local comms = require("scada-common.comms") local log = require("scada-common.log") local mqueue = require("scada-common.mqueue") local types = require("scada-common.types") local util = require("scada-common.util") local databus = require("supervisor.databus") local svqtypes = require("supervisor.session.svqtypes") local plc = {} local PROTOCOL = comms.PROTOCOL local RPLC_TYPE = comms.RPLC_TYPE local MGMT_TYPE = comms.MGMT_TYPE local PLC_AUTO_ACK = comms.PLC_AUTO_ACK local UNIT_COMMAND = comms.UNIT_COMMAND -- retry time constants in ms local INITIAL_WAIT = 1500 local INITIAL_AUTO_WAIT = 1000 local RETRY_PERIOD = 1000 local PLC_S_CMDS = { SCRAM = 1, ASCRAM = 2, ENABLE = 3, DISABLE = 4, RPS_RESET = 5, RPS_AUTO_RESET = 6 } local PLC_S_DATA = { BURN_RATE = 1, RAMP_BURN_RATE = 2, AUTO_BURN_RATE = 3 } plc.PLC_S_CMDS = PLC_S_CMDS plc.PLC_S_DATA = PLC_S_DATA local PERIODICS = { KEEP_ALIVE = 2000 } -- PLC supervisor session ---@nodiscard ---@param id integer session ID ---@param s_addr integer device source address ---@param reactor_id integer reactor ID ---@param in_queue mqueue in message queue ---@param out_queue mqueue out message queue ---@param timeout number communications timeout ---@param fp_ok boolean if the front panel UI is running function plc.new_session(id, s_addr, reactor_id, in_queue, out_queue, timeout, fp_ok) -- print a log message to the terminal as long as the UI isn't running local function println(message) if not fp_ok then util.println_ts(message) end end local log_header = "plc_session(" .. id .. "): " local self = { commanded_state = false, commanded_burn_rate = 0.0, auto_cmd_token = 0, ramping_rate = false, auto_lock = false, -- connection properties seq_num = 0, r_seq_num = nil, connected = true, received_struct = false, received_status_cache = false, conn_watchdog = util.new_watchdog(timeout), last_rtt = 0, -- periodic messages periodics = { last_update = 0, keep_alive = 0 }, -- when to next retry one of these requests retry_times = { struct_req = (util.time() + 500), status_req = (util.time() + 500), disable_req = 0, scram_req = 0, ascram_req = 0, burn_rate_req = 0, rps_reset_req = 0 }, -- command acknowledgements acks = { disable = true, scram = true, ascram = true, burn_rate = true, rps_reset = true }, -- session database ---@class reactor_db sDB = { auto_ack_token = 0, last_status_update = 0, control_state = false, no_reactor = false, formed = false, rps_tripped = false, rps_trip_cause = "ok", ---@type rps_trip_cause ---@class rps_status rps_status = { high_dmg = false, high_temp = false, low_cool = false, ex_waste = false, ex_hcool = false, no_fuel = false, fault = false, timeout = false, manual = false, automatic = false, sys_fail = false, force_dis = false }, ---@class mek_status mek_status = { heating_rate = 0.0, status = false, burn_rate = 0.0, act_burn_rate = 0.0, temp = 0.0, damage = 0.0, boil_eff = 0.0, env_loss = 0.0, fuel = 0, fuel_need = 0, fuel_fill = 0.0, waste = 0, waste_need = 0, waste_fill = 0.0, ccool_type = "?", ccool_amnt = 0, ccool_need = 0, ccool_fill = 0.0, hcool_type = "?", hcool_amnt = 0, hcool_need = 0, hcool_fill = 0.0 }, ---@class mek_struct mek_struct = { length = 0, width = 0, height = 0, min_pos = types.new_zero_coordinate(), max_pos = types.new_zero_coordinate(), heat_cap = 0, fuel_asm = 0, fuel_sa = 0, fuel_cap = 0, waste_cap = 0, ccool_cap = 0, hcool_cap = 0, max_burn = 0.0 } } } ---@class plc_session local public = {} -- copy in the RPS status ---@param rps_status table local function _copy_rps_status(rps_status) self.sDB.rps_tripped = rps_status[1] self.sDB.rps_trip_cause = rps_status[2] self.sDB.rps_status.high_dmg = rps_status[3] self.sDB.rps_status.high_temp = rps_status[4] self.sDB.rps_status.low_cool = rps_status[5] self.sDB.rps_status.ex_waste = rps_status[6] self.sDB.rps_status.ex_hcool = rps_status[7] self.sDB.rps_status.no_fuel = rps_status[8] self.sDB.rps_status.fault = rps_status[9] self.sDB.rps_status.timeout = rps_status[10] self.sDB.rps_status.manual = rps_status[11] self.sDB.rps_status.automatic = rps_status[12] self.sDB.rps_status.sys_fail = rps_status[13] self.sDB.rps_status.force_dis = rps_status[14] end -- copy in the reactor status ---@param mek_data table local function _copy_status(mek_data) -- copy status information self.sDB.mek_status.status = mek_data[1] self.sDB.mek_status.burn_rate = mek_data[2] self.sDB.mek_status.act_burn_rate = mek_data[3] self.sDB.mek_status.temp = mek_data[4] self.sDB.mek_status.damage = mek_data[5] self.sDB.mek_status.boil_eff = mek_data[6] self.sDB.mek_status.env_loss = mek_data[7] -- copy container information self.sDB.mek_status.fuel = mek_data[8] self.sDB.mek_status.fuel_fill = mek_data[9] self.sDB.mek_status.waste = mek_data[10] self.sDB.mek_status.waste_fill = mek_data[11] self.sDB.mek_status.ccool_type = mek_data[12] self.sDB.mek_status.ccool_amnt = mek_data[13] self.sDB.mek_status.ccool_fill = mek_data[14] self.sDB.mek_status.hcool_type = mek_data[15] self.sDB.mek_status.hcool_amnt = mek_data[16] self.sDB.mek_status.hcool_fill = mek_data[17] -- update computable fields if we have our structure if self.received_struct then self.sDB.mek_status.fuel_need = self.sDB.mek_struct.fuel_cap - self.sDB.mek_status.fuel_fill self.sDB.mek_status.waste_need = self.sDB.mek_struct.waste_cap - self.sDB.mek_status.waste_fill self.sDB.mek_status.cool_need = self.sDB.mek_struct.ccool_cap - self.sDB.mek_status.ccool_fill self.sDB.mek_status.hcool_need = self.sDB.mek_struct.hcool_cap - self.sDB.mek_status.hcool_fill end end -- copy in the reactor structure ---@param mek_data table local function _copy_struct(mek_data) self.sDB.mek_struct.length = mek_data[1] self.sDB.mek_struct.width = mek_data[2] self.sDB.mek_struct.height = mek_data[3] self.sDB.mek_struct.min_pos = mek_data[4] self.sDB.mek_struct.max_pos = mek_data[5] self.sDB.mek_struct.heat_cap = mek_data[6] self.sDB.mek_struct.fuel_asm = mek_data[7] self.sDB.mek_struct.fuel_sa = mek_data[8] self.sDB.mek_struct.fuel_cap = mek_data[9] self.sDB.mek_struct.waste_cap = mek_data[10] self.sDB.mek_struct.ccool_cap = mek_data[11] self.sDB.mek_struct.hcool_cap = mek_data[12] self.sDB.mek_struct.max_burn = mek_data[13] end -- mark this PLC session as closed, stop watchdog local function _close() self.conn_watchdog.cancel() self.connected = false databus.tx_plc_disconnected(reactor_id) end -- send an RPLC packet ---@param msg_type RPLC_TYPE ---@param msg table local function _send(msg_type, msg) local s_pkt = comms.scada_packet() local r_pkt = comms.rplc_packet() r_pkt.make(reactor_id, msg_type, msg) s_pkt.make(s_addr, self.seq_num, PROTOCOL.RPLC, r_pkt.raw_sendable()) out_queue.push_packet(s_pkt) self.seq_num = self.seq_num + 1 end -- send a SCADA management packet ---@param msg_type MGMT_TYPE ---@param msg table local function _send_mgmt(msg_type, msg) local s_pkt = comms.scada_packet() local m_pkt = comms.mgmt_packet() m_pkt.make(msg_type, msg) s_pkt.make(s_addr, self.seq_num, PROTOCOL.SCADA_MGMT, m_pkt.raw_sendable()) out_queue.push_packet(s_pkt) self.seq_num = self.seq_num + 1 end -- get an ACK status ---@nodiscard ---@param pkt rplc_frame ---@return boolean|nil ack local function _get_ack(pkt) if pkt.length == 1 then return pkt.data[1] else log.debug(log_header .. "RPLC ACK length mismatch") return nil end end -- handle a packet ---@param pkt mgmt_frame|rplc_frame local function _handle_packet(pkt) -- check sequence number if self.r_seq_num == nil then self.r_seq_num = pkt.scada_frame.seq_num() elseif (self.r_seq_num + 1) ~= pkt.scada_frame.seq_num() then log.warning(log_header .. "sequence out-of-order: last = " .. self.r_seq_num .. ", new = " .. pkt.scada_frame.seq_num()) return else self.r_seq_num = pkt.scada_frame.seq_num() end -- process packet if pkt.scada_frame.protocol() == PROTOCOL.RPLC then ---@cast pkt rplc_frame -- check reactor ID if pkt.id ~= reactor_id then log.warning(log_header .. "discarding RPLC packet with ID not matching reactor ID: reactor " .. reactor_id .. " != " .. pkt.id) return end -- feed watchdog self.conn_watchdog.feed() -- handle packet by type if pkt.type == RPLC_TYPE.STATUS then -- status packet received, update data if pkt.length >= 5 then if (type(pkt.data[1]) == "number") and (type(pkt.data[2]) == "boolean") and (type(pkt.data[3]) == "boolean") and (type(pkt.data[4]) == "boolean") and (type(pkt.data[5]) == "number") then self.sDB.last_status_update = pkt.data[1] self.sDB.control_state = pkt.data[2] self.sDB.no_reactor = pkt.data[3] self.sDB.formed = pkt.data[4] self.sDB.auto_ack_token = pkt.data[5] if (not self.sDB.no_reactor) and self.sDB.formed and (type(pkt.data[6]) == "number") then self.sDB.mek_status.heating_rate = pkt.data[6] or 0.0 -- attempt to read mek_data table if type(pkt.data[7]) == "table" then local status = pcall(_copy_status, pkt.data[7]) if status then -- copied in status data OK self.received_status_cache = true else -- error copying status data log.error(log_header .. "failed to parse status packet data") end end end else log.debug(log_header .. "RPLC status packet invalid") end else log.debug(log_header .. "RPLC status packet length mismatch") end elseif pkt.type == RPLC_TYPE.MEK_STRUCT then -- received reactor structure, record it if pkt.length == 14 then local status = pcall(_copy_struct, pkt.data) if status then -- copied in structure data OK self.received_struct = true out_queue.push_data(svqtypes.SV_Q_DATA.PLC_BUILD_CHANGED, reactor_id) else -- error copying structure data log.error(log_header .. "failed to parse struct packet data") end else log.debug(log_header .. "RPLC struct packet length mismatch") end elseif pkt.type == RPLC_TYPE.MEK_BURN_RATE then -- burn rate acknowledgement local ack = _get_ack(pkt) if ack then self.acks.burn_rate = true elseif ack == false then log.debug(log_header .. "burn rate update failed!") end -- send acknowledgement to coordinator out_queue.push_data(svqtypes.SV_Q_DATA.CRDN_ACK, { unit = reactor_id, cmd = UNIT_COMMAND.SET_BURN, ack = ack }) elseif pkt.type == RPLC_TYPE.RPS_ENABLE then -- enable acknowledgement local ack = _get_ack(pkt) if ack then self.sDB.control_state = true elseif ack == false then log.debug(log_header .. "enable failed!") end -- send acknowledgement to coordinator out_queue.push_data(svqtypes.SV_Q_DATA.CRDN_ACK, { unit = reactor_id, cmd = UNIT_COMMAND.START, ack = ack }) elseif pkt.type == RPLC_TYPE.RPS_DISABLE then -- disable acknowledgement local ack = _get_ack(pkt) if ack then self.acks.disable = true self.sDB.control_state = false elseif ack == false then log.debug(log_header .. "disable failed!") end elseif pkt.type == RPLC_TYPE.RPS_SCRAM then -- manual SCRAM acknowledgement local ack = _get_ack(pkt) if ack then self.acks.scram = true self.sDB.control_state = false elseif ack == false then log.debug(log_header .. "manual SCRAM failed!") end -- send acknowledgement to coordinator out_queue.push_data(svqtypes.SV_Q_DATA.CRDN_ACK, { unit = reactor_id, cmd = UNIT_COMMAND.SCRAM, ack = ack }) elseif pkt.type == RPLC_TYPE.RPS_ASCRAM then -- automatic SCRAM acknowledgement local ack = _get_ack(pkt) if ack then self.acks.ascram = true self.sDB.control_state = false elseif ack == false then log.debug(log_header .. " automatic SCRAM failed!") end elseif pkt.type == RPLC_TYPE.RPS_STATUS