sometimes incorrect status reporting door sensor

[Roland declerck 0]

I installed last week a door sensor and the door status reporting is from time to time incorrect.

It is ok for a couple of cycles and then it get blocked on the open or closed status.

After some time it get back to normal. 

Not sure what the problem is:  bad contact with HC2 software 4.14 (sensor and HC2 are place in opposite corners of my house roughly 15m with 2 walls in between, any way to test connectivity?) , 

installation ? ( according spec max 5 mm which it is close to 5 mm), something wrong with the sensor?

Anybody  advise or suggestion on how to get this set-up reliable.

[Roland declerck 0]

I am more and more convinced that the sensor signal is not reaching the HC2. I have noticed that I have majority of the problems 

when the car is in the garage. Hence I believe the car is working as a shield (sensor is situated near the bottom of the garage door).

 

Any suggestion what to do to improve signal transmission: extra modules; zwave extender (which type for Fibaro HC2).

 

Are there apparatus to measure strength of zwave signal?

 

 

[petergebruers 1,261]

A Z-wave extender is just like any mains operated module, but without any other useful function.

 

Recent Fibaro modules contain a reporting function for signal quality, via menu option. For instance, Motion Sensor.

 

Without knowing how many modules you own and if they are "Plus" devices it is difficult to give good advice. Assuming this is a Fibaro D/W version 2, and you have less than 5-10 mains operated modules, your sensor might indeed be in a "dead spot". Adding a module, that is not blocked by the car, might do the trick, because mesh network really works (it is not a gimmick)...

[Roland declerck 0]

As listed below most my devices are "Plus" devices with little presence in garage 1 where the door sensor is situated.
If i ignore the binairy sensor than closed to the problematic door sensor the closest   module is 10m away with one 

wall/car/heating boiler in between. 

Problem is that i do not really need /can place a module in between.

Not sure what to do.

 

4 SWITCH 2                      FGS 223                         CEILING

1 SWITCH 2                      FGS 223                          LIVING

1 SWITCH 2                      FGS 223                          GARAGE OUTSIDE

1 FLOOD SENSOR           FGFS_101 ZW5             CELLAR

1 SMOKE SENSOR          FGSD_002 ZW5             LIVING

1 DOOR SENSOR             FGDW_002 ZW5           GARAGE INSIDE

1 BINAIRY SENSOR         FGBS_001                     GARAGE INSIDE

1 WALL PLUG                   FGWPE_ 001                  LIVING

1 WALL PLUG                   FGWPE_ 002                  LIVING

1 PIR                                  FGMS_001                      LIVING

1  central                           HC2                                  Bureau

Edited November 16, 2017 by Roland declerck

[petergebruers 1,261]

Thank you. That is very useful information.

 

Unfortunately I still have to speculate a bit but if you do not mind that, here we go!

 

The "backbone" of your network is 6xFGS223 and 1x FGBS and 2x FGWP because they can pass messages. Not too bad, but maybe their not in the most optimal location. Maybe your sensor is still in a dead spot.

 

Here is a somewhat generalised  sketch of why that could happen:

 

Please login or register to see this attachment.

 

• Node C represents your sensor. It tries to send an update to your controller.
• Z-Wave radio waves travel in straight lines.
• The direct connection might pass through walls at a certain angle. This makes the appear much thicker, see grey box. Module A's waves go through the wall at a right angle, so the wall's apparent thickness is its normal thickness.
• I have drawn a red arrow to represent a weak signal. The HC might not hear it. Or the module might be unable to receive the acknowledgement, sent by the HC.
• The second red arrow is a communication attempt via another module. Unfortunately, the large metal object blocks the radio waves, so this fails too.
• Module A and B can communicate directly with your HC, hence the green arrows.
• Because of mesh networking, A, B and C can communicate with each other through the orange arrows.
• Communication from C to HC should work, but with a slight delay, because module B has to buffer and forward the information to the HC. With only one hop, this is barely noticeable.

Can you apply this to your setup? Maybe you can find a spot near the garage that looks better, then test with one of your wall plugs.

 

Because your devices are ZW Plus, the sensor should use "explorer packets" to discover new routes. However, I am not sure the D/W sensor sends an explorer packet after every failed attempt. To avoid issues with that, I would do a neighbor update aka mesh reconfiguration on your sensor. So go to the Z-Wave tab,  reconfigure mesh, select the D/W sensor. Then wake up the sensor. You'll have to put the car outside, otherwise you get a catch-22. Because the sensor is in a dead spot, it cannot hear the "mesh reconfigure" request from the controller  Or move the sensor a bit.

 

I am by no means an RF engineer but when I was young I toyed with FM transmission and I also diagnosed WiFi network issues... But I can tell you this: everything you read about the reception (antennas !)and propagation of radio waves is an over-simplification! So is my sketch... Here's a list of some other phenomena to consider:

• Radio waves can reflect of surfaces. The reflected waves can interfere with the original signal and cause dead spots.
• Antennas have a certain radiation pattern and polarisation. You do not have much control over that...
• Pay attention tot both sides... It is bidirectional communication. Maybe moving your HC fixes your problem
• You might have a source of interference, though I have to say it is not very likely because not many devices use this band. Without tools, it is very difficult to find out if this is the case.

I hope this helps. Please keep us informed....

 

 

 

[Roland declerck 0]

Peter, thanks for this extensive reply.

I have put a couple of days ago, on a temporary basis, a FGS223 in the room next to the garage.

I am monitoring the status of the door sensor since then. 

And untill now correct status is reported even with the car in the garage.  So it looks like the sensor is in a dead spot. 

How to cure for ever in am not quite sure as normally i would not put a zwave module in this adjacent room.

But it is fine to understand the issue and what can be done.

 

[petergebruers 1,261]

I am glad you like my explanation. You can show your appreciation by clicking the "like" icon on that post.