Speco Technologies SIPSD37X - Manual (Page 13)

37X Speed Dome Camera 13/50
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Terminal Resistor Setup
1 2 3 4
ON
ON
The terminal resistor is used for the following cases.
z
Case 1 : In case that the control cable length between a camera
and a controller is relatively very long (1:1 Connection)
If the communication cable length is very long, the electrical signal
will bound in the terminal point. This reflected signal causes
distortion of original signal. Accordingly, the camera can be out of
control. In this case, the terminal resistor of both sides i.e. the
camera and the controller must be set to ‘ON’ state.
z Case 2 : In case that multiple cameras are connected to a
controller.
Due to similar reasons with the case 1, the terminal resister of the
controller and the last camera must be set to ‘ON’ state. The last
camera means the camera farthest in cable length from the
controller. Do not turn on the terminal resistor of all the cameras on
the same communication cable.
Controller
#1 #2 #n
Terminal Resistor ON
RS-485
Terminal Resistor
OFF
Terminal Resistor
OFF
Terminal Resistor
ON
INSTALLATION 2