then -- RPS status packet received, copy data if pkt.length == 14 then local status = pcall(_copy_rps_status, pkt.data) if status then -- copied in RPS status data OK else -- error copying RPS status data log.error(log_header .. "failed to parse RPS status packet data") end else log.debug(log_header .. "RPLC RPS status packet length mismatch") end elseif pkt.type == RPLC_TYPE.RPS_ALARM then -- RPS alarm if pkt.length == 13 then local status = pcall(_copy_rps_status, { true, table.unpack(pkt.data) }) if status then -- copied in RPS status data OK else -- error copying RPS status data log.error(log_header .. "failed to parse RPS alarm status data") end else log.debug(log_header .. "RPLC RPS alarm packet length mismatch") end elseif pkt.type == RPLC_TYPE.RPS_RESET then -- RPS reset acknowledgement local ack = _get_ack(pkt) if ack then self.acks.rps_reset = true self.sDB.rps_tripped = false self.sDB.rps_trip_cause = "ok" elseif ack == false then log.debug(log_header .. "RPS reset failed") end -- send acknowledgement to coordinator out_queue.push_data(svqtypes.SV_Q_DATA.CRDN_ACK, { unit = reactor_id, cmd = UNIT_COMMAND.RESET_RPS, ack = ack }) elseif pkt.type == RPLC_TYPE.RPS_AUTO_RESET then -- RPS auto control reset acknowledgement local ack = _get_ack(pkt) if not ack then log.debug(log_header .. "RPS auto reset failed") end elseif pkt.type == RPLC_TYPE.AUTO_BURN_RATE then if pkt.length == 1 then local ack = pkt.data[1] if ack == PLC_AUTO_ACK.FAIL then self.acks.burn_rate = false log.debug(log_header .. "RPLC automatic burn rate set fail") elseif ack == PLC_AUTO_ACK.DIRECT_SET_OK or ack == PLC_AUTO_ACK.RAMP_SET_OK or ack == PLC_AUTO_ACK.ZERO_DIS_OK then self.acks.burn_rate = true else self.acks.burn_rate = false log.debug(log_header .. "RPLC automatic burn rate ack unknown") end else log.debug(log_header .. "RPLC automatic burn rate ack packet length mismatch") end else log.debug(log_header .. "handler received unsupported RPLC packet type " .. pkt.type) end elseif pkt.scada_frame.protocol() == PROTOCOL.SCADA_MGMT then ---@cast pkt mgmt_frame if pkt.type == MGMT_TYPE.KEEP_ALIVE then -- keep alive reply if pkt.length == 2 then local srv_start = pkt.data[1] -- local plc_send = pkt.data[2] local srv_now = util.time() self.last_rtt = srv_now - srv_start if self.last_rtt > 750 then log.warning(log_header .. "PLC KEEP_ALIVE round trip time > 750ms (" .. self.last_rtt .. "ms)") end -- log.debug(log_header .. "PLC RTT = " .. self.last_rtt .. "ms") -- log.debug(log_header .. "PLC TT = " .. (srv_now - plc_send) .. "ms") databus.tx_plc_rtt(reactor_id, self.last_rtt) else log.debug(log_header .. "SCADA keep alive packet length mismatch") end elseif pkt.type == MGMT_TYPE.CLOSE then -- close the session _close() else log.debug(log_header .. "handler received unsupported SCADA_MGMT packet type " .. pkt.type) end end end -- PUBLIC FUNCTIONS -- -- get the session ID ---@nodiscard function public.get_id() return id end -- get the session database ---@nodiscard function public.get_db() return self.sDB end -- check if ramping is completed by first verifying auto command token ack ---@nodiscard function public.is_ramp_complete() return (self.sDB.auto_ack_token == self.auto_cmd_token) and (self.commanded_burn_rate == self.sDB.mek_status.act_burn_rate) end -- get the reactor structure ---@nodiscard ---@return mek_struct|table struct struct or empty table function public.get_struct() if self.received_struct then return self.sDB.mek_struct else return {} end end -- get the reactor status ---@nodiscard ---@return mek_status|table struct status or empty table function public.get_status() if self.received_status_cache then return self.sDB.mek_status else return {} end end -- get the reactor RPS status ---@nodiscard function public.get_rps() return self.sDB.rps_status end -- get the general status information ---@nodiscard function public.get_general_status() return { self.sDB.last_status_update, self.sDB.control_state, self.sDB.rps_tripped, self.sDB.rps_trip_cause, self.sDB.no_reactor, self.sDB.formed } end -- lock out some manual operator actions during automatic control ---@param engage boolean true to engage the lockout function public.auto_lock(engage) self.auto_lock = engage -- stop retrying a burn rate command if engage then self.acks.burn_rate = true end end -- check if the manual lockout for automatic control is active function public.is_auto_locked() return self.auto_lock end -- set the burn rate on behalf of automatic control ---@param rate number burn rate ---@param ramp boolean true to ramp, false to not function public.auto_set_burn(rate, ramp) self.ramping_rate = ramp in_queue.push_data(PLC_S_DATA.AUTO_BURN_RATE, rate) end -- check if a timer matches this session's watchdog ---@nodiscard function public.check_wd(timer) return self.conn_watchdog.is_timer(timer) and self.connected end -- close the connection function public.close() _close() _send_mgmt(MGMT_TYPE.CLOSE, {}) println("connection to reactor " .. reactor_id .. " PLC closed by server") log.info(log_header .. "session closed by server") end -- iterate the session ---@nodiscard ---@return boolean connected function public.iterate() if self.connected then ------------------ -- handle queue -- ------------------ local handle_start = util.time() while in_queue.ready() and self.connected do -- get a new message to process local message = in_queue.pop() if message ~= nil then if message.qtype == mqueue.TYPE.PACKET then -- handle a packet _handle_packet(message.message) elseif message.qtype == mqueue.TYPE.COMMAND then -- handle instruction local cmd = message.message if cmd == PLC_S_CMDS.ENABLE then -- enable reactor if not self.auto_lock then _send(RPLC_TYPE.RPS_ENABLE, {}) end elseif cmd == PLC_S_CMDS.DISABLE then -- disable the reactor self.acks.disable = false self.retry_times.disable_req = util.time() + INITIAL_WAIT _send(RPLC_TYPE.RPS_DISABLE, {}) elseif cmd == PLC_S_CMDS.SCRAM then -- SCRAM reactor self.acks.scram = false self.retry_times.scram_req = util.time() + INITIAL_WAIT _send(RPLC_TYPE.RPS_SCRAM, {}) elseif cmd == PLC_S_CMDS.ASCRAM then -- SCRAM reactor self.acks.ascram = false self.retry_times.ascram_req = util.time() + INITIAL_WAIT _send(RPLC_TYPE.RPS_ASCRAM, {}) elseif cmd == PLC_S_CMDS.RPS_RESET then -- reset RPS self.acks.ascram = true self.acks.rps_reset = false self.retry_times.rps_reset_req = util.time() + INITIAL_WAIT _send(RPLC_TYPE.RPS_RESET, {}) elseif cmd == PLC_S_CMDS.RPS_AUTO_RESET then if self.sDB.rps_status.automatic or self.sDB.rps_status.timeout then _send(RPLC_TYPE.RPS_AUTO_RESET, {}) end else log.error(log_header .. "unsupported command received in in_queue (this is a bug)", true) end elseif message.qtype == mqueue.TYPE.DATA then -- instruction with body local cmd = message.message ---@type queue_data if cmd.key == PLC_S_DATA.BURN_RATE then -- update burn rate if not self.auto_lock then cmd.val = math.floor(cmd.val * 10) / 10 -- round to 10ths place if cmd.val > 0 and cmd.val <= self.sDB.mek_struct.max_burn then self.commanded_burn_rate = cmd.val self.auto_cmd_token = 0 self.ramping_rate = false self.acks.burn_rate = false self.retry_times.burn_rate_req = util.time() + INITIAL_WAIT _send(RPLC_TYPE.MEK_BURN_RATE, { self.commanded_burn_rate, self.ramping_rate }) end end elseif cmd.key == PLC_S_DATA.RAMP_BURN_RATE then -- ramp to burn rate if not self.auto_lock then cmd.val = math.floor(cmd.val * 10) / 10 -- round to 10ths place if cmd.val > 0 and cmd.val <= self.sDB.mek_struct.max_burn