Yale 6400 signal loss?.

[bernardgreen]

Any equipment that uses radio on a Licence Exempt frequency is going to be at risk of being affected by other equipment using the same frequency.

If the system uses two way communication protocols between panel and sensors then almost all legal interference can be managed without compromising the alarm function. The worst that can happen ( with legal interference ) is that messages may be delayed for a few seconds until the channel become clear enough for the alarm system to pass its message(s)

What is "legal interference" ?

The requirements of the Licence Exempt equipment is that the design must accept interference from other Licence Exempt sources and still function in a way that the user finds acceptable. For this reason no Licence Exempt equipment ( in the frequencies used for alarms ) is permit to transmit for more than 10% of the time. In theory 9 systems using two way communications could "co-habit" on the same frequency without affecting the functions of each other other than delaying messages. System using one way comms would not function well in that situation as the sensors without recievers have no way of knowing [a] that the channel is clear before they transmit and no way of knowing whether the message was received by the panel.

Legal interference has to be accepted and no action will be taken against any equipment operating within the terms of the Licence Exempt regulations.

In some applications the ratio is set at less than 1%

Equipment that does not comply with Licence Exempt regulations may produce interference that is not "legal" and action can be taken against the user of such equipment but finding the source and obtaining evidence in one off domestic situations will be more expensive than installing a wired system to replace the compromised wireless system.

 

[JohnD]

The investigation required to find the cause would need to include at the very least monitoring the radio channel for activity.

Unless, of course, we find that a simple user action like changing the batteries or moving the panel and/or the sensor away from some piece of metalwork or electrical item cures the problem, in which case we can deduce that whatever corrective action cured the problem was related to whatever the cause was. It never hurts to start by trying the easy things.

House holders are told that most non profession and / or DIY systems can cope with interference.

I haven't seen people going round saying that on every Yale thread.

Let's try again shall we?

I have no idea what point you think you are making, and will not try to guess what's inside your head.

 

[bernardgreen]

I wrote

House holders are told that most non profession and / or DIY systems can cope with interference. So they assume false alarms and failures to activate are equipment faults and not the result of interference.

JohnD commented

I haven't seen people going round saying that on every Yale thread.

You will only hear it from sales people who want to make a sale by ignoring the problems that interference will cause.

Unless, of course, we find that a simple user action like changing the batteries or moving the panel and/or the sensor away from some piece of metalwork or electrical item cures the problem

There is no polite way to answer that. It shows how ignorant you are about radio propagation and how it is affected by the environment.

Changing the batteries on a sensor ( unless they are almost totally dead ) will NOT affect any problems caused by interference because the output power from the sensor's transmitter is fixed. To increase the power by altering components in the transmitter would make the item illegal to operate.

Relocating items will alter the propagation paths and may alter the ratio of signal strengths ( sensor relative to interference ) such that the system works but to ensure it continues to work the new environment must be maitained. As you admit one only has to move metal items or electrical equipment to "improve" the situation. But moving your items to improve your system may adversely affect the nearby system that was affecting your system. The owner of that system starts moving things around and that could affect your system.

The bottom line is on Licence Exempt equipment the system must work as required in the presence of interference that is not continuous. The system should work in the gaps between interference if the interference is strong enough to block messages.

 

[JohnD]

I've never met a Yale salesman, so I haven't experienced that.

Unless, of course, we find that a simple user action like changing the batteries or moving the panel and/or the sensor away from some piece of metalwork or electrical item cures the problem

There is no polite way to answer that. It shows how ignorant you are about radio propagation and how it is affected by the environment.

Perhaps you miss my point.

If the user has a problem on his system, and if, for example, the problem goes away when the panel is moved away from steel scaffolding (as in my case) then I would deduce that the problem was caused by the steel scaffolding, which is easily rectified, and not by rf interference. If the problem is removed by fitting new batteries to the sensor, then I would deduce that the problem was due to the old batteries. I do not start from the presumption that RF interference will be the cause of the problem. Is there a logical error in my reasoning? Or have you in some way already determined that in Planebreaker's case, the cause of his particular problem is RF interference?

 

[bernardgreen]

Perhaps you miss my point.

No I haven't

if, for example, the problem goes away when the panel is moved away from steel scaffolding (as in my case) then I would deduce that the problem was caused by the steel scaffolding

The important question to ask is how the scaffolding affected the system.

Did it weaken an already weak signal from the sensor or did it increase the effect of an interfering signal ?

If the sensor's signal at the panel was border line functional, that is just strong enough to be received correctly by the panel then a person standing in the line between sensor and panel could reduce the signal enough to prevent the panel being able to receive it. That person could be an intruder.

It is good practise when installing radio equipment to reduce transmitter powers while testing and then returning them to normal when put into service to allow for signal loss by bodies and other effects.

 

[JohnD]

have you in some way already determined that in Planebreaker's case, the cause of his particular problem is RF interference?

 

[experienced]

have you in some way already determined that in Planebreaker's case, the cause of his particular problem is RF interference?

