Differences

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--- carel [2020/12/23 16:50] – emozolyak
+++ carel [2022/01/15 17:31] (current) – ↷ Links adapted because of a move operation 127.0.0.1
@@ Line 1: / Line 1: @@
 ====== Carel cooling controllers ======
-{{ ::carel_-_easy-cool.png?direct&300|}}
+{{ network:carel_-_easy-cool.png?direct&300|}}
+New models Carel cooling controllers have Modbus RTU, while older models have a proprietary Carel communication protocol. The protocol is quite efficient one, becuase it only sends changes of its parameter, or "no changes" telegram. So the host syncronize its variable once and then gets updates.
+Older controllers have the following communication features:
+The modules often do not have an integrated RS-485 driver, and the connection must be made to the TTL serial bus port via TTL-RS485 converter. The default transmission format - 19200, 8 data bits, no parity, 2 stop bits.
+These modules can be read with the [[custom_protocols?s[]=custom | custom protocol]]. Turn to your local representative for more details.
+<code lua -example.lua>
+function readRegister (reg, device, unitId)
+   if not carel.synced then
+                                            DEBUG("Trying to sync, packet #1...")
+       local newId = unitId + ADDR_OFFSET
+       carel.pollTemplate[2] = newId
+       makeSync(carel.syncTemplate, newId)
+       local reply = readUntil(ETX, true)
+       if reply then
+           hexPrint(reply)
+           if (#reply > 30) then
+               DEBUG("Sync 1 done!")
+               -- now 2nd sync
+               makeSync(carel.sync2_Tmpl, newId)
+               reply = readUntil(ACK, false)
+               if reply then
+                   hexPrint(reply)       ; DEBUG("sync 2 ok!")
+                   carel.synced = true
+               end
+           end
+        end
+   end
+   if carel.synced then  -- synced
+      local poll_counter, POLL_LIMIT = 0, 40
+      repeat
+          poll_counter = poll_counter + 1
+          sendBytes(carel.pollTemplate) ; local reply = readUntil(ETX, true)
+          if not reply then
+              ERROR("could not receive reply from device...")
+              carel.synced = false
+              return false
+          end
+          if (reply[1] == NULL) then
+                                            DEBUG("Got NULL! - no changes")
+              sendBytes{ACK}
+              break
+          else
+                                            DEBUG("Normal sequence, got something!")
+              sendBytes{ACK}
+              local idx = {type = 3, addr_hi = 4, addr_lo = 5, data_start = 6}
+              local type_ = string.char(reply[idx.type]) ; DEBUG("type = " .. type_)
+              if not (type_ == 'B' or type_ == 'U' or type_ == 'S') then
+                                            ERROR("Unknown type of the device!")
+                  return -1
+              else
+                  local dev_addr = getHexFromASCII(reply[idx.addr_hi], reply[idx.addr_lo])
+                  dev_addr = string.sub(dev_addr, 1, -2)
+                  dev_addr = tonumber(dev_addr, 16) ; DEBUG("dev_addr detected = " .. dev_addr)
+                  local dev_data_len = ((type_ == 'B' and 2) or 4)
+                  local tmp_t = {}
+                  for j = idx.data_start, idx.data_start + dev_data_len - 1 do
+                      table.insert(tmp_t, string.char(reply[j]))
+                  end
+                  local dev_data = tonumber(table.concat(tmp_t), 16)
+                  DEBUG('dev type  addr data = ' .. type_ .. ' ' .. sf("%X", dev_addr) .. ' ' .. sf("%X", dev_data))
+                  carel.data[type_][dev_addr] = dev_data
+              end
+        end
+      if (poll_counter >= POLL_LIMIT) then
+         DEBUG("Poll counter finish!")
+      end
+      until (poll_counter >= POLL_LIMIT)
+    local value = carel.data[device.name][reg.internalAddr]
+    return value
+   end -- synced
+end -- readRegister
+</code>