diff --git a/coordinator/iocontrol.lua b/coordinator/iocontrol.lua
index 0d953ae..4258bc1 100644
--- a/coordinator/iocontrol.lua
+++ b/coordinator/iocontrol.lua
@@ -133,12 +133,10 @@ function iocontrol.record_builds(builds)
             -- boiler builds
             if type(build.boilers) == "table" then
                 for id, boiler in pairs(build.boilers) do
-                    unit.boiler_data_tbl[id] = {
-                        formed = boiler[2], ---@type boolean|nil
-                        build = boiler[1]   ---@type table
-                    }
+                    unit.boiler_data_tbl[id].formed = boiler[1] ---@type boolean
+                    unit.boiler_data_tbl[id].build  = boiler[2] ---@type table
 
-                    unit.boiler_ps_tbl[id].publish("formed", boiler[2])
+                    unit.boiler_ps_tbl[id].publish("formed", boiler[1])
 
                     for key, val in pairs(unit.boiler_data_tbl[id].build) do
                         unit.boiler_ps_tbl[id].publish(key, val)
@@ -149,12 +147,10 @@ function iocontrol.record_builds(builds)
             -- turbine builds
             if type(build.turbines) == "table" then
                 for id, turbine in pairs(build.turbines) do
-                    unit.turbine_data_tbl[id] = {
-                        formed = turbine[2],    ---@type boolean|nil
-                        build = turbine[1]      ---@type table
-                    }
+                    unit.turbine_data_tbl[id].formed = turbine[1]   ---@type boolean
+                    unit.turbine_data_tbl[id].build  = turbine[2]   ---@type table
 
-                    unit.turbine_ps_tbl[id].publish("formed", turbine[2])
+                    unit.turbine_ps_tbl[id].publish("formed", turbine[1])
 
                     for key, val in pairs(unit.turbine_data_tbl[id].build) do
                         unit.turbine_ps_tbl[id].publish(key, val)
@@ -290,15 +286,26 @@ function iocontrol.update_statuses(statuses)
                     end
 
                     for id, boiler in pairs(rtu_statuses.boilers) do
-                        unit.boiler_data_tbl[id].state = boiler[1]  ---@type table
-                        unit.boiler_data_tbl[id].tanks = boiler[2]  ---@type table
+                        local rtu_faulted               = boiler[1] ---@type boolean
+                        unit.boiler_data_tbl[id].formed = boiler[2] ---@type boolean
+                        unit.boiler_data_tbl[id].state  = boiler[3] ---@type table
+                        unit.boiler_data_tbl[id].tanks  = boiler[4] ---@type table
 
                         local data = unit.boiler_data_tbl[id]  ---@type boilerv_session_db
 
-                        if data.state.boil_rate > 0 then
-                            unit.boiler_ps_tbl[id].publish("computed_status", 3)    -- active
+                        unit.boiler_ps_tbl[id].publish("formed", data.formed)
+                        unit.boiler_ps_tbl[id].publish("faulted", rtu_faulted)
+
+                        if data.formed then
+                            if rtu_faulted then
+                                unit.boiler_ps_tbl[id].publish("computed_status", 4)    -- faulted
+                            elseif data.state.boil_rate > 0 then
+                                unit.boiler_ps_tbl[id].publish("computed_status", 3)    -- active
+                            else
+                                unit.boiler_ps_tbl[id].publish("computed_status", 2)    -- idle
+                            end
                         else
-                            unit.boiler_ps_tbl[id].publish("computed_status", 2)    -- idle
+                            unit.boiler_ps_tbl[id].publish("computed_status", 5)    -- not formed
                         end
 
                         for key, val in pairs(unit.boiler_data_tbl[id].state) do
@@ -322,17 +329,28 @@ function iocontrol.update_statuses(statuses)
                     end
 
                     for id, turbine in pairs(rtu_statuses.turbines) do
-                        unit.turbine_data_tbl[id].state = turbine[1]    ---@type table
-                        unit.turbine_data_tbl[id].tanks = turbine[2]    ---@type table
+                        local rtu_faulted                = turbine[1]   ---@type boolean
+                        unit.turbine_data_tbl[id].formed = turbine[2]   ---@type boolean
+                        unit.turbine_data_tbl[id].state  = turbine[3]   ---@type table
+                        unit.turbine_data_tbl[id].tanks  = turbine[4]   ---@type table
 
