diff --git a/update_psa_impl b/update_psa_impl
index 95b0e30..781d725 100755
--- a/update_psa_impl
+++ b/update_psa_impl
@@ -9,12 +9,17 @@ source ./news_to_ismas
 source ./news_from_ismas
 
 update_psa() {
+
+    if ! updates_available; then    # check for false alarm
+        update_psa_false_alarm "update requested, but no WAIT state detected"
+        exit $?
+    fi
+
+    update_psa_activated    # message to ISMAS
+            
     local try_update_count=0
     local func="${FUNCNAME[0]}"
 
-    # read config parameters
-    # read_config
-                
     log_debug "$func:${LINENO}: fetch/merge updates..."
    
     # Fetch new updates (using git)
@@ -25,27 +30,38 @@ update_psa() {
             if [ "$repository_is_already_up_to_date" = "yes" ]; then
                 log_error "$func:${LINENO}: $customer_id is up-to-date"\
                     "-> no files to update -> no psa update"
-                exit 1
+                update_psa_false_alarm \
+                    "update request, but no change in $CUSTOMER_REPOSITORY_PATH"
+                exit $?
             fi
             try_updates_count=$((try_updates_count+1))
             if [[ "$try_updates_count" -eq 5 ]]; then
-                log_error "$func:${LINENO}: fetch/merging failed" ; exit 1
+                log_error "$func:${LINENO}: fetch/merging failed"
+                update_psa_pull_error # message to ISMAS
+                exit $?
             fi
-            sleep 60s
+            update_psa_pull_error # message to ISMAS
+            sleep 10s
         else
             # Fetched updates successfully 
             try_updates_count=0
             break
         fi
     done
+            
+    update_psa_pull_customer_repository # message to ISMAS
 
     # TODO: backup implementieren
     # Backup before any updates in case some previous test was wrong
     if ! backup_previous_version; then
         log_error "$func:${LINENO}: backup failed"
-        revert_customer_repository ; exit 1
+        revert_customer_repository
+        update_psa_backup_error  # message to ISMAS
+        exit $?
     fi
-                    
+    
+    update_psa_backup   # message to ISMAS
+
     # TODO: use CLONE_CUSTOMER_REPOSITORY=true
     # d.h. wird das rep geklont, also neu angelegt, dann sind eigentlich alle
     # dateinen zu ueberpruefen
@@ -53,17 +69,30 @@ update_psa() {
     local changed_files=$(changed_file_names)
     local conf_ini_files=$(filter_conf_ini_files "$changed_files")
 
+    update_psa_report_changed_file_names $changed_files # message to ISMAS
+
     # check if *.conf and/or *.ini-files have to md5-sum as denoted
     # in update.conf
     if ! check_md5_for_changed_conf_and_ini_files "$conf_ini_files" ; then
+        local __r=$?
         log_error "$func:${LINENO}: new customer files wrong"
-        revert_customer_repository ; exit 1
+        revert_customer_repository
+        exit $__r
     fi
     
+    if ! check_hardware_compatibility "$conf_ini_files" ; then
+        local __r=$?
+        log_error "$func:${LINENO}: conf/ini-files not fit for PSA"
+        revert_customer_repository
+        exit $__r
+    fi
+
     # copy *.conf and/or *.ini-files to their corresponding system-directories
     if ! copy $conf_ini_files; then
+        local __r=$?
         log_error "$func:${LINENO}: copy operation failed"
-        revert_customer_repository ; exit 1
+        revert_customer_repository
+        exit $__r
     fi
 
     # check if the opkg-command-file has been changed during 'git pull'
@@ -109,13 +138,24 @@ update_psa() {
             fi
         done
     else
-        log_info "$func:${LINENO}: no opkg commnds to execute"
+        log_info "$func:${LINENO}: no opkg commands to execute"
+        update_psa_install_opkg_packages $UPDATE_ISMAS_PROGRESS \
+                $RC_SUCCESS "no opkg commands to execute"
     fi
     
     # Cleanup.
     if ! cleanup_previous_version; then
         log_error "$func:${LINENO}: cleanup_previous_version failed"
     fi
+        
+    update_psa_cleanup $UPDATE_ISMAS_PROGRESS \
+        $RC_SUCCESS "cleanup after psa update"
+    
+    update_psa_update_succeeded $UPDATE_SUCCEEDED \
+        $RC_SUCCESS "psa update succeeded"
+    
+    update_psa_update_succeeded $UPDATE_ACTIVATED \
+        $RC_SUCCESS "psa update activated"
             
     log_info "$func:${LINENO}: success"
     exit 0