Keep dropping Visonic XHS2-TY MCT-350 SMA ZigBee Door Window Sensor

Your still overlapping between the wifi (green area is wifi ch 6) and zigbee. Ideally you don't want any overlap.

Regarding the distance between hub and sensor; that's not really a good measure as AC powered wifi transmits at a much high power level and can drown out a coin cell powered zigbee sensor. The 2.4ghz frequency band is also shared by cordless phones, your microwave oven, bluetooth and the endless variety of wireless devices, keyboards, mice, baby monitors, smart utility meters etc.

Moving your wifi and zigbee networks to other channels won't cause any issues as devices will follow, it's worth a try. And ideally your wifi router should be several feet away from the hub.

You say that your Zigbee devices are 20 ft from your hub. Normally that would be great. However, unless they devices are line-of-sight with nothing intervening, that might not be adequate. For example, I have an outdoor motion detector that is 20 ft from my hub, but there is a brick chimney between it and the hub, so I need a repeater to bypass the chimney obstruction. The repeater is further away from the hub than the sensor is, but the repeater is line of sight to both the hub and the device.

Normally standard gypsum wallboard over wooden studs is not a problem, but if the walls contain HVAC ducts, water piping, etc. that can be an issue. Metal studs used in some newer construction might be an issue. I have an HVAC return duct between my hub and front door lock, so I need a repeater to get around the obstruction. Also things like flat panel TVs, mirrors, aquariums and large appliances can block signals.

Adding Zigbee repeaters to your mesh is not expensive. Many people use the Tradfri repeaters from Ikea. I have had success with the Zigbee 3.0 smart plugs using eWeLink technology. Mine were produced by LUNTAK, but there are several others featuring similar design. Some others on the forum are using these same plugs successfully as repeaters. The nice thing about both the Tradfri and eWeLink devices is that they also repeat for Xiaomi/Aqara devices which many repeaters won't do.

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I changed my WIFI to channel 1 and changed the zigbee channel to 25.
This seemed to help.
I can now see that >Devices>LastActivity has updated to a recent time for the contact sensors.
I can also actively open and close the contact sensors and see HE recognize this.

What I don't understand is why the furthest most room, with poor line of sight, where I had originally paired the contact sensors and reliably reflected open and close status simply stopped working over night?
Now I can walk the working contact sensors a few feet right in front of the Sonoff Outlet (bookshelf) and I cease to be able get live updates from opening/closing contact sensors.
Is the Sonoff outlet an unreliable repeater? It's the S31LIte Zigbee version and can reliably turn switch on and off.
Is there another way to get live feedback about quality of connection? The Child/Route seems to kind of not really try to do this.

"Parent child parameters
EzspGetParentChildParametersResponse [childCount=1, parentEui64=0000000000000000, parentNodeId=65535]

Child Data
child:[snzb4, BC7B, type:EMBER_SLEEPY_END_DEVICE]

Neighbor Table Entry
[Outlet_1-Bookshelf, 3105], LQI:254, age:4, inCost:1, outCost:1

Route Table Entry
status:Active, age:64, routeRecordState:0, concentratorType:None, [Contact_2, 9F32] via [Outlet_1-Bookshelf, 3105]
status:Active, age:64, routeRecordState:0, concentratorType:None, [Contact_1, D400] via [Outlet_1-Bookshelf, 3105]
status:Active, age:64, routeRecordState:0, concentratorType:None, [Outlet_1-Bookshelf, 3105] via [Outlet_1-Bookshelf, 3105]

Seems to indicate the contact sensors are routing thru the outlet repeater?

I should have SNZB1/2/3/4 for the sonoff temp sensors, contact1/2 for 2 visonic contacts, and 1 bookshelf for sonoff outlet.
I don't see any mention of the SNZB sensors.

Is there a primer for the child/route output available? Weird that the bookshelf self references and that most of the temp sensors aren't displayed, that the age is so old, etc.

Thanks for the help

Now my contact sensors have dramatically increased range. IE I can now walk way beyond my bookshelf outlet and the open/close state is registered on HE.

IS there a smarter way to get live feedback? IE open/close won't work with basic temp sensors.

