diff --git a/read_config b/read_config
index b5b0c3e..6094e0f 100755
--- a/read_config
+++ b/read_config
@@ -2,6 +2,7 @@
 # set -x
 
 source ./log_helpers
+source ./general_utils
 
 if [ ${read_config_sourced:-1} = "1" ]; then    # include only once
     readonly read_config_sourced=${BASH_SOURCE[0]}
@@ -45,6 +46,7 @@ if [ ${read_config_sourced:-1} = "1" ]; then    # include only once
         
         local readonly cf="$CONFIGFILENAME"
 
+        ### TODO: wieso wird hier in das verzeichnis gewechselt
         if cd $WORKING_DIRECTORY ; then
             log_debug "$func:${LINENO}: cd to $WORKING_DIRECTORY"
         else
@@ -52,31 +54,17 @@ if [ ${read_config_sourced:-1} = "1" ]; then    # include only once
         fi
         
         readonly GIT_SSL_NO_VERIFY="$(cat "$cf" | jq -r .GIT_SSL_NO_VERIFY)"
-        if [ -z "$GIT_SSL_NO_VERIFY" ]; then 
-            log_fatal "$func:${LINENO} GIT_SSL_NO_VERIFY not set in $cf"
-        fi
-        log_debug "$func:${LINENO}: GIT_SSL_NO_VERIFY=$GIT_SSL_NO_VERIFY"
-        log_debug "$func:${LINENO}: WORKSPACE_DIR=$WORKSPACE_DIR"
-        
-        readonly CUSTOMER_LOCATION=$(cat "$cf" | jq -r .customer_location)
-        if [ -z "$CUSTOMER_LOCATION" ]; then 
-            log_fatal "$func:${LINENO}: CUSTOMER_LOCATION not set in $cf"
-        fi
-        log_debug "$func:${LINENO}: customer-location=$CUSTOMER_LOCATION"
+        assert_s GIT_SSL_NO_VERIFY
 
-        readonly CUST_ID="$(cat "$cf" | jq -r .customer_id)"
-        if [ -z "$CUST_ID" ]; then 
-            log_fatal "$func:${LINENO} CUST_ID not set in $cf"
-        fi
-        readonly CUSTOMER_ID="customer_$CUST_ID"
-        log_debug "$func:${LINENO}: CUSTOMER-ID=$CUSTOMER_ID"
+        readonly CUSTOMER_LOCATION=$(cat "$cf" | jq -r .customer_location)
+        assert_s CUSTOMER_LOCATION
+
+        readonly CUSTOMER_ID="$(cat "$cf" | jq -r .customer_id)"
+        assert_s CUSTOMER_ID
         
-        local __r_path="$(cat "$cf" | jq -r .cust_repository_path)"
-        if [ -z "$__r_path" ]; then 
-            log_fatal "$func:${LINENO}: customer repository path not set in $cf"
-        fi
-        readonly CUSTOMER_REPOSITORY_PATH="${__r_path}/${CUSTOMER_ID}.git"
-        log_debug "$func:${LINENO}: customer-r-path=$CUSTOMER_REPOSITORY_PATH"
+        readonly CUSTOMER_REPOSITORY_PATH="$(cat "$cf" |
+                                             jq -r .cust_repository_path)"
+        assert_s CUSTOMER_REPOSITORY_PATH
 
         local __number_of_zone_groups=$(cat "$cf"    | 
                                         jq -r .zg[0] |
@@ -94,10 +82,8 @@ if [ ${read_config_sourced:-1} = "1" ]; then    # include only once
         done
 
         readonly ZONE_GROUPS=(${__zone_groups[@]})
-        log_debug "$func:${LINENO}: ZONE_GROUPS=${ZONE_GROUPS[@]}"
+        assert_a ZONE_GROUPS
 