I think there is an assumption it's inteference but would that not cause jamming and the siren to activate? Maybe it's not inteference but a local shielding of signals.

 

[bernardgreen]

I think there is an assumption it's inteference but would that not cause jamming and the siren to activate? Maybe it's not inteference but a local shielding of signals.

The system appears to have worked quite well for some months and them problems began. The type of problems described as loss of signal could be a defective sensor if it were only one sensor involved. The OP mentions door contact not starting count down and PIRs detecting motion but not being received at the panel so the problem is most likely reception by the panel is poor and not transmitters.

That strongly suggests channel blocking ( interference or intentional jamming ).

The system must accept blocking of the channel by legal interference ( non continuous ) and this should not trigger an alarm, but it should provide a warning of high channel occupancy as an indication that system functions may be compromised. Continuous blocking (which is either intentional jamming or rogue equipment not complying with Licence Exempt restrictions) should produce an urgent warning to indicate the system is compromised. In the case of systems where there is only one way wireless communication to the siren this alarm has to be raised at the siren when it finds its receiver is blocked.

It does surprise me that the system is not provided with a channel monitoring facility. The panel's receiver could control an LED to enable the user to see when there is activity on the channel. If the LED is lit when none of the system's sensors are activating then there is interference.

I would fit two LEDs Red to light if there was any transmissions on the channel and green if the activity was from one of the system's "learnt in" sensors.

 

[experienced]

At last a good conversation about RF and cheaper systems.
The OP mentioning there are \"hundreds\" here. I am surprised they do not all set and unset when one person leaves/enters. The cheaper ones do and is funny to watch when one neighbour complains about false activations when their neighbour has one fitted

The Yale devices the OP mentions would not behave in that way as every sensor and device has a unique id. You are just being silly

 

[experienced]

As for the experienced person, a shielding of a one way system would not cause anything but a non activation of any device. So for instance, no knowledge of a missing detector or warning device, even a door left open.

If the sheilding was constant then the panel would flag up an inoperative device. The control panel reports missing devices as out of order.

 

[bernardgreen]

The Yale devices the OP mentions would not behave in that way as every sensor and device has a unique id. You are just being silly

Most manufacturers agree with each other on which IDs will be used by each system preventing IDs being duplicated. However there are manufacturers who do not conform to this agreement so there will be equipment that transmits IDs that will be in the same range and format as those used by reputable manufacturers.

 

[experienced]

I think there is an assumption it's inteference but would that not cause jamming and the siren to activate? Maybe it's not inteference but a local shielding of signals.

The system appears to have worked quite well for some months and them problems began. The type of problems described as loss of signal could be a defective sensor if it were only one sensor involved.
That strongly suggests channel blocking ( interference or intentional jamming ).

It does surprise me that the system is not provided with a channel monitoring facility. .

There is a reporting facility at the control panel. If signals from the sensors do not reach the panel then at the control panel there will be a report indicating sensors out of order. The orange fault light will light up and the panel will beep every 30 seconds and the lcd display will indicate 'lounge pir out of order' or whichever named sensor is affected.
The fact this does not happen with the OPs system indicates the inteference is firstly sporadic and not constant and also not a jamming or blocking issue from an external signal otherwise the siren would activate.

This indicates it is a local intermittent problem near the panel.

 

[experienced]

The Yale devices the OP mentions would not behave in that way as every sensor and device has a unique id. You are just being silly

Most manufacturers agree with each other on which IDs will be used by each system preventing IDs being duplicated. However there are manufacturers who do not conform to this agreement so there will be equipment that transmits IDs that will be in the same range and format as those used by reputable manufacturers.

All Yale devices use the same range and format however every yale sensor has a 'unique ID' , this means that a yale system will only respond to its own learnt in devices.
A neighbours sensors would never set off your alarm. Yales only stipulation about fitting seperate systems is that the sirens should be more than a metre apart.

 

[bernardgreen]

This indicates it is a local intermittent problem near the panel.

Or a remote "intermittent problem" that creates a local intermittent signal strong enough to block the signals from the sensors.

If that remotely generated "local intermittent problem" happens when the sensor is reporting an intruder then the alarm will not be activated. The sensor will go to sleep and stay asleep while the intruder is moving around and only wake up one minute after he or she has left the room.

With two comms the sensor will keep reporting until it receives confirmation that the report has been received.

 

[bernardgreen]

All Yale devices use the same range and format however every yale sensor has a 'unique ID' , this means that a yale system will only respond to its own learnt in devices.

True for devices manufactured by Yale. But if there are device not manufactured by Yale that happen to transmit their ID in the same format as Yale and has the same identity as one of the learn in Yale devices then the panel will accept it.

The chance is very small, almost zero, but it is NOT impossible.

A neighbours sensors would never set off your alarm.

WRONG if the sensor started transmitting continuously due to fault or a non compliant design then the siren's jamming detection would be triggered and the alarm would sound. ( unless tamper was disabled ). This may be connected with the reason sensors go to sleep after reporting motion detected. If they transmitted continuous reports then sirens in the area would go into tamper ( jamming ) alarm state.