Using An Indoor Visonic Discovery Pir Externally

[vivtal]

Hi Viv,

not tried working with PIRs in very hot climates, you would be better going for 'dual tec' unit, these have PIR and Micro wave detectors cross each other so as to eliminate activations from problem sources (with differ for each technology).

some domestic pir's cn be slow t detect if both the background and the subject are at warm temperatures, often a person who has been in a house for some time may not trip a pir immediately when passing by, but then a person walks in who has just come from say the garden, it works straight away.

as your fairly restricted for kit and so choice where you live, i would suggest perhaps source from Ebay if you have access, obviously you need to find vendors happy to post to India, we have many of you nationals over here running businesses, so a bit of research to be done (or invite one of us lot over for a free holiday in your beautiful country ).

we have more sophisticated alarm systems available which can be interfaced with to control lights even operate access control, but you seem to be going for a more sophisticated home automation plan.

to be quite frank (but i hope not condescending) we get many such enquirers on this forum, it usually leads to a lot of wasted time, money and many many tears. my very best advise is to keep it really simple in order to keep it really effective.

this forum has 7000+ members yet with all that undoubted excellent ability available i'd be surprised if even 5 of them have full home automation - sort of tells it's own story don't you think?

regs

alan

Hi Alan and Everybody,

Thank you very much, I guess, I will have to wait till I get my hands on the external PIRs as advised.

I also have Dual Tec PIR (Intellisense) and it's used indoors (with my DSC), so I guess if I cannot get the external PIRs then probably I have to ask the Alarm company to disconnect this (dual tec) and use the visonic indoors.

The reason I was planning to use a PLC because basically I am an embedded systems designer and little conversant with PLCs in general. Acc. to me (and I may stand corrected most of the security panels/home automation are (probably) little variations on the basic PLC concept/theme. Also since PLC's were there earlier, their construction is quite robust even for an entry level PLC, whereas I am not sure whether a low to mid-end security system can boast that level of robustness. (This is just my opinion and I do not have any data to support it)

Finally, the cost. A typical 20 point PLC retails about 150 GBP in India whereas I paid almost double for the DSC (Power632, which I think is the entry-level). Funnily enough, the Optex external PIR LX-402/802 retails at about 70 GBP per piece in India. whereas I picked the visonic/ Dual Tec Intellisense PIR for 8 GBP (per piece) about 1- 1/2 years ago in ebay.uk (when I was visiting at that time)

Anyway, thanks again, and I will keep you posted if I go-ahead and try atleast once. I now have about 9 of these PIRs and won't mind much sacrificing one just to satisfy my curiosity And as I have said earlier, I just require detection in the night whereas in the day I would be programming the PLC to ignore.

Regards,

Viv

[vivtal]

I forgot to mention how I plan to use the PIR externally.

In my small garden which is about 12 feet by 15 feet wide and recessed in the building (C shaped), I have a mild-steel pergola at a height of 16 feet. On top of this pergola, I have a 6mm double wall and sloped polycarbonate sheet covering the entire garden. I plan to put the PIR facing downwards in a big funnel like aluminium container.

Hence I think there's no chance of water and direct sunlight falling on the PIR. Additionally, due to double walled (with airgap)polycarbonate sheet, the PIR itself won't get hot because of sun. BTW, I already have a temp. sensor fixed there as part of my home auto which has so far shown temp. from 15 degrees to 23 degrees centigrade.

However, the PIR when installed downwards may have limited visibility but I can always have another one so that both of them cover the entire 12 X 15 area.

Any suggestions?

Rgds,

Viv

[arfur mo]

hi,

detectors are designed to look down when placed virtical on a wall, from a height of about 6 - 8 feet, if you point it down it will have less range. if using a dual tec the microwave will penetrate the plastic so during heavy rain will see water moving, all you need then is a decent draft and hey presto alarm condition.

alarm panels are designed to work 24/7 x 365, also have rechargeable battery back up built in, plc are designed to switch far higher currents whic help clean contacts used by them, but pass micro-amps as used in modern a;arm panels, then you will likely suffer contact degradation over a period of time in your PLC.

you have to write you PLC program from scratch, alarm panels have all that ready and waiting complete with a log of events to aid tracing faults, you just need to select the options needed, like with your external detector you might want double knock or a longer delay before alarm signal, pir in hall on access route backk door on chime and so on.

your time and your money, by all means use a PLC designed to run machinery, but i recommend a proper alarm panel and proper detection as that is proper design concepts, anything else is experimental and likely to be a failure to at least some degree.

regs

alan

[vivtal]

hi,

detectors are designed to look down when placed virtical on a wall, from a height of about 6 - 8 feet, if you point it down it will have less range. if using a dual tec the microwave will penetrate the plastic so during heavy rain will see water moving, all you need then is a decent draft and hey presto alarm condition.

alarm panels are designed to work 24/7 x 365, also have rechargeable battery back up built in, plc are designed to switch far higher currents whic help clean contacts used by them, but pass micro-amps as used in modern a;arm panels, then you will likely suffer contact degradation over a period of time in your PLC.

you have to write you PLC program from scratch, alarm panels have all that ready and waiting complete with a log of events to aid tracing faults, you just need to select the options needed, like with your external detector you might want double knock or a longer delay before alarm signal, pir in hall on access route backk door on chime and so on.

your time and your money, by all means use a PLC designed to run machinery, but i recommend a proper alarm panel and proper detection as that is proper design concepts, anything else is experimental and likely to be a failure to at least some degree.

regs

alan

Hi,

Thanks Alan, I think I will go with your advice. Prior to the DSC panel, I had a 4 zone wired Wickes security panel, which I will again use after sourcing Redwall etc. external PIRs (I guess that would take some time to source )

Let the PLC be used for home-auto and nothing else. Mitsubishi alpha controllers are also specifically designed with home-auto in mind in addition to factory auto.

Rgds,

Viv