diff --git a/devapp/dev_types.py b/devapp/dev_types.py
index 73156e5..05d8a5e 100644
--- a/devapp/dev_types.py
+++ b/devapp/dev_types.py
@@ -438,16 +438,16 @@ class ZteOnuDevice(OnuDevice):
             onu_type = self.get_item('.1.3.6.1.4.1.3902.1012.3.28.1.1.1.%s' % fiber_addr)
 
             sn = self.get_item('.1.3.6.1.4.1.3902.1012.3.28.1.1.5.%s' % fiber_addr)
-            # sn = sn.encode()
-            sn = ''.join('%.2X' % ord(x) for x in sn[-4:])
+            if sn is not None:
+                sn = 'ZTEG%s' % ''.join('%.2X' % ord(x) for x in sn[-4:])
 
             return {
                 'status': status,
                 'signal': conv_signal(safe_int(signal)),
-                'distance': int(distance) / 10,
-                'ip_addr': ip_addr if ip_addr else None,
+                'distance': safe_int(distance) / 10,
+                'ip_addr': ip_addr,
                 'vlans': vlans,
-                'serial': "ZTEG%s" % ''.join(sn),
+                'serial': sn,
                 'int_name': int_name,
                 'onu_type': onu_type
             }
diff --git a/devapp/templates/devapp/custom_dev_page/onu_for_zte.html b/devapp/templates/devapp/custom_dev_page/onu_for_zte.html
index c0729a8..f7a0d0f 100644
--- a/devapp/templates/devapp/custom_dev_page/onu_for_zte.html
+++ b/devapp/templates/devapp/custom_dev_page/onu_for_zte.html
@@ -73,7 +73,7 @@
                                 </div>
                                 <div class="media-body">
 
-                                    <b>{% trans 'Distance(m)' %}</b>: {{ onu_details.distance }}<br>
+                                    <b>{% trans 'Distance(m)' %}</b>: {{ onu_details.distance|default:'-' }}<br>
                                     <b>{% trans 'Signal' %}</b>: {{ onu_details.signal }}<br>
                                     {% if onu_details.ip_addr %}
                                         <b>{% trans 'Ip addr' %}</b>: {{ onu_details.ip_addr }}<br>
@@ -81,9 +81,9 @@
                                     {% if onu_details.vlans %}
                                         <b>{% trans 'VLan list' %}</b>: {{ onu_details.vlans }}<br>
                                     {% endif %}
-                                    <b>{% trans 'Serial' %}</b>: {{ onu_details.serial }}<br>
-                                    <b>{% trans 'Onu type' %}</b>: {{ onu_details.onu_type }}<br>
-                                    <b>{% trans 'Name' %}</b>: {{ onu_details.int_name }}
+                                    <b>{% trans 'Serial' %}</b>: {{ onu_details.serial|default:'-' }}<br>
+                                    <b>{% trans 'Onu type' %}</b>: {{ onu_details.onu_type|default:'-' }}<br>
+                                    <b>{% trans 'Name' %}</b>: {{ onu_details.int_name|default:'-' }}
 
                                 </div>
                             </div>