Refreshing child and route gave identical results except for age4 for neighbor...

The only thing I can think of is that the Zigbee channel change to 25 took awhile to update ?

Yes it can definitely take a while for the mesh to settle back down after a channel change.

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Regarding your "missing" sensors. From info I gathered, the hub routing is a snapshot in time of the current routes and devices. Perhaps for a certain period of time like the last 15 minutes.

Also zigbee does not maintain active, constant communications channels. Sensors wake up and communicate when they have something to report then they go back to sleep. So routers and coordinators (hubs) may see sleepy end devices (battery powered) sensors drop off.

And routes devices take aren't always logical in terms of distance or line of sight. I've had sensors in my detached garage use routers that were further away then the hub itself.

Don't get too hung up on the routing. If a device pairs and does what it supposed to do reliably, that's all that matters.

You could look into The Device Watchdog app, It monitors device activity and battery levels and produces a report if a device fails to report after a period of time that you designate.

Here's mine on a dashboard, With several obvious test sensors.


Not to your problem but I found the MCT-350 sensor was stable on my network (with a repeater nearby) but the battery life was horrible. I replaced it with an Aqara sensor.

Thank you all for your thoughtful replies.

I guess I came into this expecting the process to be a little more deterministic given that HE is a COTS product.
Even the official guide is suggesting how days are required for the mesh to 'settle'. This implies a lot more magic (stuff out of my control) than I'd like.

This seems to be supported by the fact that I can have high accuracy, low latency, high responsiveness feedback from a contact sensor during install one evening- i purposely chose a location bridged by a repeater, furthest location and highest physical barriers in the house. Zero responsivity from the same location the next day.
I can re pair in a much more benign location , much closer with LOS and stuff works. Next day feedback is intermittent.

I've since installed the watchdog APP and it provides some useful info.
I think that the child/route output is the most useful in troubleshooting variables that impact comms.. this would have been infinitely more useful if ALL devices regardless of how stale the data was retained in this log..

Right now I'm stuck with brute force feedback (contact sensor open/close).

Luckily the mains installed Sonoff31 Lite zigbee outlet is the only robust item on my network that consistently responds.
Maybe I just need to buy a slew of repeaters and scatter them around the house? I'm not convinced this is the solution since I can spend hours with reliable contact sensor feedback. If this were a mesh connectivity issue, I'd expect that symptoms would be that I have intermittent connection over the course of days rather than the small windows of great responsivity.

Folks have mentioned the IKEA repeater. Just looking at $$ the Sonoff31Lite is only $10 @qty4. Any reason I wouldn't have this be my backbone given the value?

So far the stock batteries on the visonics are reading 100; Will keep an eye on it. IT seemed like a great solution given cost and included temp sensor. I like that they paired with no drama.
Too bad they don't seem to stay connected for unknown reasons.


This may not apply to you but folks have complained that Smart Water meters (from the water company, not an HA product) have caused issues with other wireless devices in the home. Just a thought.

Just a comment on this scenario-- when you take a child 'sleepy end device' out of range of its parent, it's a disruptive change... meaning that the device isn't capable of forwarding its messages immediately through another in-range repeater when it loses contact with its original parent.

First it must recognize that it has been orphaned (a Zigbee child device relies on dedicated send/receive buffers that have been allocated by its parent to store/retrieve its messages)-- this involves scanning all available Zigbee channels to account for a possible network channel change. It then must go through a process of finding a new parent router and rejoining the network.

When it works as intended (not all Zigbee stacks seem to be equally good at doing this) it may only take several seconds, but until the rejoin happens you'll notice the device fail to respond properly until the child/new parent link gets established. Ultimately the device should begin to work again with a new parent without manual intervention (at least when things are working as intended).

It's likely your network would benefit from a few more repeaters, though the one you have does seem to show a good link to the hub. The 'free air' range you may see quoted for Zigbee is reduced to a fraction of that indoors (Control4 recommends no more than 15'-30' between repeaters, and sometimes as little as 6'-9' due to attenuation/reflections of building materials and furniture).

