Datavideo PTC-120, Instruction Manual, Page: 10 / 51

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3.2 Multiple Cameras Cascade
The PTC-120 camera can also be used in an environment where multiple cameras are required.
With RS-232 INPUT/OUTPUT ports, the user is allowed to cascade up to seven cameras, which are
subsequently controlled by either a computer (Please download a utility program first from
http://www.serialporttool.com/PTZ.htm in case you need to control the camera via a PC) or a
SONY VISCA compatible controller. RS-232C and RS-422 system setups for connection of multiple
cameras are illustrated in the respective diagrams below.
RS-232C Cascade Connection RS-422 Cascade Connection
For wiring information, please see Section 11 for RS-232C and Section 12 for RS-
422.
However, the connection will be broken if one unit is powered off. In other words, the cameras
connected subsequent to the broken one will become uncontrollable by RMC-190. For example,
in the above diagram, if cameras #2 and #3 are defective or powered off, all camera connections
(4/5/6/7) after camera #3 will be cut off from the daisy chain and RMC-190 will not be able to
control them even if the cameras are still operable.
The cameras have to be at least in the standby mode for the entire daisy chain connection to stay
controllable by RMC-190. In the above example, if cameras #2 and #3 are in standby mode, the
user will still be able to control all cameras after camera #3 from RMC-190.
If the camera is powered off or defective, there will be no LED lighting in standby mode. The user
should check the LED lighting first if the daisy chain is found to be broken.