                         local data = unit.turbine_data_tbl[id]  ---@type turbinev_session_db
 
-                        if data.tanks.steam_fill >= 0.99 then
-                            unit.turbine_ps_tbl[id].publish("computed_status", 4)   -- trip
-                        elseif data.state.flow_rate < 100 then
-                            unit.turbine_ps_tbl[id].publish("computed_status", 2)   -- idle
+                        unit.turbine_ps_tbl[id].publish("formed", data.formed)
+                        unit.turbine_ps_tbl[id].publish("faulted", rtu_faulted)
+
+                        if data.formed then
+                            if data.tanks.energy_fill >= 0.99 then
+                                unit.turbine_ps_tbl[id].publish("computed_status", 4)   -- trip
+                            elseif rtu_faulted then
+                                unit.turbine_ps_tbl[id].publish("computed_status", 5)   -- faulted
+                            elseif data.state.flow_rate < 100 then
+                                unit.turbine_ps_tbl[id].publish("computed_status", 2)   -- idle
+                            else
+                                unit.turbine_ps_tbl[id].publish("computed_status", 3)   -- active
+                            end
                         else
-                            unit.turbine_ps_tbl[id].publish("computed_status", 3)   -- active
+                            unit.turbine_ps_tbl[id].publish("computed_status", 6)       -- not formed
                         end
 
                         for key, val in pairs(unit.turbine_data_tbl[id].state) do
diff --git a/coordinator/startup.lua b/coordinator/startup.lua
index 6740bdd..1c6b90b 100644
--- a/coordinator/startup.lua
+++ b/coordinator/startup.lua
@@ -16,7 +16,7 @@ local config       = require("coordinator.config")
 local coordinator  = require("coordinator.coordinator")
 local renderer     = require("coordinator.renderer")
 
-local COORDINATOR_VERSION = "alpha-v0.6.4"
+local COORDINATOR_VERSION = "alpha-v0.6.5"
 
 local print = util.print
 local println = util.println
diff --git a/coordinator/ui/components/boiler.lua b/coordinator/ui/components/boiler.lua
index 08cab0a..c7a1b97 100644
--- a/coordinator/ui/components/boiler.lua
+++ b/coordinator/ui/components/boiler.lua
@@ -22,7 +22,7 @@ local function new_view(root, x, y, ps)
     local text_fg_bg = cpair(colors.black, colors.lightGray)
     local lu_col = cpair(colors.gray, colors.gray)
 
-    local status = StateIndicator{parent=boiler,x=10,y=1,states=style.boiler.states,value=1,min_width=10}
+    local status = StateIndicator{parent=boiler,x=9,y=1,states=style.boiler.states,value=1,min_width=12}
     local temp   = DataIndicator{parent=boiler,x=5,y=3,lu_colors=lu_col,label="Temp:",unit="K",format="%10.2f",value=0,width=22,fg_bg=text_fg_bg}
     local boil_r = DataIndicator{parent=boiler,x=5,y=4,lu_colors=lu_col,label="Boil:",unit="mB/t",format="%10.0f",value=0,commas=true,width=22,fg_bg=text_fg_bg}
 
diff --git a/coordinator/ui/components/turbine.lua b/coordinator/ui/components/turbine.lua
index f4cbcf1..4070eb0 100644
--- a/coordinator/ui/components/turbine.lua
+++ b/coordinator/ui/components/turbine.lua
@@ -23,7 +23,7 @@ local function new_view(root, x, y, ps)
     local text_fg_bg = cpair(colors.black, colors.lightGray)
     local lu_col = cpair(colors.gray, colors.gray)
 
-    local status    = StateIndicator{parent=turbine,x=8,y=1,states=style.turbine.states,value=1,min_width=10}
+    local status    = StateIndicator{parent=turbine,x=7,y=1,states=style.turbine.states,value=1,min_width=12}
     local prod_rate = PowerIndicator{parent=turbine,x=5,y=3,lu_colors=lu_col,label="",format="%10.2f",value=0,width=16,fg_bg=text_fg_bg}
     local flow_rate = DataIndicator{parent=turbine,x=5,y=4,lu_colors=lu_col,label="",unit="mB/t",format="%10.0f",value=0,commas=true,width=16,fg_bg=text_fg_bg}
 
