diff --git a/check_snmp_data b/check_snmp_data
index 90ec912d4e02aff9ddccc4eb3e3494409822c780..8a8aedc234168ed4b9bcdc5bf6592cf1461708b3 100755
--- a/check_snmp_data
+++ b/check_snmp_data
@@ -2,7 +2,6 @@
 # ======================================================================
 #
 # NAGIOS / ICINGA CHECK :: check_snmp_data
-# this plugin checks snmp performance data
 #
 # DOCS:
 #   - Synology - see docs:
@@ -16,41 +15,53 @@
 # label    --> DATA:[method]:label:[text]
 # n x data --> DATA:[method]:data:[perf-label]:[oid]:[optional unit]:[loop oid]
 #
+# ---------- General infos for all devices:
+#
+# DATA:about:label:About... general device infos
+# DATA:about:out:text:sysDescr:1.3.6.1.2.1.1.1.0:
+# DATA:about:out:text:sysObjectID:1.3.6.1.2.1.1.2.0:
+# DATA:about:out:text:sysUpTime:1.3.6.1.2.1.1.3.0:
+# DATA:about:out:text:sysContact:1.3.6.1.2.1.1.4.0:
+# DATA:about:out:text:sysName:1.3.6.1.2.1.1.5.0:
+# DATA:about:out:text:sysLocation:1.3.6.1.2.1.1.6.0:
+#
 # DATA:cpu:label:CPU usage
-# DATA:cpu:data:cpu-user:1.3.6.1.4.1.2021.11.9.0:%
-# DATA:cpu:data:cpu-system:1.3.6.1.4.1.2021.11.10.0:%
-# DATA:cpu:data:cpu-idle:1.3.6.1.4.1.2021.11.11.0:%
+# DATA:cpu:out:data:cpu-user:1.3.6.1.4.1.2021.11.9.0:%
+# DATA:cpu:out:data:cpu-system:1.3.6.1.4.1.2021.11.10.0:%
+# DATA:cpu:out:data:cpu-idle:1.3.6.1.4.1.2021.11.11.0:%
 #
 # DATA:load:label:System load
-# DATA:load:data:load1:1.3.6.1.4.1.2021.10.1.5.1:
-# DATA:load:data:load5:1.3.6.1.4.1.2021.10.1.5.2:
-# DATA:load:data:load15:1.3.6.1.4.1.2021.10.1.5.3:
+# DATA:load:out:data:load1:1.3.6.1.4.1.2021.10.1.5.1:
+# DATA:load:out:data:load5:1.3.6.1.4.1.2021.10.1.5.2:
+# DATA:load:out:data:load15:1.3.6.1.4.1.2021.10.1.5.3:
 #
 # DATA:mem:label:Memory status
-# DATA:mem:data:memTotalSwap:1.3.6.1.4.1.2021.4.3.0:
-# DATA:mem:data:memAvailSwap:1.3.6.1.4.1.2021.4.4.0:
-# DATA:mem:data:memTotalReal:1.3.6.1.4.1.2021.4.5.0:
-# DATA:mem:data:memAvailReal:1.3.6.1.4.1.2021.4.6.0:
-# DATA:mem:data:memTotalFree:1.3.6.1.4.1.2021.4.11.0:
-# DATA:mem:data:memShared:1.3.6.1.4.1.2021.4.13.0:
-# DATA:mem:data:memBuffer:1.3.6.1.4.1.2021.4.14.0:
-# DATA:mem:data:memCached:1.3.6.1.4.1.2021.4.15.0:
+# DATA:mem:out:data:memTotalSwap:1.3.6.1.4.1.2021.4.3.0:
+# DATA:mem:out:data:memAvailSwap:1.3.6.1.4.1.2021.4.4.0:
+# DATA:mem:out:data:memTotalReal:1.3.6.1.4.1.2021.4.5.0:
+# DATA:mem:out:data:memAvailReal:1.3.6.1.4.1.2021.4.6.0:
+# DATA:mem:out:data:memTotalFree:1.3.6.1.4.1.2021.4.11.0:
+# DATA:mem:out:data:memShared:1.3.6.1.4.1.2021.4.13.0:
+# DATA:mem:out:data:memBuffer:1.3.6.1.4.1.2021.4.14.0:
+# DATA:mem:out:data:memCached:1.3.6.1.4.1.2021.4.15.0:
 #
 # DATA:netio:label:Network IO
-# DATA:netio:data:in:1.3.6.1.2.1.4.3.0:
-# DATA:netio:data:out:1.3.6.1.2.1.4.10.0:
-#    
-# DATA:disc:label:Synology Disc usage
-# DATA:disc:data:disc-free:1.3.6.1.4.1.6574.3.1.1.2::1.3.6.1.4.1.6574.3.1.1.4
-# DATA:disc:data:disc-space:1.3.6.1.4.1.6574.3.1.1.2::1.3.6.1.4.1.6574.3.1.1.5
+# DATA:netio:out:data:in:1.3.6.1.2.1.4.3.0:
+# DATA:netio:out:data:out:1.3.6.1.2.1.4.10.0:
+#
+# ---------- SYNOLOGY specific:
+#
+# DATA:synodisc:label:Synology Disc usage
+# DATA:synodisc:out:data:disc-free:1.3.6.1.4.1.6574.3.1.1.2::1.3.6.1.4.1.6574.3.1.1.4
+# DATA:synodisc:out:data:disc-space:1.3.6.1.4.1.6574.3.1.1.2::1.3.6.1.4.1.6574.3.1.1.5
 #
 # DATA:synotemp:label:Synology NAS temperature
-# DATA:synotemp:data:temp:1.3.6.1.4.1.6574.1.2.0:°C
+# DATA:synotemp:out:data:temp:1.3.6.1.4.1.6574.1.2.0:°C
 #
 # DATA:synoio:label:Synology Space IO
-# DATA:synoio:data:syno-io-read:1.3.6.1.4.1.6574.102.1.1.12.1
-# DATA:synoio:data:syno-io-write:1.3.6.1.4.1.6574.102.1.1.13.1
-#    
+# DATA:synoio:out:data:syno-io-read:1.3.6.1.4.1.6574.102.1.1.12.1
+# DATA:synoio:out:data:syno-io-write:1.3.6.1.4.1.6574.102.1.1.13.1
+#
 # ----------------------------------------------------------------------
 # 2020-08-11  <axel.hahn@iml.unibe.ch>            initial version
 # 2020-08-13  <axel.hahn@iml.unibe.ch>            add host in label for counter data
@@ -58,6 +69,7 @@
 # 2022-10-21  v0.5  <andrea.gottsponer@unibe.ch>  remove grep: warning: stray \ before white space
 # 2022-10-25  v0.6  <axel.hahn@unibe.ch>          fix empty value in performance data; shell fixes
 # 2023-05-05  v0.7  <axel.hahn@unibe.ch>          source shared func, support snmpv3; add synoio
+# 2023-05-16  v0.8  <axel.hahn@unibe.ch>          add about for general infos and without perf data
 # ======================================================================
 
