cc-mek-scada/reactor-plc/plc.lua

function scada_link(comms)
    local linked = false
    local link_timeout = os.startTimer(5)

    comms.send_link_req()
    print_ts("sent link request")
    
    repeat
        local event, p1, p2, p3, p4, p5 = os.pullEvent()
    
        -- handle event
        if event == "timer" and param1 == link_timeout then
            -- no response yet
            print("...no response");
            comms.send_link_req()
            print_ts("sent link request")
            link_timeout = os.startTimer(5)
        elseif event == "modem_message" then
            -- server response? cancel timeout
            if link_timeout ~= nil then
                os.cancelTimer(link_timeout)
            end

            local packet = comms.make_packet(p1, p2, p3, p4, p5)

            -- handle response
            local response = comms.handle_link(packet)
            if response == nil then
                print_ts("invalid link response, bad channel?\n")
                return
            elseif response == true then
                print_ts("...linked!\n")
                linked = true
            else
                print_ts("...denied, exiting\n")
                return
            end
        end
    until linked
end

-- Internal Safety System
-- identifies dangerous states and SCRAMs reactor if warranted
-- autonomous from main control
function iss_init(reactor)
    local self = {
        _reactor = reactor,
        _tripped = false,
        _trip_cause = ""
    }

    local check = function ()
        local status = "ok"
        
        -- check system states in order of severity
        if self.damage_critical() then
            status = "dmg_crit"
        elseif self.high_temp() then
            status = "high_temp"
        elseif self.excess_heated_coolant() then
            status = "heated_coolant_backup"
        elseif self.excess_waste() then
            status = "full_waste"
        elseif self.insufficient_fuel() then
            status = "no_fuel"
        elseif self._tripped then
            status = self._trip_cause
        else
            self._tripped = false
        end
    
        if status ~= "ok" then
            self._tripped = true
            self._trip_cause = status
            self._reactor.scram()
        end
    
        return self._tripped, status
    end

    local reset = function ()
        self._tripped = false
        self._trip_cause = ""
    end
    
    local damage_critical = function ()
        return self._reactor.getDamagePercent() >= 100
    end
    
    local excess_heated_coolant = function ()
        return self._reactor.getHeatedCoolantNeeded() == 0
    end
    
    local excess_waste = function ()
        return self._reactor.getWasteNeeded() == 0
    end

    local high_temp = function ()
        -- mekanism: MAX_DAMAGE_TEMPERATURE = 1_200
        return self._reactor.getTemperature() >= 1200
    end
    
    local insufficient_fuel = function ()
        return self._reactor.getFuel() == 0
    end

    local no_coolant = function()
        return self._reactor.getCoolantFilledPercentage() < 2
    end

    return {
        check = check,
        reset = reset,
        damage_critical = damage_critical,
        excess_heated_coolant = excess_heated_coolant,
        excess_waste = excess_waste,
        high_temp = high_temp,
        insufficient_fuel = insufficient_fuel,
        no_coolant = no_coolant
    }
end