diff --git a/coordinator/ui/style.lua b/coordinator/ui/style.lua
index 395e6f2..ae83155 100644
--- a/coordinator/ui/style.lua
+++ b/coordinator/ui/style.lua
@@ -76,6 +76,14 @@ style.boiler = {
         {
             color = cpair(colors.black, colors.green),
             text = "ACTIVE"
+        },
+        {
+            color = cpair(colors.black, colors.orange),
+            text = "RTU  FAULT"
+        },
+        {
+            color = cpair(colors.black, colors.orange),
+            text = "NOT FORMED"
         }
     }
 }
@@ -98,6 +106,14 @@ style.turbine = {
         {
             color = cpair(colors.black, colors.red),
             text = "TRIP"
+        },
+        {
+            color = cpair(colors.black, colors.orange),
+            text = "RTU  FAULT"
+        },
+        {
+            color = cpair(colors.black, colors.orange),
+            text = "NOT FORMED"
         }
     }
 }
diff --git a/rtu/rtu.lua b/rtu/rtu.lua
index c427f54..229d58b 100644
--- a/rtu/rtu.lua
+++ b/rtu/rtu.lua
@@ -271,6 +271,12 @@ function rtu.comms(version, modem, local_port, server_port, conn_watchdog)
         _send(SCADA_MGMT_TYPES.RTU_ADVERT, advertisement)
     end
 
+    -- notify that a peripheral was remounted
+    ---@param unit_index integer RTU unit ID
+    function public.send_remounted(unit_index)
+        _send(SCADA_MGMT_TYPES.RTU_DEV_REMOUNT, { unit_index })
+    end
+
     -- parse a MODBUS/SCADA packet
     ---@param side string
     ---@param sender integer
@@ -400,6 +406,8 @@ function rtu.comms(version, modem, local_port, server_port, conn_watchdog)
                     -- acknowledgement
                     rtu_state.linked = true
                     self.r_seq_num = nil
+                    println_ts("supervisor connection established")
+                    log.info("supervisor connection established")
                 elseif packet.type == SCADA_MGMT_TYPES.RTU_ADVERT then
                     -- request for capabilities again
                     public.send_advertisement(units)
diff --git a/rtu/startup.lua b/rtu/startup.lua
index 7e6978d..6ce9ffe 100644
--- a/rtu/startup.lua
+++ b/rtu/startup.lua
@@ -24,7 +24,7 @@ local sna_rtu      = require("rtu.dev.sna_rtu")
 local sps_rtu      = require("rtu.dev.sps_rtu")
 local turbinev_rtu = require("rtu.dev.turbinev_rtu")
 
-local RTU_VERSION = "beta-v0.8.2"
+local RTU_VERSION = "beta-v0.9.0"
 
 local rtu_t = types.rtu_t
 
@@ -116,8 +116,8 @@ local function configure()
     -- redstone interfaces
     for entry_idx = 1, #rtu_redstone do
         local rs_rtu = redstone_rtu.new()
-        local io_table = rtu_redstone[entry_idx].io
-        local io_reactor = rtu_redstone[entry_idx].for_reactor
+        local io_table = rtu_redstone[entry_idx].io             ---@type table
+        local io_reactor = rtu_redstone[entry_idx].for_reactor  ---@type integer
 
         -- CHECK: reactor ID must be >= to 1
         if (not util.is_int(io_reactor)) or (io_reactor <= 0) then
@@ -218,6 +218,7 @@ local function configure()
                 index = entry_idx,
                 reactor = io_reactor,
                 device = capabilities,  -- use device field for redstone channels
+                formed = nil,       ---@type boolean|nil
                 rtu = rs_rtu,       ---@type rtu_device|rtu_rs_device
                 modbus_io = modbus.new(rs_rtu, false),
                 pkt_queue = nil,    ---@type mqueue|nil
@@ -265,26 +266,55 @@ local function configure()
             local type = ppm.get_type(name)
             local rtu_iface = nil   ---@type rtu_device
             local rtu_type = ""
+            local formed = nil      ---@type boolean|nil
 
