Re: DSC 632 hybrid system: Multiple contacts on one transmitter

["Frank Olson" <feolson@xxxxxxxxxx>]

"glevin" <mikengroups@xxxxxxxxx> wrote in message
news:1115859570.205927.187300@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>I recently purchased a DSC 632 hybrid system and found that the
> instructions for the WLS925L-433 door/window transmitters say not to
> put more than one contact on the external loop and "the wires
> connecting the external device to the input terminals must not exceed
> 18 inches, provided that the resistance of the wire dies not exceed 100
> Ohms."
>
> I am replacing an old wireless system on which I had multiple
> door/window contacts and about 40 feet of wire on one transmitter. I
> measured the resistance of that normally-closed loop and got 18 Ohms. I
> tested the transmitter often and it functioned flawlessly.
>
> Why should there be a problem with multiple sensors on the external
> loop of the DSC transmitter as long as the resistance is under the
> specified 100-Ohm limit? Is DSC just trying to sell more transmitters,
> or is there a better reason for the stated limitations? Parts of my
> house are impractical to hard wire and I don't want to buy a separate
> transmitter for each door and window if one transmitter can handle
> multiple contacts.
>
> I would appreciate any advice relating from folks with experience or
> knowledge with this issue. Thanks in advance for your assistance.


The concern stems more from the fact that the extra wire in the loop tends
to act like an antenna which could result in false alarms.  For the sake of
your customer's convenience and so as not to risk the wrath of the "RFI
Gawd", I'd suggest you consider follow their directions (even if it means
adding a few more transmitters).  This having been said, I've got a couple
of units out there with more than one contact on them and wire runs of
around 15' (on average) with *zero* problems...  Mind you, the could be
"muzzled"...  ;-)
>