Re: found some good deals ......

[James B <denco2@xxxxxxxxx>]

On Mar 6, 7:26=A0am, JoeRaisin <joeraisin2...@xxxxxxxxx> wrote:
> On 3/5/2011 9:29 PM, Chuck wrote:
>
>
>
>
>
> > I found a few good deals and they are in the mail:
>
> > 1) Speco HT650PT10X High Resolution Motorized Dome Camera
>
> > 2) Speco DVR4TL250 4 Channel DVR
>
> > Now a few questions please -- the DVR has BNC camera inputs but the
> > instructions for the camera are a little more complex:
>
> > ------------
>
> > Connect the camera using the supplied terminal block:
>
> > A) Connect the control unit via the twisted, 2-conductor line (max leng=
th
> > length 1200 meters) to the pin array 5 (RS485A) and 6 (RS485B). =A0Conn=
ect all
> > cameras in parallel to this 2 conductor control line.
>
> > B) Feed the video signal at contact 3 via a shielded cable to the video
> > input of the following unit (eg, monitor, camera switcher, video splitt=
er)
>
> > Connect the shield to contact 4.
>
> > C) 12V + to pin 1 and ground to pin 2.
>
> > -----------
>
> > Ok now ..... RS485 control signals interface at a terminal block on bot=
h the
> > camera and DVR. =A0What is the best twisted wire pair to use for this? =
=A0Would
> > one twisted pair of a Cat 5 cable work ok for 100 yards?
>
> > If Cat 5 cable is used for the RS485 control signals, can I transmit th=
e
> > video and "shield" down a second twisted pair in the same Cat 5 cable?
>
> I suggest you do a little research on what a "shield" is.
>
>
>
> > Could I ship 12 volts and ground down a third twisted pair in the same
> > cable? =A0If so, how far?
>
> > Last problem, the DVR has BNC connectors for video in. =A0Would I just =
soldier
> > a BNC connector on the video cable for connection at the DVR? =A0What a=
bout
> > impedance matching? =A0Any problems to watch for? =A0What am I missing?
>
> > Thanks.- Hide quoted text -
>
> - Show quoted text -- Hide quoted text -
>
> - Show quoted text -

Sorry, I did not think to mention what is meant by shield wire.  The
shield is the overall foil covering that would be around the cat 5
pairs.  It is used to help keep out interferance.  Along with the foil
covering will be a wire with no insulation on it.  This is the wire
that is refered to when shield is mentioned.

James