             if type == "boilerValve" then
                 -- boiler multiblock
                 rtu_type = rtu_t.boiler_valve
                 rtu_iface = boilerv_rtu.new(device)
+                formed = device.isFormed()
+
+                if formed == ppm.UNDEFINED_FIELD or formed == ppm.ACCESS_FAULT then
+                    println_ts(util.c("configure> failed to check if  '", name, "' is formed"))
+                    log.fatal(util.c("configure> failed to check if  '", name, "' is a formed boiler multiblock"))
+                    return false
+                end
             elseif type == "turbineValve" then
                 -- turbine multiblock
                 rtu_type = rtu_t.turbine_valve
                 rtu_iface = turbinev_rtu.new(device)
+                formed = device.isFormed()
+
+                if formed == ppm.UNDEFINED_FIELD or formed == ppm.ACCESS_FAULT then
+                    println_ts(util.c("configure> failed to check if  '", name, "' is formed"))
+                    log.fatal(util.c("configure> failed to check if  '", name, "' is a formed turbine multiblock"))
+                    return false
+                end
             elseif type == "inductionPort" then
                 -- induction matrix multiblock
                 rtu_type = rtu_t.induction_matrix
                 rtu_iface = imatrix_rtu.new(device)
+                formed = device.isFormed()
+
+                if formed == ppm.UNDEFINED_FIELD or formed == ppm.ACCESS_FAULT then
+                    println_ts(util.c("configure> failed to check if  '", name, "' is formed"))
+                    log.fatal(util.c("configure> failed to check if  '", name, "' is a formed induction matrix multiblock"))
+                    return false
+                end
             elseif type == "spsPort" then
                 -- SPS multiblock
                 rtu_type = rtu_t.sps
                 rtu_iface = sps_rtu.new(device)
+                formed = device.isFormed()
+
+                if formed == ppm.UNDEFINED_FIELD or formed == ppm.ACCESS_FAULT then
+                    println_ts(util.c("configure> failed to check if  '", name, "' is formed"))
+                    log.fatal(util.c("configure> failed to check if  '", name, "' is a formed SPS multiblock"))
+                    return false
+                end
             elseif type == "solarNeutronActivator" then
                 -- SNA
-                rtu_type = rtu_t.sps
+                rtu_type = rtu_t.sna
                 rtu_iface = sna_rtu.new(device)
             elseif type == "environmentDetector" then
                 -- advanced peripherals environment detector
@@ -305,6 +335,7 @@ local function configure()
                     index = index,
                     reactor = for_reactor,
                     device = device,
+                    formed = formed,
                     rtu = rtu_iface,            ---@type rtu_device|rtu_rs_device
                     modbus_io = modbus.new(rtu_iface, true),
                     pkt_queue = mqueue.new(),   ---@type mqueue|nil
diff --git a/rtu/threads.lua b/rtu/threads.lua
index 0cfcd7a..e3d4cd7 100644
--- a/rtu/threads.lua
+++ b/rtu/threads.lua
@@ -5,7 +5,10 @@ local types         = require("scada-common.types")
 local util          = require("scada-common.util")
 
 local boilerv_rtu   = require("rtu.dev.boilerv_rtu")
+local envd_rtu      = require("rtu.dev.envd_rtu")
 local imatrix_rtu   = require("rtu.dev.imatrix_rtu")
+local sna_rtu       = require("rtu.dev.sna_rtu")
+local sps_rtu       = require("rtu.dev.sps_rtu")
 local turbinev_rtu  = require("rtu.dev.turbinev_rtu")
 
 local modbus = require("rtu.modbus")
@@ -117,20 +120,35 @@ function threads.thread__main(smem)
                             local unit = units[i]   ---@type rtu_unit_registry_entry
 
                             -- find disconnected device to reconnect
+                            -- note: cannot check isFormed as that would yield this coroutine and consume events
                             if unit.name == param1 then
                                 -- found, re-link
                                 unit.device = device
 
                                 if unit.type == rtu_t.boiler_valve then
                                     unit.rtu = boilerv_rtu.new(device)
+                                    unit.formed = true
                                 elseif unit.type == rtu_t.turbine_valve then
                                     unit.rtu = turbinev_rtu.new(device)
+                                    unit.formed = true
                                 elseif unit.type == rtu_t.induction_matrix then
                                     unit.rtu = imatrix_rtu.new(device)
+                                    unit.formed = true
+                                elseif unit.type == rtu_t.sps then
+                                    unit.rtu = sps_rtu.new(device)
+                                    unit.formed = true
+                                elseif unit.type == rtu_t.sna then
+                                    unit.rtu = sna_rtu.new(device)
+                                elseif unit.type == rtu_t.env_detector then
+                                    unit.rtu = envd_rtu.new(device)
+                                else
+                                    log.error(util.c("unreachable case occured trying to identify reconnected RTU unit type (", unit.name, ")"), true)
                                 end
 