I understand your comments regarding 'real life' range LOS perfect conditions vs various obstacles that attenuate signal to various amounts, interference from WIFI, etc.
I also hear you regarding how slow the mesh repair/redirecting traffic may be. How long would you expect the zigbee mesh to heal after it breaks?

I try to mitigate these unknown variables simply by picking a static worst case scenario, successfully pairing and demonstrating a robust feedback loop (open/close contact) of more than one sensor. I can open and close over a chunk of time (~3 hours in this case) with 100% hit rate on HE status recognition. I can now try the same the next day, same spot, no moving setup and breaking zigbee routings, and not have connection or status is stuck open, etc.

I definitely don't have a complex, dynamic operating environment. As stated above, if I were limited by spotty connectivity, I imagine the first night of testing would yield intermittent results as would the second night. I'd get consistently intermittent results if you will. Right now I'm seeing bursts of clarity which I don't understand.

unless I'm mistaken, I don't have the tools to truly trouble shoot this opaque system.

And I'm relegated to blindly dumping more repeaters on the issue... anyone have thoughts on Sonoff s31Lite outlet repeaters?

Updated :
Parent child parameters
EzspGetParentChildParametersResponse [childCount=0, parentEui64=0000000000000000, parentNodeId=65535]

Child Data

Neighbor Table Entry
[Outlet_1-Bookshelf, 3105], LQI:255, age:3, inCost:1, outCost:1

Route Table Entry
status:Active, age:64, routeRecordState:0, concentratorType:None, [Snzb2, 844E] via [Outlet_1-Bookshelf, 3105]
status:In Discovery, age:0, routeRecordState:2, concentratorType:High Ram, [null, 0000] via [Outlet_1-Bookshelf, 3105]
status:Active, age:64, routeRecordState:0, concentratorType:None, [Outlet_1-Bookshelf, 3105] via [Outlet_1-Bookshelf, 3105]
status:In Discovery, age:0, routeRecordState:0, concentratorType:None, [Contact_2_Garage1Door, 9F32] via [Outlet_1-Bookshelf, 3105]
status:Active, age:64, routeRecordState:0, concentratorType:None, [Contact_3, 1DF9] via [Outlet_1-Bookshelf, 3105]

It's hard to generalize but a small change can be pretty quick. I've experimented, watching a Zigbee sniffer trace (CC2530 and the free TI software). While watching packets from a Kwikset Zigbee lock (checking in every 3 seconds with its Iris V2 plug parent) I'd unplug the Iris and by the time I got back to view the trace, the Kwikset had already aquired a new parent (it had lots of repeaters in range to choose from). It probably happened within 20 seconds.

I mentioned it because if you're testing with a sensor while moving it around, you would notice a disruption during the process as the device gets orphaned until the point that it negotiates with the new parent and rejoined-- messages from the sensor won't be relayed by any repeater that happens to be in range, just the bonafide current parent of the device.

Troubleshooting issues like these can be tricky without visibility into what's going on. I was helping a friend troubleshoot his SmartThings Zigbee network last week-- it handled his collection of Cree bulbs, outlets and motion sensors flawlessly for years with the exception of cloud issues. But suddenly things stopped working well; timed lighting events became flaky and devices weren't responding to the app.

Ultimately it turned out that his wifi router was located very close to his ST hub-- within a couple of feet. This is bad; regardless of what wifi channel you are using, the sidelobe interference (within roughly 3 feet or so of the router) can swamp the Zigbee radio. It always had been located there and had apparently never caused any issues-- Zigbee can be pretty resilient and his stuff had been working.

Recently (coinciding with the start of the problems) he had rearranged the antenna orientations on the router trying to optimize wifi range. This was enough to tip things over the edge and caused his Zigbee issues-- when he had all four of the router's antennas pointed straight up, Zigbee worked. Moving them in different angles (better for wifi coverage) effectively swamped his nearby ST hub. Relocating it a few feet farther away solved his problems.

You don't have to go hog wild with repeaters but having two or three even in a small setup is reasonable.

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Ironic... I had 2 of my Vision MT-340's drop off the mesh in my shed this week. I have never had any issues before with them. I had to re-pair them to get them to work again. I was using channel 20. I thought that maybe a neighbor was causing interference so I relocated them to channel 25 but they wouldn't work. I dropped back to 20 and keeping my fingers crossed. Weird coincidence that you are having issues all of a sudden as well.

