Auto Dialer On A Dvr System

[sjonley]

Hi all

I need a bit of help from all you superb alarm engineers whom have moved into CCTV.

I am looking at using a GJD GSM autodialer (HYL005) with one of my DVR's. I want the DVR alarm output (NO dry contacts going closed on alarm condition) to be interfaced with the autodialer.

I have downloaded the autodialer manual from GJD's website and looking through the connections, the manual states that both triggers are "bell/siren switched negative, this unit will not operate off a switched ground"

Would someone be so kind to explain what switched negative is. I've heard it mentioned on numerous occasions but having only worked on NO, NC dry contacts on a CCTV system, i haven't got a clue what switched negative means let alone how to interface to it.

Please help.

[james.wilson]

it means switching from 3v+ (ie 12v) to 0v.

most outputs are switched neg, with a resitive pull up.

[breff]

The dialler will need to be powered by a 12vdc psu yes?

If so send the 0v that powers it through the dvr relay (NO) and return to the diallers trigger.

[sjonley]

Ok.

forgive my ignorance.

I power the autodialer from a 12v source.

got that bit then you lost me with the relay. Any chance of a quick diagram on connection of dialer, relay and dvr, emailed or faxed to: 0871 528 9083.

would be much appreciated.

[james.wilson]

tell you what, why dont you give us the manual (ie the output bit) of your dvr and then we can say how to wire it.

James

[breff]

try this

[arfur mo]

try this

hi breff, is it a relay though?

i don't know if it is a transistor stage output, if so that diagram might just 'blow' it.

the o/p is coming from alarms to cctv, so go to wholesaler and get a 'handy' transistorised relay pcb, use the DVR wired to the trigger and the pcb relay, and the springs to input of the dialer is safest option.

if you are more advanced than you need to 'common' the ground (0ve) of the dialer to the DVR so the + output can affect the dialers input.

after all of that above i'm bothered, it depends on the area you viewing but your likely to get dozens if not hundreds of alerts per day, the DVR detection is not on a par with movement detectors for anti-false alarms. so i hope the numbers dialed are on your 'buddy' list or the bill will be fantastic.

imo you will soon disable it

regs

alan

[breff]

Alan, read this part in the OP's first post

I want the DVR alarm output (NO dry contacts going closed on alarm condition) to be interfaced with the autodialer.

Notice anything about the above smilies.....................................................

.....thats right mate they all have glasses on, just jesting.

[arfur mo]

Alan, read this part in the OP's first post

Notice anything about the above smilies.....................................................

.....thats right mate they all have glasses on, just jesting.

i stand corrected (my turn with the whipp next time)

just a bit worried i don't know that kit and people misread the manuals (so to be ultra safe - i don't read them at all )

regs

aln

[sjonley]

Alan / Breff

No you got me confused

Direct wire or via a relay?

... and I don't understand your last posts!