                                 unit.modbus_io = modbus.new(unit.rtu, true)
 
+                                rtu_comms.send_remounted(unit.index)
+
                                 println_ts("reconnected the " .. unit.type .. " on interface " .. unit.name)
                             end
                         end
@@ -256,6 +274,12 @@ function threads.thread__unit_comms(smem, unit)
 
         local last_update  = util.time()
 
+        local check_formed = type(unit.formed) == "boolean"
+        local last_f_check = 0
+
+        local detail_name  = util.c(unit.type, " (", unit.name, ") [", unit.index, "] for reactor ", unit.reactor)
+        local short_name   = util.c(unit.type, " (", unit.name, ")")
+
         if packet_queue == nil then
             log.error("rtu unit thread created without a message queue, exiting...", true)
             return
@@ -283,9 +307,64 @@ function threads.thread__unit_comms(smem, unit)
                 util.nop()
             end
 
+
+            -- check if multiblocks is still formed
+            if check_formed and (util.time() - last_f_check > 1000) then
+                if (not unit.formed) and unit.device.isFormed() then
+                    -- newly re-formed
+                    local iface = ppm.get_iface(unit.device)
+                    if iface then
+                        log.info(util.c("unmounting and remounting reformed RTU unit ", detail_name))
+
+                        ppm.unmount(unit.device)
+
+                        local type, device = ppm.mount(iface)
+
+                        if device ~= nil then
+                            if type == "boilerValve" and unit.type == rtu_t.boiler_valve then
+                                -- boiler multiblock
+                                unit.device = device
+                                unit.rtu = boilerv_rtu.new(device)
+                                unit.formed = device.isFormed()
+                                unit.modbus_io = modbus.new(unit.rtu, true)
+                            elseif type == "turbineValve" and unit.type == rtu_t.turbine_valve then
+                                -- turbine multiblock
+                                unit.device = device
+                                unit.rtu = turbinev_rtu.new(device)
+                                unit.formed = device.isFormed()
+                                unit.modbus_io = modbus.new(unit.rtu, true)
+                            elseif type == "inductionPort" and unit.type == rtu_t.induction_matrix then
+                                -- induction matrix multiblock
+                                unit.device = device
+                                unit.rtu = imatrix_rtu.new(device)
+                                unit.formed = device.isFormed()
+                                unit.modbus_io = modbus.new(unit.rtu, true)
+                            elseif type == "spsPort" and unit.type == rtu_t.sps then
+                                -- SPS multiblock
+                                unit.device = device
+                                unit.rtu = sps_rtu.new(device)
+                                unit.formed = device.isFormed()
+                                unit.modbus_io = modbus.new(unit.rtu, true)
+                            else
+                                log.error("illegal remount of non-multiblock RTU attempted for " .. short_name, true)
+                            end
+
+                            rtu_comms.send_remounted(unit.index)
+                        else
+                            -- fully lost the peripheral now :(
+                            log.error(util.c(unit.name, " lost (failed reconnect)"))
+                        end
+
+                        log.info("reconnected the " .. unit.type .. " on interface " .. unit.name)
+                    else
+                        log.error("failed to get interface of previously connected RTU unit " .. detail_name, true)
+                    end
+                end
+            end
+
             -- check for termination request
             if rtu_state.shutdown then
-                log.info("rtu unit thread exiting -> " .. unit.type .. "(" .. unit.name .. ")")
+                log.info("rtu unit thread exiting -> " .. short_name)
                 break
             end
 
@@ -305,7 +384,7 @@ function threads.thread__unit_comms(smem, unit)
             end
 
             if not rtu_state.shutdown then
-                log.info(util.c("rtu unit thread ", unit.type, "(", unit.name, ") restarting in 5 seconds..."))
+                log.info(util.c("rtu unit thread ", unit.type, "(", unit.name, " restarting in 5 seconds..."))
                 util.psleep(5)
             end
         end
diff --git a/scada-common/comms.lua b/scada-common/comms.lua
index 352e77f..e4df65c 100644
--- a/scada-common/comms.lua
+++ b/scada-common/comms.lua
@@ -44,8 +44,9 @@ local RPLC_LINKING = {
 local SCADA_MGMT_TYPES = {
     KEEP_ALIVE = 0,     -- keep alive packet w/ RTT
     CLOSE = 1,          -- close a connection
-    RTU_ADVERT = 2,     -- RTU capability advertisement
-    REMOTE_LINKED = 3   -- remote device linked
+    REMOTE_LINKED = 2,  -- remote device linked
+    RTU_ADVERT = 3,     -- RTU capability advertisement
+    RTU_DEV_REMOUNT = 4 -- RTU multiblock possbily changed (formed, unformed) due to PPM remount
 }
 
