Outdoor beams

[Neil a]

Ok so installed outdoor beams connected to an old alarm with bell on outside,all working but had two alarms already birds etc
It’s connected to a optima plus two
I also have an old galaxy g2-20
Am I correct in reading somewhere that this as a double knock which allows the zone to be triggered but won’t set alarm off unless is set off twice (within the time frame ) thanks

 

[scott1980]

Double knock is a feature of some control panels, the G2 doesn't have this option and I'm fairly sure that the Optima doesn't either (you'd have to check the manual). The problem with double knock in this situation is that someone would have to walk through the beam twice within a predetermined period to activate the alarm, which may or may not happen.

Most decent beam sets will have an obscuration delay control that can be adjusted so that a very quick object passing through the beam (ie a bird) does not trigger it yet a person moving through will. It's worth opening the receiver and having a look, certainly the Optex/Takex beams I have used (I have a set in the garden) have this feature

 

[sparkymarka]

What beams are they ? .....make and model

 

[Neil a]

These ones

 

[scott1980]

There's your problem, those are gate safety photocells, designed to be very fast acting across a short distance and probably too sensitive for this application. They're also difficult to line up on anything other than a flat and perpendicular surface. I'd recommend swapping them for something like a Takex PB-30 set. They're more adjustable in terms of alignment and you can tweak the response time as I mentioned above. It's worth the investment if you want reliability!

 

[bernardgreen]

A twin beam system is less likely to false alarm on a bird ( unless it a very large one )

 

[Neil a]

There's your problem, those are gate safety photocells, designed to be very fast acting across a short distance and probably too sensitive for this application. They're also difficult to line up on anything other than a flat and perpendicular surface. I'd recommend swapping them for something like a Takex PB-30 set. They're more adjustable in terms of alignment and you can tweak the response time as I mentioned above. It's worth the investment if you want reliability!

Thanks for info they are about 12metres part and very easy to line up.will take a look at the takex

 

[sparkymarka]

I’ve got a set of SL-350QDP Across my garage ....bit overkill but they only cost me £45 ( £250....RRP ) but not had any false alarms since install ( 12months ago ) and it’s set 20hrs a day ...

 

[Neil a]

I have a texecom house alarm so reading instructions this one has a double knock (the beams are fixed about 2feet from back fence going across the garden )so if anyone came over fence and then went to go back it would trip. My other thing is they are under 3 large trees so my other question is if I change beams would the others be ok in the same situation.

 

[sparkymarka]

Yours has single beam , most security beams will have 2 or 4 beams ....

 

[Neil a]

View attachment 194100 Yours has single beam , most security beams will have 2 or 4 beams ....

So does all 4 need to be crossed to trip alarm

 

[sparkymarka]

Yes or 2 on a twin only model