-        log_debug "$func:${LINENO}: reading ${wd} done"
-        
         return 0
     }
 ###############################################################################
@@ -108,27 +94,24 @@ if [ ${read_config_sourced:-1} = "1" ]; then    # include only once
 
         local __customer_id_base_dir="$WORKING_DIRECTORY/${WORKSPACE_DIR}"
         readonly CUSTOMER_ID_BASE_DIR="${__customer_id_base_dir}/${CUSTOMER_ID}"
-
-        log_debug "$func:${LINENO}: CUSTOMER_ID_BASE_DIR="
-        log_debug "$func:${LINENO}:      $CUSTOMER_ID_BASE_DIR"
+        assert_d CUSTOMER_ID_BASE_DIR
 
         CUSTOMER_LOCATION_DIR="${CUSTOMER_ID_BASE_DIR}/${CUSTOMER_LOCATION}"
-
-        log_debug "$func:${LINENO}: CUSTOMER_LOCATION_DIR="
-        log_debug "$func:${LINENO}:      $CUSTOMER_LOCATION_DIR"
+        assert_d CUSTOMER_LOCATION_DIR
 
         readonly UPDATE_CONF="${CUSTOMER_LOCATION_DIR}/update.conf"
-        log_debug "$func:${LINENO}: UPDATE.CONF=$UPDATE_CONF"
+        assert_f UPDATE_CONF
         
         readonly DC="dc2c.hex"
         readonly DC_SYS_DIR="/etc/dc"
+        readonly DC_SYS_DC_FULL="${DC_SYS_DIR}/$DC"
+        assert_d DC_SYS_DIR
+        assert_f DC_SYS_DC_FULL
+
         readonly DC_DIR="${CUSTOMER_LOCATION_DIR}/dc"
         readonly DC_FULL="${DC_DIR}/$DC"
-        if [ -f "$DC_FULL" ]; then
-            log_debug "$func:${LINENO}: d2dc.hex=$DC_FULL"
-        else
-            log_fatal "$func:${LINENO}: $DC_FULL does not exist"
-        fi
+        assert_d DC_DIR
+        assert_f DC_FULL
         
         # readonly zone_groups=(${__zone_groups[@]})
         # by now (03.03.2023) there is only one zone group.
@@ -147,231 +130,115 @@ if [ ${read_config_sourced:-1} = "1" ]; then    # include only once
         done
 
         readonly CUSTOMER_BASE_DIRS=(${__customer_base_dirs[@]})
-
-        if [ ${#CUSTOMER_BASE_DIRS[@]} -eq 0 ]; then
-            log_fatal "$func:${LINENO}: CUSTOMER_BASE_DIRS empty"
-        fi
+        assert_a CUSTOMER_BASE_DIRS
 
         # TODO
         # TODO: falls mehrere gruppen/zonen auftauchen hier anpassen
         # TODO
         readonly ZONE=1
         readonly CUSTOMER_BASE_DIR="${CUSTOMER_BASE_DIRS[$ZONE]}"
-        if [ -d "$CUSTOMER_BASE_DIR" ]; then
-            log_debug "$func:${LINENO}: CUSTOMER-BASE-DIR="
-            log_debug "$func:${LINENO}:      $CUSTOMER_BASE_DIR"
-        else
-            log_fatal "$func:${LINENO}: $CUSTOMER_BASE_DIR does not exist"
-        fi
-        
-        readonly psa_config_dir="${CUSTOMER_BASE_DIR}/etc/psa_config"
-        if [ -d "$psa_config_dir" ]; then
-            log_debug "$func:${LINENO}: psa_config_dir="
-            log_debug "$func:${LINENO}:      $psa_config_dir"
-        else
-            log_fatal "$func:${LINENO}:  $psa_config_dir does not exist"
-        fi
+        assert_d CUSTOMER_BASE_DIR
+
+        readonly PSA_CONFIG_DIR="${CUSTOMER_BASE_DIR}/etc/psa_config"
+        assert_d PSA_CONFIG_DIR
+
+        readonly PSA_UPDATE_DIR="${CUSTOMER_BASE_DIR}/etc/psa_update"
+        assert_d PSA_UPDATE_DIR
 