 ---@alias SCADA_CRDN_TYPES integer
@@ -383,7 +384,8 @@ function comms.mgmt_packet()
         return self.type == SCADA_MGMT_TYPES.KEEP_ALIVE or
                 self.type == SCADA_MGMT_TYPES.CLOSE or
                 self.type == SCADA_MGMT_TYPES.REMOTE_LINKED or
-                self.type == SCADA_MGMT_TYPES.RTU_ADVERT
+                self.type == SCADA_MGMT_TYPES.RTU_ADVERT or
+                self.type == SCADA_MGMT_TYPES.RTU_DEV_REMOUNT
     end
 
     -- make a SCADA management packet
diff --git a/supervisor/session/rtu.lua b/supervisor/session/rtu.lua
index 1469863..ec48bc0 100644
--- a/supervisor/session/rtu.lua
+++ b/supervisor/session/rtu.lua
@@ -288,6 +288,16 @@ function rtu.new_session(id, in_queue, out_queue, advertisement, facility_units)
                 -- handle advertisement; this will re-create all unit sub-sessions
                 self.advert = pkt.data
                 _handle_advertisement()
+            elseif pkt.type == SCADA_MGMT_TYPES.RTU_DEV_REMOUNT then
+                if pkt.length == 1 then
+                    local unit_id = pkt[1]
+                    if self.units[unit_id] ~= nil then
+                        local unit = self.units[unit_id]    ---@type unit_session
+                        unit.invalidate_cache()
+                    end
+                else
+                    log.debug(log_header .. "SCADA RTU device re-mount packet length mismatch")
+                end
             else
                 log.debug(log_header .. "handler received unsupported SCADA_MGMT packet type " .. pkt.type)
             end
diff --git a/supervisor/session/rtu/boilerv.lua b/supervisor/session/rtu/boilerv.lua
index bd9aaad..8b5b02e 100644
--- a/supervisor/session/rtu/boilerv.lua
+++ b/supervisor/session/rtu/boilerv.lua
@@ -159,6 +159,8 @@ function boilerv.new(session_id, unit_id, advert, out_queue)
                 self.db.build.max_boil_rate = m_pkt.data[12]
                 self.db.build.env_loss      = m_pkt.data[13]
                 self.has_build = true
+
+                out_queue.push_command(unit_session.RTU_US_CMDS.BUILD_CHANGED)
             else
                 log.debug(log_tag .. "MODBUS transaction reply length mismatch (" .. TXN_TAGS[txn_type] .. ")")
             end
@@ -227,6 +229,13 @@ function boilerv.new(session_id, unit_id, advert, out_queue)
         self.session.post_update()
     end
 
+    -- invalidate build cache
+    function public.invalidate_cache()
+        self.periodics.next_formed_req = 0
+        self.periodics.next_build_req = 0
+        self.has_build = false
+    end
+
     -- get the unit session database
     function public.get_db() return self.db end
 
diff --git a/supervisor/session/rtu/envd.lua b/supervisor/session/rtu/envd.lua
index 3050835..a5546e4 100644
--- a/supervisor/session/rtu/envd.lua
+++ b/supervisor/session/rtu/envd.lua
@@ -94,6 +94,11 @@ function envd.new(session_id, unit_id, advert, out_queue)
         self.session.post_update()
     end
 
+    -- invalidate build cache
+    function public.invalidate_cache()
+        -- no build cache for this device
+    end
+
     -- get the unit session database
     function public.get_db() return self.db end
 
diff --git a/supervisor/session/rtu/imatrix.lua b/supervisor/session/rtu/imatrix.lua
index fc64b6d..3ebc7ab 100644
--- a/supervisor/session/rtu/imatrix.lua
+++ b/supervisor/session/rtu/imatrix.lua
@@ -142,6 +142,8 @@ function imatrix.new(session_id, unit_id, advert, out_queue)
                 self.db.build.cells        = m_pkt.data[8]
                 self.db.build.providers    = m_pkt.data[9]
                 self.has_build = true
+
+                out_queue.push_command(unit_session.RTU_US_CMDS.BUILD_CHANGED)
             else
                 log.debug(log_tag .. "MODBUS transaction reply length mismatch (" .. TXN_TAGS[txn_type] .. ")")
             end
@@ -201,6 +203,13 @@ function imatrix.new(session_id, unit_id, advert, out_queue)
         self.session.post_update()
     end
 
