Pyronix Enforcer Frequency Jamming

[FamilyGuy123]

Hi All,

Very frustrated with my Enforcer at the moment and hoping someone here can help.

The alarm has been working fine since installation 14months ago and then suddenly last 3 days the alarm has gone off whilst we're in the house. Always happens around midday each day.

Error message on control panel states: "Wireless JammWZm"

Rang Pyronix and they said there is another device transmitting on same frequency as Enforcer (868MHz) which is triggering alarm. Advise was that I need to make all other transmitting devices in the house dual frequency since Enforcer cannot be changed.

Surely there must be a better (and cheaper) solution?!

For info, only new device fitted in the house was a Virgin Media Superhub3 last weeked, but that can't be the issue as it uses 5Ghz and 2.4Ghz.

Would appreciate any help.

FG

 

[Alarm Engineer]

This happens when any alarm panel is bombarded with multiple signals on the same frequency at the same time. This could be in your house or a neighbouring property. Some streets now have remote control street lighting which can cause this. (Look for a stubby Ariel on top of street light) A Wireless heating thermostat with a low battery is another example.

Jamming is designed to detect if someone is trying to jam your alarm but can be disabled or delayed longer in “system timers” if you have access to the enginner programming menu. You would do this at your own risk.

 

[FamilyGuy123]

Thanks for the quick reply.

Our street lights have been recently upgraded so will check for ariel when I get back home. We have a thermostat but it's not wirelessly controlled so don't think that is jamming.

I do have access to the engineering programme menu. Will have a look at system timers, but is there a way to reduce the volume or silence alarm when jam detected? Currently the alarm is really loud and worried that this might happen in middle of night and disturb neighbours.

FG

 

[Alarm Engineer]

Sounds like it could be your streetlights, we’ve had loads of customers with new streetlights and now having jamming problems.

System timers, Jamming Time (Adjust at your own risk)

Volume control, Day alarm (I always put this on level 2 along with tamper. This only affect internal noises when unset).

 

[Alarm Engineer]

Sounds like it could be your streetlights, we’ve had loads of customers with new streetlights and now having jamming problems.

System timers, Jamming Time (Adjust at your own risk)

Volume control, Day alarm (I always put this on level 2 along with tamper. This will only affect internal noises when unset).

- This does not affect the external siren.

 

[FamilyGuy123]

Sounds like it could be your streetlights, we’ve had loads of customers with new streetlights and now having jamming problems.

System timers, Jamming Time (Adjust at your own risk)

Volume control, Day alarm (I always put this on level 2 along with tamper. This only affect internal noises when unset).

Thanks for that. We're going to have to rule out street lights. No ariel on top. I've also rang the council and all they did was convert the lights to LED.

Had a chat with my neighbour and he has not installed any transmitting devices recently.

I've checked the Jamming Time and it is already on 100secs, which I believe is the max it can be?

Day alarm is now set to level 2. I've not changed any other setting.

One other thing, I checked the panel logs and when I press 'C' for more details on Wireless Jamming entry it states WZm-00. Which device could that be as my inputs are labelled 1-6 and bell currently deleted (awaiting battery replacement).

FG

 

[Alarm Engineer]

Wzm-00 is the onboard wireless receiver/transmitter responsible for all wireless devices.

Set the Jamming timer to 000 to disable if you want.

 

[FamilyGuy123]

Update:

Alarm was fine all weekend and then went off again today This time it happened around 7.30am with the same error message.

I'm tempted to disable Jamming Time but worried this will leave me open to a genuine attempt to jam the signal.

Could there be a fault with the onboard wireless receiver/transmitter?

FG

 

[Alarm Engineer]

Could there be a fault with the onboard wireless receiver/transmitter?

Unlikely.

 

[FamilyGuy123]

Hmmm.....is there any other way of finding out what could be causing the jamming?

 

[bernardgreen]

Hmmm.....is there any other way of finding out what could be causing the jamming?

Using an off air receiver to analyse the interfering signal might indentify the type of equipment that is interfereing with your alarm. Then using a directional antenna (aerial) it might be possible to locate the source.

If the source of the interference is equipment that complies with the regulations for Licence Exempt equipment there is nothing you can do about it.

 

[Alarm Engineer]

The most likely cause is as mentioned before is a third party Wireless device on the same radio frequency (868mhz) transmitting a low battery message or similar. This could be from a neighbouring property’s wireless thermostat, streetlight, Door bell or another wireless alarm.

 

[FamilyGuy123]

Thanks for both your replies. I have been away due to work and the alarm only went off once (on Wednesday). I will look into the off air receiver.

I had a thought whilst I was away....could it be the bell box causing the jam?

In early November, the alarm would go off because it could not communicate with the bell due to low battery. I am awaiting a new battery and have deleted the bell from devices list in the meantime.

Could the bell still be sending out a low battery signal on same frequency?

FG

 

[FamilyGuy123]

Looks like I was wrong about the remote street lighting. Just had this response from the suppliers forwarded to me by the Council.

The Telensa Remote Street Lighting System operates in an unlicensed frequency band 868MHz, which have been tested to comply with British and International best practice guidelines and European Radio Regulations mentioned in EN300-220. All equipment is CE approved.

The DownLink (DL) is within 869.4 – 869.65 MHz and UpLink (UL) is in 868 to 868.6 MHz; your network is deployed in a number of cells with UL channels chosen in the bottom, middle or top third of the UL range. Modulation is BFSK, with lower bit rates and bandwidths than typical household alarms (DL: 500bps, 25kHz channel; UL: 62.5bps, 15kHz channel... the centre frequency of a transmission may occur at different locations within the channel). Max Telecell ERP is 25mW.

With regards to triggering 'jamming' thresholds our Telecell transmissions do not exploit the possibility of such a long transmission to trigger a jamming signal (typically 30 seconds in a 60 second period, although I am unsure exactly how the jamming detection works). As street lights do not need to transmit large amounts of data we are able to use a radio system called UNB, (Ultra narrow band radio), which inherently has a very low data rate due to the narrow bandwidth of the signal. This technique enables us to receive down to very low levels. e.g. -135dBm. Although this equipment is inherently low-power its UNB radio allows data to be communicated 2-3Km in Urban areas and 4-7Km in rural areas [distances achieved depends upon many factors including local interferes and the topology of the area between transmitter and receiver]. Good Line Of Site links have been established over 10Km.

The absolutely longest transmission (which includes a number of 16ms gaps) from a single TC is 6.4s, which can only happen once in a 24s frame.

Retries / re-transmissions may happen in poor conditions, but these are managed within the above constraints, as are any downloads. Acknowledgements can happen, but these are in the 869.4 – 869.65 sub-band.

They also go on to say:

A conversation with the likes of Pyronix is already taking place. It is possible to move the Telensa channels (if close to the alarm frequency) but we are finding that this does not necessary resolve the issue as the alarm could be triggered by a combination of a number of users within the unlicensed band and may be a result of the alarm channel bandwidth being sufficiently wide to pick up all channels. As a result the resident with the issue should contact their alarm supplier.

 

[aptsys]

There are a lot of devices operating in the unlicensed frequency bands. Most of the defined protocols shouldn't cause any issue with an alarm panel as it should have undertaken wireless coexistence testing in order to pass approvals.
I would guess it's more likely to be a home automation or remote control device. Some of the sub-GHz modules I've looked at use custom protocols which can easily hog the band as long as it likes. It'll be in a probably be in a property nearby as the ERP is limited, so wide channel usage will result in shorter range but I doubt you'll be able to do anything about it - this is an issue with the panel.