I'd actually say I never got off the ground.
Only my sonoff zigbee outlets and ecobee are reliable. Sonoff Temps and Visonic Contacts are a crap shoot.

I have 13 other Visionic MT-340s that work flawlessly. The ones in my shed are the only ones that seem to have failed. I can only assume that there is some interference on that Zigbee channel on that hub. Unfortunately I have run out of unique Zigbee channels because of the number of zigbee networks that I have, so moving the channel is a problem.

That brings up an interesting question. Do ZigBee radios do any self arbitrating traffic management like 802.11 WiFi "attempts"; to yield way/take way (as I understand it) or do they just brut force things, collide, and "drop packets" ?

Zigbee can use a couple of 802.15.4 mechanisms for channel access; in 'beacon mode' the coordinator sets up predetermined intervals (which can include guaranteed timeslots for QOS) during which the devices waken and communicate. They still use CSMA-CA (collision sensing) to contend for the timeslot if they need to transmit. Supposedly beacon enabled mode enables more efficient use of radios and even enables the use of battery-operated coordinators; timeslots can be set anywhere from 15ms to 252 seconds apart.

Sensor based networks (like Zigbee Home Automation) run in non-beacon mode; sensors sleep almost all the time but can have non-coordinated wakeup intervals to announce their presence.

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You should be able to run multiple zigbee networks on the same channel.

I run 3 zigbee networks all on ch 25 without issue, HE, Zigbee2MQTT and a DIY tasmota based hue bridge.

Are you basing all your observations on this single contact sensor? Perhaps its a bad sensor.

Perhaps it just doesn't play well with the sonoff plug. The chinese have been proven to not follow ZHA (Xiaomi) accurately. ​Even though your sensor may not route through it, there could still be some issue. Without a sniffer your simply left with trial and error.

I use the MCT-340 and the are rock solid and respond virtually instantaneously. Along with my Bosch, Iris (V2&V3) & Sonoff, Heiman and a few generics.

Zigbee and Hubitat are not your issue here. Something else is going on.

Not all sensors, even from same mfg are the same. Even the same model can vary during production due to firmware changes, hardware variances, etc. And given that zigbee firmware updates are virtually non-existent, software on most if not all sensors doesn't get fixed or improved.

The model number you give for the sensor you have would suggest that it is for/from Xfinity. That could suggest some variance in the firmware to tailor it to Xfinity. Just a thought.

If this question reference to me:
I'm basing my feedback on qty5 visonic xfinity contact sensors, 4 sonoff temp sensors, and 2 sonoff s31 lite zigbee outlets. All devices are zigbee.

WIFI is on channel 1 and Zigbee on 25

Outlets are rock solid no problems. They are constantly tethered to Hub and I can turn on turn off with minimal lag, comm issues. (not sure why LQI on basement is high but in/out costs are high)
Neighbor Table Entry
[Outlet_2_BasementStairs, 1020], LQI:251, age:4, inCost:3, outCost:7
[Outlet_1-Bookshelf, 3105], LQI:254, age:4, inCost:1, outCost:7

Temp sensors and contacts decided to fall off network a week ago and never hopped back on. They pair with minimal issues. I've rebooted HUB several times. THere are small windows where everything will work great. Most of my feedback is with contact sensors since there's a tangible feedback mechanism. It doesn't seem like a mesh signal issue since it works great and then it doesn't. But also doesn't seem like a HUB issue since ecobee, outlets work great.

It doesn't seem like a sensor issue.. despite them pairing with different properties (IE only some contacts have temp or some temp sensors have humidity).

Regarding your thoughts on firmware, I guess this doesn't ring true to me since I can initially pair beautifully and I can open and close for the evening to my hearts content and see all changes reflected. Yet subsequent day it just ghosts me.

I'm at a loss. I don't see any reason for this stuff to converge since anything else I'd do would basically be the same thing I've already done.. so I'm really dragging my feet on this =(.

I do appreciate everyone's feedback, though