openhab · J-N-K · Dec 13, 2023 · Dec 10, 2023 · Dec 11, 2023 · Dec 12, 2023
@@ -235,18 +235,23 @@ For UoM support see the explanations of the `number` channel.
 #### Group Address Notation
 
 ```text
-<config>="[<dpt>:][<]<mainGA>[[+[<]<listeningGA>][+[<]<listeningGA>..]]"
+<config>="[<dpt>:][<>]<mainGA>[[+[<]<listeningGA>][+[<]<listeningGA>..]]"
 ```
 
 where parts in brackets `[]` denote optional information.
 
+**Each configuration parameter has a `mainGA` where commands are written to and optionally several `listeningGA`s.**
+
+`mainGA` also listens to incoming packets, unless prefixed with a `>` character.
+This is recommended if you have a dedicated status group address which is added as `listeningGA`.
+
 The optional `<` sign tells whether the group address of the datapoint accepts read requests on the KNX bus (it does, if the sign is there).
-All group addresses marked with `<` are read by openHAB during startup.
+The group addresses marked with `<` are read by openHAB during startup. 
+Future versions might support reading from one GA only.
 With `*-control` channels, the state is not owned by any device on the KNX bus, therefore no read requests will be sent by the binding, i.e. `<` signs will be ignored for them.
 
-Each configuration parameter has a `mainGA` where commands are written to and optionally several `listeningGA`s.
-
-The `dpt` element is optional. If omitted, the corresponding default value will be used (see the channel descriptions above).
+The element `dpt` is  highly recommended and may change to a mandatory element in future versions.
+If omitted, the corresponding default value will be used (see the channel descriptions above).
 
 ## KNX Secure
 

@@ -28,15 +28,15 @@
 /**
  * Data structure representing the content of a channel's group address configuration.
  *
- * @author Simon Kaufmann - initial contribution and API.
+ * @author Simon Kaufmann - Initial contribution and API
  *
  */
 @NonNullByDefault
 public class GroupAddressConfiguration {
     public static final Logger LOGGER = LoggerFactory.getLogger(GroupAddressConfiguration.class);
 
     private static final Pattern PATTERN_GA_CONFIGURATION = Pattern.compile(
-            "^((?<dpt>[1-9][0-9]{0,2}\\.[0-9]{3,5}):)?(?<read><)?(?<mainGA>[0-9]{1,5}(/[0-9]{1,4}){0,2})(?<listenGAs>(\\+(<?[0-9]{1,5}(/[0-9]{1,4}){0,2}))*)$");
+            "^((?<dpt>[1-9][0-9]{0,2}\\.[0-9]{3,5}):)?(?<modifier>[<>])?(?<mainGA>[0-9]{1,5}(/[0-9]{1,4}){0,2})(?<listenGAs>(\\+(<?[0-9]{1,5}(/[0-9]{1,4}){0,2}))*)$");
     private static final Pattern PATTERN_LISTEN_GA = Pattern
             .compile("\\+((?<read><)?(?<GA>[0-9]{1,5}(/[0-9]{1,4}){0,2}))");
 
@@ -57,14 +57,28 @@ private GroupAddressConfiguration(@Nullable String dpt, GroupAddress mainGA, Set
         return dpt;
     }
 
+    /**
+     * Returns the main GA, which is the GA to send commands to.
+     */
     public GroupAddress getMainGA() {
         return mainGA;
     }
 
+    /**
+     * Returns all GAs to listen to.
+     * This includes the main GA (unless disabled by '>'), and additional listening GAs
+     * (those after the "+" symbol).
+     */
     public Set<GroupAddress> getListenGAs() {
         return listenGAs;
     }
 
+    /**
+     * Returns all GAs to read from.
+     * Those GAs accept read requests to the KNX bus, i.e. they respond to a "GroupValueRead" with a
+     * "GroupValueResponse".
+     * The '&lt;' sign sets a GA as read GA.
+     */
     public Set<GroupAddress> getReadGAs() {
         return readGAs;
     }
@@ -99,9 +113,20 @@ public Set<GroupAddress> getReadGAs() {
             String mainGA = matcher.group("mainGA");
             try {
                 GroupAddress groupAddress = new GroupAddress(mainGA);
-                listenGAs.add(groupAddress); // also listening to main GA
-                if (matcher.group("read") != null) {
-                    readGAs.add(groupAddress); // also reading main GA
+                @Nullable
+                String modifier = matcher.group("modifier");
+                if (modifier == null) {
+                    // default: main GA address writes and listens
+                    listenGAs.add(groupAddress);
+                } else if ("<".equals(modifier)) {
+                    // configured for read at startup
+                    listenGAs.add(groupAddress);
+                    readGAs.add(groupAddress);
+                } // else (">").equals(modifier) -> write only, no action
+                if (readGAs.size() > 1) {
+                    LOGGER.info(
+                            "Item with mainGA {} has more than one GA configured for read at startup, check configuration",
+                            groupAddress);
                 }
                 return new GroupAddressConfiguration(matcher.group("dpt"), groupAddress, listenGAs, readGAs);
             } catch (KNXFormatException e) {

@@ -428,12 +428,15 @@ private void processDataReceived(GroupAddress destination, byte[] asdu, InboundS
                     }
                 } else {
                     if (value instanceof Command command) {
-                        logger.trace("processDataReceived postCommand new value '{}' for GA '{}'", asdu, address);
+                        logger.trace("processDataReceived postCommand to channel '{}' new value '{}' for GA '{}'",
+                                channelUID, asdu, destination);
                         postCommand(channelUID, command);
                     }
                 }
             } else {
                 if (value instanceof State state && !(value instanceof UnDefType)) {
+                    logger.trace("processDataReceived updateState to channel '{}' new value '{}' for GA '{}'",
+                            knxChannel.getChannelUID(), value, destination);
                     updateState(knxChannel.getChannelUID(), state);
                 }
             }