diff --git a/doc_resources/gateway/sequence_data_collection.puml b/doc_resources/gateway/sequence_data_collection.puml
index da9ba9d..b4fdbb8 100644
--- a/doc_resources/gateway/sequence_data_collection.puml
+++ b/doc_resources/gateway/sequence_data_collection.puml
@@ -9,18 +9,28 @@ participant "Database\n(InfluxDB)" as db
 == Data collection ==
 thingy -> gw : BLE advertising packet
 
-alt UUID does not match ef680100
+alt company_id != 0xffff
     gw -> gw : discard packet
-else UUID matches
-    gw -> gw : extract raw payload
-    gw -> gw : decode_payload()
-    
-    alt unknown key or value out of range
-        gw -> gw : discard invalid value\nlog warning
-    else valid payload
-        gw -> gw : add UTC timestamp
-        gw -> broker : publish JSON\n{gateway_id}/{mac}/update
-        broker -> db : store measurement
+else company_id == 0xffff
+    gw -> gw : check payload size
+
+    alt payload size != 12 bytes
+        gw -> gw : discard packet\n(non-Thingy device)
+    else payload size == 12 bytes
+        gw -> gw : decode_payload()
+
+        alt unknown key in payload
+            gw -> gw : discard packet\nlog debug
+        else valid keys
+            alt CO2 == 0xFFFFFFFF
+                gw -> gw : discard CO2 value\n(sensor not ready)
+            end
+
+            gw -> gw : add UTC timestamp
+            gw -> broker : publish JSON\n{gateway_id}/{mac}/update
+            broker --> gw : on_publish confirmed
+            broker -> db : store measurement
+        end
     end
 end