+    -- invalidate build cache
+    function public.invalidate_cache()
+        self.periodics.next_formed_req = 0
+        self.periodics.next_build_req = 0
+        self.has_build = false
+    end
+
     -- get the unit session database
     function public.get_db() return self.db end
 
diff --git a/supervisor/session/rtu/redstone.lua b/supervisor/session/rtu/redstone.lua
index 7ebd28b..35764ac 100644
--- a/supervisor/session/rtu/redstone.lua
+++ b/supervisor/session/rtu/redstone.lua
@@ -254,6 +254,11 @@ function redstone.new(session_id, unit_id, advert, out_queue)
         self.session.post_update()
     end
 
+    -- invalidate build cache
+    function public.invalidate_cache()
+        -- no build cache for this device
+    end
+
     -- get the unit session database
     function public.get_db() return self.db end
 
diff --git a/supervisor/session/rtu/sna.lua b/supervisor/session/rtu/sna.lua
index 68f38ae..297708a 100644
--- a/supervisor/session/rtu/sna.lua
+++ b/supervisor/session/rtu/sna.lua
@@ -112,6 +112,8 @@ function sna.new(session_id, unit_id, advert, out_queue)
                 self.db.build.input_cap   = m_pkt.data[1]
                 self.db.build.output_cap  = m_pkt.data[2]
                 self.has_build = true
+
+                out_queue.push_command(unit_session.RTU_US_CMDS.BUILD_CHANGED)
             else
                 log.debug(log_tag .. "MODBUS transaction reply length mismatch (" .. TXN_TAGS[txn_type] .. ")")
             end
@@ -167,6 +169,12 @@ function sna.new(session_id, unit_id, advert, out_queue)
         self.session.post_update()
     end
 
+    -- invalidate build cache
+    function public.invalidate_cache()
+        self.periodics.next_build_req = 0
+        self.has_build = false
+    end
+
     -- get the unit session database
     function public.get_db() return self.db end
 
diff --git a/supervisor/session/rtu/sps.lua b/supervisor/session/rtu/sps.lua
index badad45..8b42bd1 100644
--- a/supervisor/session/rtu/sps.lua
+++ b/supervisor/session/rtu/sps.lua
@@ -147,6 +147,8 @@ function sps.new(session_id, unit_id, advert, out_queue)
                 self.db.build.output_cap  = m_pkt.data[8]
                 self.db.build.max_energy  = m_pkt.data[9]
                 self.has_build = true
+
+                out_queue.push_command(unit_session.RTU_US_CMDS.BUILD_CHANGED)
             else
                 log.debug(log_tag .. "MODBUS transaction reply length mismatch (" .. TXN_TAGS[txn_type] .. ")")
             end
@@ -211,6 +213,13 @@ function sps.new(session_id, unit_id, advert, out_queue)
         self.session.post_update()
     end
 
+    -- invalidate build cache
+    function public.invalidate_cache()
+        self.periodics.next_formed_req = 0
+        self.periodics.next_build_req = 0
+        self.has_build = false
+    end
+
     -- get the unit session database
     function public.get_db() return self.db end
 
diff --git a/supervisor/session/rtu/turbinev.lua b/supervisor/session/rtu/turbinev.lua
index d30733c..2927fd2 100644
--- a/supervisor/session/rtu/turbinev.lua
+++ b/supervisor/session/rtu/turbinev.lua
@@ -198,6 +198,8 @@ function turbinev.new(session_id, unit_id, advert, out_queue)
                 self.db.build.max_production   = m_pkt.data[14]
                 self.db.build.max_water_output = m_pkt.data[15]
                 self.has_build = true
+
+                out_queue.push_command(unit_session.RTU_US_CMDS.BUILD_CHANGED)
             else
                 log.debug(log_tag .. "MODBUS transaction reply length mismatch (" .. TXN_TAGS[txn_type] .. ")")
             end
@@ -301,6 +303,13 @@ function turbinev.new(session_id, unit_id, advert, out_queue)
         self.session.post_update()
     end
 
