work on PLC comms

reactor-plc/startup.lua

@@ -37,11 +37,13 @@ if not modem.isOpen(config.LISTEN_PORT) then
     modem.open(config.LISTEN_PORT)
 end
 
-local comms = comms.rplc_comms(config.REACTOR_ID, modem, config.LISTEN_PORT, config.SERVER_PORT, reactor)
+local plc_comms = comms.rplc_comms(config.REACTOR_ID, modem, config.LISTEN_PORT, config.SERVER_PORT, reactor)
 
 -- attempt server connection
--- exits application if connection is denied
-plc.scada_link(comms)
+-- exit application if connection is denied
+if ~plc.scada_link(plc_comms) then
+    return
+end
 
 -- comms watchdog, 3 second timeout
 local conn_watchdog = watchdog.new_watchdog(3)
@@ -51,28 +53,47 @@ local conn_watchdog = watchdog.new_watchdog(3)
 local loop_tick = os.startTimer(0.05)
 local ticks_to_update = 5
 
+-- runtime variables
+local control_state = false
+
 -- event loop
 while true do
     local event, param1, param2, param3, param4, param5 = os.pullEvent()
 
+    if event == "peripheral_detach" then
+        print_ts("[fatal] lost a peripheral, stopping...\n")
+        -- todo: determine which disconnected and what is left
+        -- hopefully it wasn't the reactor
+        reactor.scram()
+        -- send an alarm: plc_comms.send_alarm(ALARMS.PLC_DC) ?
+        return
+    end
+
     -- check safety (SCRAM occurs if tripped)
-    local iss_status, iss_tripped = iss.check()
+    local iss_status, iss_tripped, iss_first = iss.check()
+    if iss_first then
+        plc_comms.send_iss_alarm(iss_status)
+    end
 
     -- handle event
     if event == "timer" and param1 == loop_tick then
-        -- basic event tick, send updated data if it is time
+        -- basic event tick, send updated data if it is time (4Hz)
         ticks_to_update = ticks_to_update - 1
         if ticks_to_update == 0 then
+            plc_comms.send_status(control_state, iss_tripped)
             ticks_to_update = 5
         end
     elseif event == "modem_message" then
         -- got a packet
-        -- feed the watchdog first so it doesn't eat our packets
+        -- feed the watchdog first so it doesn't uhh,,,eat our packets
         conn_watchdog.feed()
 
+        local packet = comms.make_packet(p1, p2, p3, p4, p5)
+        plc_comms.handle_packet(packet)
+
     elseif event == "timer" and param1 == conn_watchdog.get_timer() then
         -- haven't heard from server recently? shutdown
-        reactor.scram()
+        iss.trip_timeout()
         print_ts("[alert] server timeout, reactor disabled\n")
     end
 end