no_modem then
         -- got a packet
         -- feed the watchdog first so it doesn't uhh...eat our packets
         conn_watchdog.feed()
@@ -204,7 +215,7 @@ while true do
         local packet = plc_comms.parse_packet(p1, p2, p3, p4, p5)
         plc_comms.handle_packet(packet)
         plc_state.scram = plc_state.scram or plc_comms.is_scrammed()
-    elseif event == "timer" and param1 == conn_watchdog.get_timer() then
+    elseif event == "timer" and param1 == conn_watchdog.get_timer() and networked then
         -- haven't heard from server recently? shutdown reactor
         plc_state.scram = true
         plc_comms.unlink()