14
Powering the PTZs-
All the PTZs will need power. For this PTZ it is a 24V A.C power supply. The power supply
must be capable of delivering at least 1.1A per PTZ.
You can either power each PTZ with its own PSU locally to it or have the PSU’s remotely
situated perhaps near the keyboard or DVR. The PTZs require a current of about 410mA
when LEDs are off and 850mA when LEDs are on. So you must take this into consideration
when working out maximum cable runs.
A popular way to power the PTZs is using our COMPOSITE VIDEO cable (or
shotgun as its also known) as this cable can carry the power to the PTZ and the
video signal back to the monitor or DVR.
The power connection
The RED & BLACK cable coming out of the PTZ are for power. Connect a suitable 24V A.C
power supply to this pair of cores.
The BNC connector is the “VIDEO-OUT” from the camera and goes to the monitor or
“VIDEO-IN” of a DVR camera input.
The White and Green cores are the data cables. These are the cores that carry the RS485
control signal to the PTZ from either the keyboard or the DVR. The White cable is the
RS485+ and the Green is the RS485 - cable. The next section of the instructions gives more
detail on how to connect the RS485 data. Please also read the RS485 WIRING METHODS &
TIPS section towards the beginning of these instructions.
If the voltage of the PTZ drops below around 20V A.C it will fail to initialise. Obviously you
can power the PTZs locally if you wish.
RS485 connection
-
Connecting the Keypad or DVR to the Dome
.
The dome is controlled by an RS485 data signal that is given by either
a KEYPAD or a suitable DVR. This data signal tells the dome to pan,
tilt, zoom etc. Its important that you read the early section of these
instructions to understand the fundamental principle of RS485 cabling
techniques so that you get it right.
RS485 has two cores, A and B or sometimes known as RS485 + (A) and RS485 – (B) if you
get these two the wrong away around then you will not be able to control the dome.
Sometimes installers get the connections right on one dome but not on the other and find only
one dome works. They then swap the wires around at the keyboard only to find out one dome
has now
burst in to life and the other one now failed!! But they don’t put 2 + 2
together and realise their mistake that they have wired one dome different to the other.
Take great care getting these the right way around and make sure you wire each dome
IDENTICALY so that if you have to swap the A & B lines over at the keyboard you
know all domes are wired the same!!