 . $(dirname $0)/inc_pluginfunctions
@@ -65,14 +77,10 @@
 
 # --- basic vars
 self_APPNAME=$( basename $0 | tr [:lower:] [:upper:] )
-self_APPVERSION=0.7
+self_APPVERSION=0.8
 
 METHOD=""
 
-# --- OID declarations
-# OID_syno="1.3.6.1.4.1.6574"
-# OID_ucdavis="1.3.6.1.4.1.2021" # University of California, Davis - private UCD SNMP MIB extensions
-
 # --- output variables
 SYNO=""
 out=""
@@ -95,13 +103,13 @@ _wd()
 # get line(s) for config
 # param  string  one of label|data
 _cfg_reader(){
-    grep "^# DATA:$METHOD:$1:" $0
+    grep "^# DATA:${METHOD}${1}" $0
 }
 _cfg_getlabel(){
-    _cfg_reader "label" | cut -f 4- -d ":"
+    _cfg_reader ":label:" | cut -f 4- -d ":"
 }
 _cfg_dataitem(){
-    _cfg_reader "data" | cut -f $1 -d ":" | while read item
+    _cfg_reader ":out:" | cut -f $1 -d ":" | while read item
     do
         echo -n "$item "
     done
@@ -150,7 +158,7 @@ function showHelp(){
     local _methods=$(
         _cfg_getMethods | while read -r line
         do
-            METHOD=$(echo "$line" | cut -f 1 -d ":")
+            METHOD=$(echo "$line" | cut -f 2 -d ":")
             descr=$(_cfg_getlabel)
             printf "                          %-10s %-50s\n" "$METHOD" "$descr"
         done        
@@ -247,10 +255,10 @@ if [ -z "$info" ]; then
     showHelp
 fi
 
-prflist=( $(_cfg_dataitem 4) )
-oidlist=( $(_cfg_dataitem 5) )
-unitlist=( $(_cfg_dataitem 6) )
-looplist=( $(_cfg_dataitem 7) )
+prflist=( $(_cfg_dataitem 5) )
+oidlist=( $(_cfg_dataitem 6) )
+unitlist=( $(_cfg_dataitem 7) )
+looplist=( $(_cfg_dataitem 8) )
 
 # --- check for looplist
 if [ -n "$looplist" ]; then
@@ -291,25 +299,38 @@ do
     value=$(_get ${oidlist[$index]})
     unit="${unitlist[$index]}"
 