-        readonly psa_update_dir="${CUSTOMER_BASE_DIR}/etc/psa_update"
-        if [ -d "$psa_update_dir" ]; then
-            log_debug "$func:${LINENO}: psa_update_dir="
-            log_debug "$func:${LINENO}:      $psa_update_dir"
-        else
-            log_fatal "$func:${LINENO}:  $psa_update_dir does not exist"
-        fi
-       
         readonly ATB_SYS_DIR="/etc/atb" 
+        assert_d ATB_SYS_DIR
+
         readonly PSA_ATB_SYS_DIR="${CUSTOMER_BASE_DIR}${ATB_SYS_DIR}"
-        if [ -d "$PSA_ATB_SYS_DIR" ]; then
-            log_debug "$func:${LINENO}: PSA_ATB_SYS_DIR=$PSA_ATB_SYS_DIR"
-        else
-            log_fatal "$func:${LINENO}:  $PSA_ATB_SYS_DIR does not exist"
-        fi
+        assert_d PSA_ATB_SYS_DIR
+
+        readonly PSA_BASE_INI_DIR="${CUSTOMER_BASE_DIR}/opt/app"
+        assert_d PSA_BASE_INI_DIR
 
-        readonly psa_base_ini_dir="${CUSTOMER_BASE_DIR}/opt/app"
-        if [ -d "$psa_base_ini_dir" ]; then
-            log_debug "$func:${LINENO}: psa_base_ini_dir="
-            log_debug "$func:${LINENO}:      $psa_base_ini_dir"
-        else
-            log_fatal "$func:${LINENO}: $psa_base_ini_dir does not exist"
-        fi
-        
         readonly SYSCONFIG_SYS_DIR="/opt/app/sysconfig"
-        readonly PSA_SYSCONFIG_DIR="$CUSTOMER_BASE_DIR$SYSCONFIG_SYS_DIR"
-        # if [ -d "$psa_syconfig_dir" ]; DOES NOT WORK !!!
-        if ls -al $PSA_SYSCONFIG_DIR > /dev/null; then
-            log_debug "$func:${LINENO}: PSA_SYSCONFIG_DIR="
-            log_debug "$func:${LINENO}:      $PSA_SYSCONFIG_DIR"
-        else
-            log_error "$func:${LINENO}: $PSA_SYSCONFIG_DIR does not exist"
-        fi
+        assert_d SYSCONFIG_SYS_DIR
 
-        readonly psa_ismasmgr_dir="${psa_base_ini_dir}/ISMASMgr"
-        if [ -d "$psa_ismasmgr_dir" ]; then
-            log_debug "$func:${LINENO}: psa_ismasmgr_dir="
-            log_debug "$func:${LINENO}:      $psa_ismasmgr_dir"
-        else
-            log_fatal "$func:${LINENO}: $psa_ismasmgr_dir does not exist"
-        fi
+        readonly PSA_SYSCONFIG_DIR="${CUSTOMER_BASE_DIR}${SYSCONFIG_SYS_DIR}"
+        assert_d PSA_SYSCONFIG_DIR
+
+        readonly PSA_ISMASMGR_DIR="${PSA_BASE_INI_DIR}/ISMASMgr"
+        assert_d PSA_ISMASMGR_DIR
 
         readonly CONF_SYS_DIR="/etc/psa_config"
+        assert_d CONF_SYS_DIR
+
         readonly OPKG_SYS_DIR="/etc/psa_update"
-        readonly ATBAPP_SYS_DIR="/opt/app/ATBAPP"
+        assert_d OPKG_SYS_DIR
         
-        readonly psa_atbqt_dir="$CUSTOMER_BASE_DIR$ATBAPP_SYS_DIR"
-        if [ -d "$psa_atbqt_dir" ]; then
-            log_debug "$func:${LINENO}: psa_atbqt_dir="
-            log_debug "$func:${LINENO}:      $psa_atbqt_dir"
-        else
-            log_fatal "$func:${LINENO}: $psa_atbqt_dir does not exist"
-        fi
+        readonly ATBAPP_SYS_DIR="/opt/app/ATBAPP"
+        assert_d ATBAPP_SYS_DIR
+        
+        readonly PSA_ATBQT_DIR="$CUSTOMER_BASE_DIR$ATBAPP_SYS_DIR"
+        assert_d PSA_ATBQT_DIR
 
