diff --git a/xCAT-server/lib/xcat/monitoring/pcpmon.pm b/xCAT-server/lib/xcat/monitoring/pcpmon.pm
index 3b7731590..0af1be3ed 100644
--- a/xCAT-server/lib/xcat/monitoring/pcpmon.pm
+++ b/xCAT-server/lib/xcat/monitoring/pcpmon.pm
@@ -57,8 +57,11 @@ sub start
     my $value=5; #default
     my %settings=xCAT_monitoring::monitorctrl->getPluginSettings("pcpmon");
     
-    my $reading=$settings{'ping-interval'};
-    if ($reading>0) { $value=$reading;}
+    my $reading;
+    if (exists($settings{'ping-interval'})) {
+      $reading=$settings{'ping-interval'};;
+      if ($reading>0) { $value=$reading;}
+    }
     
     #create the cron job, it will run the command every 5 minutes(default and can be changed).
     my $newentry;
diff --git a/xCAT-server/lib/xcat/monitoring/xcatmon.pm b/xCAT-server/lib/xcat/monitoring/xcatmon.pm
index 60ed67808..9f1f30dfe 100644
--- a/xCAT-server/lib/xcat/monitoring/xcatmon.pm
+++ b/xCAT-server/lib/xcat/monitoring/xcatmon.pm
@@ -131,8 +131,11 @@ sub startNodeStatusMon
   #foreach (keys(%settings)) {
   #  print "key=$_, value=$settings{$_}\n";
   #}
-  my $reading=$settings{'ping-interval'};
-  if ($reading>0) { $value=$reading;}
+  my $reading;
+  if (exists($settings{'ping-interval'})) { 
+    $reading=$settings{'ping-interval'};
+    if ($reading>0) { $value=$reading;}
+  }
    
   #create the cron job, it will run the command every 3 minutes.
   my $newentry;