-    # handle loop data
-    if [ -n "$looplist" ]; then
-      _wd "$( printf '%-14s %s %s' $label $value $unit )"
-    else
-      # handle counter data
-      if [ "$(_iscounter ${oidlist[$index]})" = "true" ]; then
-          value2=$(ph.perfdeltaspeed "snmp-data-${SNMPTARGET}-${method}-${label}" $value)
-          _wd "$( printf '%-14s total: %-14s delta: %6s %s per sec' $label $value $value2 $unit )"
-          value=$value2
-      elif [ "$(_isinteger ${oidlist[$index]})" = "true" ]; then
-          _wd "$( printf '%-14s %s %s' $label $value $unit )"
-          value2=$( echo "${value}" | sed -E "s#([0-9]*) (.).*#\1\2#g")
-          value=${value2}
-      else
-          _wd "$( printf '%-14s %s %s' $label $value $unit )"
-      fi
-    fi
+    isperf=1
+
+    outtype='text'
+    test "$(_iscounter ${oidlist[$index]})" = 'true' && outtype='counter'
+    test "$(_isinteger ${oidlist[$index]})" = 'true' && outtype='integer'
+    test -n "$looplist" && outtype='looplist'
+
+    # _wd ""; _wd "outtype = $outtype:"
+    case $outtype in
+        counter) 
+            value2=$(ph.perfdeltaspeed "snmp-data-${SNMPTARGET}-${method}-${label}" $value)
+            _wd "$( printf '%-14s total: %-14s delta: %6s %s per sec' $label $value $value2 $unit )"
+            value=$value2
+            ;;
+        integer)
+            _wd "$( printf '%-14s %s %s' $label $value $unit )"
+            value2=$( echo "${value}" | sed -E "s#([0-9]*) (.).*#\1\2#g")
+            value=${value2}
+            ;;
+        looplist) 
+            _wd "$( printf '%-14s %s %s' $label "$value" $unit )"
+            ;;
+        text) 
+            _wd "$( printf '%-14s %s %s' $label "$value" $unit )"
+            isperf=0
+            ;;
+        *)
+            echo "TODO: handle output of type $outtype"
+            ;;
+    esac
 
-    ph.perfadd "${label}" "${value}"
+    test $isperf -eq 1 && ph.perfadd "${label}" "${value}"
 done
 
 
diff --git a/docs/20_Checks/check_snmp_data.md b/docs/20_Checks/check_snmp_data.md
index 27bbc2e9d7df99f237aa94fc88762d372583efa2..ff88cf2998455996a30d82b0ddbcaa6875ec9ce4 100644
--- a/docs/20_Checks/check_snmp_data.md
+++ b/docs/20_Checks/check_snmp_data.md
@@ -14,7 +14,7 @@ Start the script without parameter to get the help.
 ______________________________________________________________________
 
 CHECK_SNMP_DATA 
-v0.6
+v0.8
 
 (c) Institute for Medical Education - University of Bern
 Licence: GNU GPL 3
@@ -23,22 +23,40 @@ ______________________________________________________________________
 SNMP performance data of Synology storages.
 
 USAGE:
-    ./check_snmp_data -h hostname [-C communitystring] -m method
+    check_snmp_data [options] -h SNMPTARGET
 
 PARAMETERS:
-    -h  hostname       as fqdn or ip address
-    -C  communitystr   optional: community string for snmp; default is public
-    -v                 verbose output
+    -a STRING
+        authentication params for snmpwalk/ snmpget to connect to target; 
+        default: \"-v2c -c public\" (Snmpv2 with community string \"public\")
+    -h SNMPTARGET
+        as fqdn or ip address; default: localhost
+    -f FILE
+        read authentication from config file
+        default: "/etc/icinga2/snmp.cfg"
     -m  method         what to show
                        method is one of ...
+                          about      About... general device infos                     
                           cpu        CPU usage                                         
                           load       System load                                       
-                          netio      Network IO (experimental)                         
+                          mem        Memory status                                     
+                          netio      Network IO                                        
+                          synodisc   Synology Disc usage                               
                           synotemp   Synology NAS temperature                          
-                          disc       Disc usage                                        
+                          synoio     Synology Space IO                                 
+    -v                 verbose output
+
+CONFIG FILE:
+    The config file can be multiline and has the syntax
+    [SNMPTARGET[,target2]]:[auth parameters]
+    The auth parameters set the version and all needed values to connect.
+    Snmp v2 uses a community string.
+    Snmp v3 is highly recommended (you should disable Snmp v2) and needs
+    a user and password.
 
 EXAMPLE:
-    ./check_snmp_data -h 192.168.100.12 -v -m cpu
+    check_snmp_data -h 192.168.100.12 -v -m cpu
+
 
 ```