         readonly TARIFF_CURRENT="tariff.current"
-        readonly TARIFF_CURRENT_FULL="${psa_atbqt_dir}/$TARIFF_CURRENT"
-        if [ -f "$TARIFF_CURRENT_FULL" ]; then
-            log_debug "$func:${LINENO}: tariff.current="
-            log_debug "$func:${LINENO}:      $TARIFF_CURRENT_FULL"
-        else
-            log_fatal "$func:${LINENO}: $TARIFF_CURRENT_FULL does not exist"
-        fi
+        readonly TARIFF_CURRENT_FULL="${PSA_ATBQT_DIR}/$TARIFF_CURRENT"
+        assert_f TARIFF_CURRENT_FULL
 
         readonly ATBQT_INI="ATBQT.ini"
-        readonly ATBQT_INI_FULL="${psa_atbqt_dir}/$ATBQT_INI"
-        if [ -f "$ATBQT_INI_FULL" ]; then
-            log_debug "$func:${LINENO}: ATBTQT.ini="
-            log_debug "$func:${LINENO}:      $ATBQT_INI_FULL"
-        else
-            log_fatal "$func:${LINENO}: $ATBQT_INI_FULL does not exist"
-        fi
+        readonly ATBQT_INI_FULL="${PSA_ATBQT_DIR}/$ATBQT_INI"
+        assert_f ATBQT_INI_FULL
         
         readonly ATBQT="ATBQT"
         readonly ATBQT_SYS_FULL="${ATBAPP_SYS_DIR}/$ATBQT"
-        if [ -f "$ATBQT_SYS_FULL" ]; then
-            log_debug "$func:${LINENO}: ATBQT="
-            log_debug "$func:${LINENO}:      $ATBQT_SYS_FULL"
-        else
-            log_fatal "$func:${LINENO}: $ATBQT_SYS_FULL does not exist"
-        fi
+        assert_f ATBQT_SYS_FULL
        
         readonly ISMASMGR_INI="ISMASMgr.ini"
         readonly ISMASMGR_SYS_DIR="/opt/app/ISMASMgr"
+        assert_d ISMASMGR_SYS_DIR
 
-        readonly ISMASMGR_ISMASMGR_INI_FULL="${psa_ismasmgr_dir}/$ISMASMGR_INI"
-        if [ -f "$ISMASMGR_ISMASMGR_INI_FULL" ]; then
-            log_debug "$func:${LINENO}: ismasmgr_ismasmgr.ini="
-            log_debug "$func:${LINENO}:      $ISMASMGR_ISMASMGR_INI_FULL"
-        else
-            log_fatal "$func:${LINENO}: $ISMASMGR_ISMASMGR_INI_FULL "\
-                "does not exist"
-        fi
+        readonly ISMASMGR_ISMASMGR_INI_FULL="${PSA_ISMASMGR_DIR}/$ISMASMGR_INI"
+        assert_f ISMASMGR_ISMASMGR_INI_FULL
 
         readonly SYSCONFIG_ISMASMGR_INI_FULL="${PSA_SYSCONFIG_DIR}/ISMASMgr.ini"
-        if [ -f "$SYSCONFIG_ISMASMGR_INI_FULL" ]; then
-            log_debug "$func:${LINENO}: sysconfig_ismasmgr.ini="
-            log_debug "$func:${LINENO}:      $SYSCONFIG_ISMASMGR_INI_FULL"
-        else
-            log_fatal "$func:${LINENO}: $SYSCONFIG_ISMASMGR_INI_FULL "\
-                    "does not exist"
-        fi
+        assert_f SYSCONFIG_ISMASMGR_INI_FULL
 
         readonly ATB_ISMASMGR_INI_FULL="${PSA_ATB_SYS_DIR}/$ISMASMGR_INI"
-        if [ -f "$ATB_ISMASMGR_INI_FULL" ]; then
-            log_debug "$func:${LINENO}: atb_ismasmgr.ini="
-            log_debug "$func:${LINENO}:      $ATB_ISMASMGR_INI_FULL"
-        else
-            log_fatal "$func:${LINENO}: $ATB_ISMASMGR_INI_FULL does not exist"
-        fi
+        assert_f ATB_ISMASMGR_INI_FULL
 
