Installation And Connection - GEM PTZ722 Installation And Operation Manual

7. Installation and Connection

Please read the keyboard and speed dome manuals carefully before connecting wires. Any incorrect
connections may cause permanent damage to the equipment. When connecting wires, always switch
off the power supply first. The PTZ722 keyboard must not be exposed to damp or wet conditions
that may short circuit the unit or cause electric shock.. Always check that the keyboard is correctly
connected to a regulated 12v power supply 500mA minimum and that the polarity is correct.
RS485 connection
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 IDENTICALLY so that if you have to swap the A & B
lines over at the keyboard you know all domes are wired the same!!
The PTZ722 adopts the following RS485 convention:
RS485 + or A
Connect the RS485 data cable to the connections on the rear of the keyboard (see diagram above).
Note that the brown connection is the RS485 + A Line connection and the blue is the RS485 – B
Line connection.
It is advisable to use CAT5 cable to connect the RS485 data cable from the dome to the keypad. You
- Connecting the Keypad to the Dome.
The dome is controlled by an RS485 data signal that is produced
by the PTZ722 keypad or a compatible DVR. This data signal
tells the dome to pan, tilt, zoom etc.
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
RS485 – or B
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