+    -- invalidate build cache
+    function public.invalidate_cache()
+        self.periodics.next_formed_req = 0
+        self.periodics.next_build_req = 0
+        self.has_build = false
+    end
+
     -- get the unit session database
     function public.get_db() return self.db end
 
diff --git a/supervisor/session/rtu/unit_session.lua b/supervisor/session/rtu/unit_session.lua
index 3a70f26..245461e 100644
--- a/supervisor/session/rtu/unit_session.lua
+++ b/supervisor/session/rtu/unit_session.lua
@@ -11,6 +11,16 @@ local PROTOCOLS = comms.PROTOCOLS
 local MODBUS_FCODE = types.MODBUS_FCODE
 local MODBUS_EXCODE = types.MODBUS_EXCODE
 
+local RTU_US_CMDS = {
+    BUILD_CHANGED = 1
+}
+
+local RTU_US_DATA = {
+}
+
+unit_session.RTU_US_CMDS = RTU_US_CMDS
+unit_session.RTU_US_DATA = RTU_US_DATA
+
 -- create a new unit session runner
 ---@param unit_id integer MODBUS unit ID
 ---@param advert rtu_advertisement RTU advertisement for this unit
@@ -152,6 +162,11 @@ function unit_session.new(unit_id, advert, out_queue, log_tag, txn_tags)
         log.debug("template unit_session.update() called", true)
     end
 
+    -- invalidate build cache
+    function public.invalidate_cache()
+        log.debug("template unit_session.invalidate_cache() called", true)
+    end
+
     -- get the unit session database
     function public.get_db() return {} end
 
diff --git a/supervisor/session/unit.lua b/supervisor/session/unit.lua
index b8dcc03..2ad30c4 100644
--- a/supervisor/session/unit.lua
+++ b/supervisor/session/unit.lua
@@ -429,13 +429,13 @@ function unit.new(for_reactor, num_boilers, num_turbines)
         build.boilers = {}
         for i = 1, #self.boilers do
             local boiler = self.boilers[i]  ---@type unit_session
-            build.boilers[boiler.get_device_idx()] = { boiler.get_db().build, boiler.get_db().formed }
+            build.boilers[boiler.get_device_idx()] = { boiler.get_db().formed, boiler.get_db().build }
         end
 
         build.turbines = {}
         for i = 1, #self.turbines do
             local turbine = self.turbines[i]  ---@type unit_session
-            build.turbines[turbine.get_device_idx()] = { turbine.get_db().build, turbine.get_db().formed }
+            build.turbines[turbine.get_device_idx()] = { turbine.get_db().formed, turbine.get_db().build }
         end
 
         return build
@@ -461,14 +461,24 @@ function unit.new(for_reactor, num_boilers, num_turbines)
         status.boilers = {}
         for i = 1, #self.boilers do
             local boiler = self.boilers[i]  ---@type unit_session
-            status.boilers[boiler.get_device_idx()] = { boiler.get_db().state, boiler.get_db().tanks }
+            status.boilers[boiler.get_device_idx()] = {
+                boiler.is_faulted(),
+                boiler.get_db().formed,
+                boiler.get_db().state,
+                boiler.get_db().tanks
+            }
         end
 
         -- status of turbines (including tanks)
         status.turbines = {}
         for i = 1, #self.turbines do
             local turbine = self.turbines[i]  ---@type unit_session
-            status.turbines[turbine.get_device_idx()] = { turbine.get_db().state, turbine.get_db().tanks }
+            status.turbines[turbine.get_device_idx()] = {
+                turbine.is_faulted(),
+                turbine.get_db().formed,
+                turbine.get_db().state,
+                turbine.get_db().tanks
+            }
         end
 
         ---@todo other RTU statuses
diff --git a/supervisor/startup.lua b/supervisor/startup.lua
index afe2745..2459673 100644
--- a/supervisor/startup.lua
+++ b/supervisor/startup.lua
@@ -13,7 +13,7 @@ local svsessions = require("supervisor.session.svsessions")
 local config     = require("supervisor.config")
 local supervisor = require("supervisor.supervisor")
 
-local SUPERVISOR_VERSION = "beta-v0.6.8"
+local SUPERVISOR_VERSION = "beta-v0.7.0"
 
 local print = util.print
 local println = util.println