Yale 6400 signal loss?.

[bernardgreen]

[QUOTE="charmin, post: 3412985, member: 230200"Obviously it was chucking out some random interference at 433 ish Mhz[/QUOTE]Almost certainly it was operating on 433.92 MHz which is the frequency allocated to licence exempt equipment.

It would be un-likely that the device would transmit continuously if the batteries were close to end of life. ( but they might ) The requirement of the licence exemption is that no device transmits for more than 10% of the time.

There is a possible reason why the temperature sensor transmitted for along period. Some systems use two way communications where a package of data from a sensor will be repeated until the panel sends an acknowledgement to the sensor. If the sensor cannot hear the panels acknowledgement the repeats may be often enough to disrupt communications in other equipment. If a third system ( not your alarm and not your temperature sensor ) has started operating nearby then transmissions from that third system could prevent the temperature sensor from hearing the acknowledgements from its display resulting it the sensor transmitting far more often that it would normally.

Discovering the exact reason for communication failures in equipment operating on a licence exempt frequency requires off air monitoring to find what systems are operating in the vicinity.

 

[secureiam]

@bernardgreen I have known a few devices exhibit this including a wireless contact, during a period where I tested the unit I was receiving low battery signals for some time before the unit croaked and the system was jammed confirmed by the panel log. I wanted to see what happened, also it was a hybrid system and with the jamming none of the radio devices worked which is what you would expect however the hard wired units were still fully functional.

Replacing the battery on that contact resolved the issue in full and immediately, the jamming appeared to be caused only by that device and a battery of insufficient power to function correctly. As the battery removed didn't cause the jamming its unlikely that the receiver was jamming the system just the powered unit.

Given the age battery performance in wireless items can be a good place to look, if a new battery runs down quickly then the device may have developed a fault or possibly subject to interference as you outline above.

I don't imagine many people have the equipment or knowledge to perform such off air monitoring.

 

[bernardgreen]

Replacing the battery on that contact resolved the issue in full and immediately, the jamming appeared to be caused only by that device and a battery of insufficient power to function correctly.

That suggests a bad design, one that is not compliant with the conditions set for operation on a licence exempt frequency.

I don't imagine many people have the equipment or knowledge to perform such off air monitoring.

True, most end users will not have either and neither do most of the people who sell equipment to the general public. So when a system fails due to compromised communications unless the owner / user has access to monitoring equipment the cause is probably not going to be found. And even if it is found it may be a compliant system in which case nothing can be done to close it down.

 

[secureiam]

interesting I suspect when it was approved it wasn't tested to that failure point, as I could monitor the system and had low battery reporting for a month prior and regularly until it failed if it had been replaced straight away (within the warning period) would never have seen the jamming fault.

I was more interested in seeing what happened if I let it run its natural course but a month should be plenty of time to arrange a battery swap (battery was over 2 years old), would have been replaced under a service agreement before the low battery even raised its head. It is always nice to know how a piece of kit performs long term, but things change so fast so chances are the firmware of all the components has been long since upgraded by now so could perform better or different now.

I often wonder how things are certified and tested and wonder if the approvals are actually worth anything.

 

[bernardgreen]

I often wonder how things are certified and tested and wonder if the approvals are actually worth anything.

Some "approvals" are not worth it. With a lot of equipment using licence exempt frequencies it is the manufacturer who self certifies that equipment complies with the requirments. In the past most manufacturers were reputable and their design and production quality controls did ensure compliance. Now there seem to be some reputable companies who have put their trust in sub-contract low cost manufacturer who have altered the design ( cost cutting ) and the reputable company may not be aware that their product is ( no longer ) compliant.

Only when an end user reports problems can something be done. Often though in practise there is nothing that can be done as one condition of using a licence exempt frequency is that the equipment should be able to operate to a satisfactory level in the presence of other users of the same radio frequency.

I would consider equipment that "squarked" when the battery was too low to maintain proper operation of the logic / processing section was a bad design.

 

[secureiam]

I am aware that companies self certify initially and then some get a third part to verify, just to make them look justified. Think sometimes its just a paperwork exercise.

Lets face it how many people are going to run the battery way beyond the warnings that its running low to the point where it fails to process correctly as in the case I outlined and it was complying until it passed over the edge and started causing issues.


I suspect it would make everything very expensive to test comprehensively.

 

[Europlex]

New batteries can be "faulty", it's not a strange occurrence.