Q-See QC40198 - Manual (Page 28)

INSTALLATION & CONNECTION
QC40198 User Manual
19 | P a g e
How to connect PTZ camera
a. Ensure the camera has the same grounding with combo DVR otherwise you may not control the PTZ. Shielded
twisted wire is recommended and the shielded layer is used to connect to the ground.
b. For excessively long signal wires
, 120Ω should be parallel connected between A, B lines on the far end to
reduce reflection and guarantee the signal quality.
c. 485 A, B” of combo DVR cannot parallel connect with “485 port” of other device.
d. The voltage between of A, B lines of the camera should be less than 5v.
e. Ensure the front end device is soundly grounded. Improper grounding may result in chip damage.
3.7.1 Alarm Input and Output Details
You can refer to the following chart and Figure 3-7 for alarm input and output information.
Figure 3-7
Parameter
Grounding Alarm
Ground line
Alarm Input 1, 2, …, 8 becomes valid in low voltage.
1-NO C，
2-NO C， Two NO activation outputs.
CTRL 12V Controls the power output
You need to close the device power to cancel the alarm.
A/B 485 communication port. Used to control devices such as PTZ.
Please parallel connect 120
Ω between A/B cables if there are too
many PTZ cameras
AB Connection
port