diff --git a/base.py b/base.py
index c0eb505..fb31d77 100644
--- a/base.py
+++ b/base.py
@@ -41,6 +41,8 @@ class HandlerBase:
 
 
 class Client(HandlerBase):
+    dictionary = {}  # dict (kind, uri) of node
+
     def __init__(self, server, streams, instrument_name, device_name):
         super().__init__()
         self.id = uuid.uuid4().hex[0:15]
@@ -50,7 +52,18 @@ class Client(HandlerBase):
             for uri in streams:
                 urisplit = uri.rsplit('://')
                 kind = urisplit[0] if len(urisplit) == 2 else 'secop'
-                node = server.interactor_classes[kind](uri, self.node_map)
+
+                node = self.dictionary.get((kind, uri))
+
+                if node is None:
+
+                    def change_callback(dictionary=self.dictionary, kind_uri=(kind, uri)):
+                        dictionary.pop(kind_uri, None)
+
+                    node = server.interactor_classes[kind](uri, self.node_map, change_callback)
+
+                    self.dictionary[kind, uri] = node
+
                 self.nodes[uri] = node
         self.server = server
         self.instrument_name = instrument_name
diff --git a/client/jsFiles/SEAWebClientCommunication.js b/client/jsFiles/SEAWebClientCommunication.js
index b807388..9cd9280 100644
--- a/client/jsFiles/SEAWebClientCommunication.js
+++ b/client/jsFiles/SEAWebClientCommunication.js
@@ -313,7 +313,7 @@ function reqJSON(s, url, successHandler, errorHandler) {
             : new ActiveXObject('Microsoft.XMLHTTP');
     if (debugCommunication) {
         console.log("%cto server (reqJSON): %s",
-                "color:white;background:darkgreen", url);
+                "background:yellow", url);
     }
     xhr.open('get', url, true);
     xhr.onreadystatechange = function() {
diff --git a/secop-webserver b/secop-webserver
index 35748e2..75d6476 100755
--- a/secop-webserver
+++ b/secop-webserver
@@ -1,9 +1,9 @@
 #!/usr/bin/env python
 
 import sys
-from os.path import expanduser
-#  look for sehistory and frappy at usual locations in home directory 
-sys.path.extend([expanduser('~'), expanduser('~/frappy')])
+#  look for sehistory and frappy
+sys.path.extend(['/sq_sw/linse', '/sq_sw/linse/frappy'])
+
 import argparse
 from webserver import server
 from base import Client
diff --git a/secop.py b/secop.py
index c14ac09..0614aaf 100644
--- a/secop.py
+++ b/secop.py
@@ -49,18 +49,23 @@ class SecopInteractor(SecopClient):
     hide_par = ["baseclass", "class", "pollinterval"]
     skip_par = ["status2"]
 
-    def __init__(self, uri, node_map):
+    def __init__(self, uri, node_map, change_callback=None):
         super().__init__(uri)
         self.module_updates = set()
         self.param_updates = set()
         self.updates = {}
+        self.change_callback = change_callback
         try:
             self.connect()
             node_map.update({k: self for k in self.modules})
-            self.register_callback(None, updateItem=self.updateItem)
+            self.register_callback(None, updateItem=self.updateItem, descriptiveDataChange=self.descChanged)
         except Exception as e:
             print(repr(e))
 
+    def descChanged(self, module, desc):
+        if module is None and self.change_callback:
+            self.change_callback()
+
     def add_main_components(self, components):
         for name, desc in self.modules.items():
             parameters = desc['parameters']