         readonly SYS_CONFIG_INI="sysconfig.ini"
         readonly __sysc_sysc_full="${PSA_SYSCONFIG_DIR}/$SYS_CONFIG_INI"
         readonly SYSCONFIG_SYSCONFIG_INI_FULL="$__sysc_sysc_full"
-        if [ -f "$SYSCONFIG_SYSCONFIG_INI_FULL" ]; then
-            log_debug "$func:${LINENO}: sysconfig_sysconfig.ini="
-            log_debug "$func:${LINENO}:      $SYSCONFIG_SYSCONFIG_INI_FULL"
-        else
-            log_fatal "$func:${LINENO}: "\
-                "$SYSCONFIG_SYSCONFIG_INI_FULL does not exist"
-        fi
-        
+        assert_f SYSCONFIG_SYSCONFIG_INI_FULL
+
         readonly ATB_SYSCONFIG_INI_FULL="${PSA_ATB_SYS_DIR}/$SYS_CONFIG_INI"
-        if [ -f "$ATB_SYSCONFIG_INI_FULL" ]; then
-            log_debug "$func:${LINENO}: atb_sysconfig.ini="
-            log_debug "$func:${LINENO}:      $ATB_SYSCONFIG_INI_FULL"
-        else
-            log_fatal "$func:${LINENO}: $ATB_SYSCONFIG_INI_FULL does not exist"
-        fi
+        assert_f ATB_SYSCONFIG_INI_FULL
 
         readonly "SYSTEM_CONTROL_INI"="SystemControl.ini"
         local __sysctrl_ini_full="${PSA_SYSCONFIG_DIR}/$SYSTEM_CONTROL_INI"
         readonly SYSCONFIG_SYSCTRL_INI_FULL="$__sysctrl_ini_full"
-        if [ -f "$SYSCONFIG_SYSCTRL_INI_FULL" ]; then
-            log_debug "$func:${LINENO}: sysconfig_systemcontrol.ini="
-            log_debug "$func:${LINENO}:      $SYSCONFIG_SYSCTRL_INI_FULL"
-        else
-            log_fatal "$func:${LINENO}: $SYSCONFIG_SYSCTRL_INI_FULL does not exist"
-        fi
-        
+        assert_f SYSCONFIG_SYSCTRL_INI_FULL
+
         readonly ATB_SYSCTRL_INI_FULL="${PSA_ATB_SYS_DIR}/$SYSTEM_CONTROL_INI"
-        if [ -f "$ATB_SYSCTRL_INI_FULL" ]; then
-            log_debug "$func:${LINENO}: atb_systemcontrol.ini="
-            log_debug "$func:${LINENO}:      $ATB_SYSCTRL_INI_FULL"
-        else
-            log_fatal "$func:${LINENO}: $ATB_SYSCTRL_INI_FULL does not exist"
-        fi
-        
+        assert_f ATB_SYSCTRL_INI_FULL
+
         readonly ATB_ATBQT_INI_FULL="${PSA_ATB_SYS_DIR}/$ATBQT_INI"
-        if [ -f "$ATB_ATBQT_INI_FULL" ]; then
-            log_debug "$func:${LINENO}: ATBQT.ini="
-            log_debug "$func:${LINENO}:      $ATB_ATBQT_INI_FULL"
-        else
-            log_fatal "$func:${LINENO}: $ATB_ATBQT_INI_FULL does not exist"
-        fi
+        assert_f ATB_ATBQT_INI_FULL
 
-        readonly DC2C_SERIAL_JSON="${psa_config_dir}/DC2C_serial.json"
-        if [ -f "$DC2C_SERIAL_JSON" ]; then
-            log_debug "$func:${LINENO}: DC2C_SERIAL_JSON="
-            log_debug "$func:${LINENO}:      $DC2C_SERIAL_JSON"
-        else
-            log_fatal "$func:${LINENO}: $DC2C_SERIAL_JSON does not exist"
-        fi
+        readonly DC2C_SERIAL_JSON="${PSA_CONFIG_DIR}/DC2C_serial.json"
+        assert_f DC2C_SERIAL_JSON
 