then self.commanded_burn_rate = cmd.val self.auto_cmd_token = 0 self.ramping_rate = true self.acks.burn_rate = false self.retry_times.burn_rate_req = util.time() + INITIAL_WAIT _send(RPLC_TYPE.MEK_BURN_RATE, { self.commanded_burn_rate, self.ramping_rate }) end end elseif cmd.key == PLC_S_DATA.AUTO_BURN_RATE then -- set automatic burn rate if self.auto_lock then cmd.val = math.floor(cmd.val * 100) / 100 -- round to 100ths place if cmd.val >= 0 and cmd.val <= self.sDB.mek_struct.max_burn then self.auto_cmd_token = util.time_ms() self.commanded_burn_rate = cmd.val -- this is only for manual control, only retry auto ramps self.acks.burn_rate = not self.ramping_rate self.retry_times.burn_rate_req = util.time() + INITIAL_AUTO_WAIT _send(RPLC_TYPE.AUTO_BURN_RATE, { self.commanded_burn_rate, self.ramping_rate, self.auto_cmd_token }) end end else log.error(log_header .. "unsupported data command received in in_queue (this is a bug)", true) end end end -- max 100ms spent processing queue if util.time() - handle_start > 100 then log.warning(log_header .. "exceeded 100ms queue process limit") break end end -- exit if connection was closed if not self.connected then println("connection to reactor " .. reactor_id .. " PLC closed by remote host") log.info(log_header .. "session closed by remote host") return self.connected end ---------------------- -- update periodics -- ---------------------- local elapsed = util.time() - self.periodics.last_update local periodics = self.periodics -- keep alive periodics.keep_alive = periodics.keep_alive + elapsed if periodics.keep_alive >= PERIODICS.KEEP_ALIVE then _send_mgmt(MGMT_TYPE.KEEP_ALIVE, { util.time() }) periodics.keep_alive = 0 end self.periodics.last_update = util.time() --------------------- -- attempt retries -- --------------------- local rtimes = self.retry_times if (not self.sDB.no_reactor) and self.sDB.formed then -- struct request retry if not self.received_struct then if rtimes.struct_req - util.time() <= 0 then _send(RPLC_TYPE.MEK_STRUCT, {}) rtimes.struct_req = util.time() + RETRY_PERIOD end end -- status cache request retry if not self.received_status_cache then if rtimes.status_req - util.time() <= 0 then _send(RPLC_TYPE.MEK_STATUS, {}) rtimes.status_req = util.time() + RETRY_PERIOD end end -- burn rate request retry if not self.acks.burn_rate then if rtimes.burn_rate_req - util.time() <= 0 then if self.auto_cmd_token > 0 then if self.auto_lock then _send(RPLC_TYPE.AUTO_BURN_RATE, { self.commanded_burn_rate, self.ramping_rate, self.auto_cmd_token }) else -- would have been an auto command, but disengaged, so stop retrying self.acks.burn_rate = true end elseif not self.auto_lock then _send(RPLC_TYPE.MEK_BURN_RATE, { self.commanded_burn_rate, self.ramping_rate }) else -- shouldn't be in this state, just pretend it was acknowledged self.acks.burn_rate = true end rtimes.burn_rate_req = util.time() + RETRY_PERIOD end end end -- reactor disable request retry if not self.acks.disable then if rtimes.disable_req - util.time() <= 0 then _send(RPLC_TYPE.RPS_DISABLE, {}) rtimes.disable_req = util.time() + RETRY_PERIOD end end -- SCRAM request retry if not self.acks.scram then if rtimes.scram_req - util.time() <= 0 then _send(RPLC_TYPE.RPS_SCRAM, {}) rtimes.scram_req = util.time() + RETRY_PERIOD end end -- automatic SCRAM request retry if not self.acks.ascram then if rtimes.ascram_req - util.time() <= 0 then _send(RPLC_TYPE.RPS_ASCRAM, {}) rtimes.ascram_req = util.time() + RETRY_PERIOD end end -- RPS reset request retry if not self.acks.rps_reset then if rtimes.rps_reset_req - util.time() <= 0 then _send(RPLC_TYPE.RPS_RESET, {}) rtimes.rps_reset_req = util.time() + RETRY_PERIOD end end end return self.connected end return public end return plc