-        readonly DC2C_CASH_JSON="${psa_config_dir}/DC2C_cash.json"
-        if [ -f "$DC2C_CASH_JSON" ]; then
-            log_debug "$func:${LINENO}: DC2C_CASH_JSON="
-            log_debug "$func:${LINENO}:      $DC2C_CASH_JSON"
-        else
-            log_debug "$func:${LINENO}: $DC2C_CASH_JSON does not exist"
-        fi
-        
-        readonly DC2C_CONF_JSON="${psa_config_dir}/DC2C_conf.json"
-        if [ -f "$DC2C_CONF_JSON" ]; then
-            log_debug "$func:${LINENO}: DC2C_CONF_JSON="
-            log_debug "$func:${LINENO}:      $DC2C_CONF_JSON"
-        else
-            log_fatal "$func:${LINENO}: $DC2C_CONF_JSON does not exist"
-        fi
+        readonly DC2C_CASH_JSON="${PSA_CONFIG_DIR}/DC2C_cash.json"
+        assert_f DC2C_CASH_JSON
+
+        readonly DC2C_CONF_JSON="${PSA_CONFIG_DIR}/DC2C_conf.json"
+        assert_f DC2C_CONF_JSON
 
         local DC2C_PRINT_JSON=()
         for i in {1..32}; do    # up to 32 print-json-files
-            local __f=${psa_config_dir}/DC2C_print$(printf "%02d" $i).json
+            local __f=${PSA_CONFIG_DIR}/DC2C_print$(printf "%02d" $i).json
             readonly DC2C_PRINT$(printf "%02d" $i)_JSON=$__f
             # local __g=$(eval echo '$'DC2C_PRINT$(printf "%02d" $i)_JSON)
-            if [ -f $__f ]; then
-                log_debug "$func:${LINENO}: DC2C_PRINT$(printf "%02d" $i)_JSON="
-                log_debug "$func:${LINENO}:      $__f"
-            else
-                log_fatal "$func:${LINENO}: $__f does not exist"
-           fi
-           DC2C_PRINT_JSON+=($__f)
+            assert_f DC2C_PRINT$(printf "%02d" $i)_JSON
+            DC2C_PRINT_JSON+=($__f)
         done
 
-        readonly opkg_cmds_file="${psa_update_dir}/opkg_commands"
-        if [ -f "$opkg_cmds_file" ]; then
-            log_debug "$func:${LINENO}: opkg_commands="
-            log_debug "$func:${LINENO}:      $opkg_cmds_file"
-        else
-            log_fatal "$func:${LINENO}: $opkg_cmds_file does not exist"
-        fi
+        readonly OPKG_CMDS_FILE="${PSA_UPDATE_DIR}/opkg_commands"
+        assert_f OPKG_CMDS_FILE
 
         # TODO: anpassen, da z.B. fuer szeged mehrere zonen vorhanden sind
         readonly KNOWN_CONF_FILES=(${CUSTOMER_LOCATION}/update.conf         \
@@ -392,14 +259,14 @@ if [ ${read_config_sourced:-1} = "1" ]; then    # include only once
         
         readonly KNOWN_FILES=(${KNOWN_CONF_FILES[@]} \
                               ${KNOWN_INI_FILES[@]}  \
-                              ${opkg_cmds_file##*${CUSTOMER_ID}/})
+                              ${OPKG_CMDS_FILE##*${CUSTOMER_ID}/})
 
-        log_debug "$func:${LINENO}: known conf/ini_files ->"
+        log_debug "known conf/ini_files ->"
         for (( i=0; i < ${#KNOWN_FILES[@]}; ++i )); do
             tab=$'\t'
-            log_debug "$func:${LINENO}: $tab$tab ${KNOWN_FILES[$i]}"
+            log_debug "$tab$tab ${KNOWN_FILES[$i]}"
         done
-        log_debug "$func:${LINENO}: sanity of ${CUSTOMER_REPOSITORY_PATH} OK"
+        log_debug "sanity of ${CUSTOMER_REPOSITORY_PATH} OK"
 
         return 0
     }