42485 A/B 485 communication port. They are used to control devices such asdecoder. 120Ω should be parallel connected between A, B lines ifthere are too many PTZ decoders.T+,T-,R+,R- They are four-wire full-duplex RS485 portT+ T-: output wireR+ R-: input wire3.7.2 Alarm Input PortPlease refer to the following sheet for more information. Grounding alarm inputs. Normal open or Normal close type) Please parallel connect COM end and GND end of the alarm detector (Provideexternal power to the alarm detector). Please parallel connect the Ground of the DVR and the ground of the alarm detector. Please connect the NC port of the alarm sensor to the DVR alarm input(ALARM) Use the same ground with that of DVR if you use external power to the alarm device.Figure 3-23.7.3 Alarm Output Port Provide external power to external alarm device. To avoid overloading, please read the following relay parameters sheet carefully. RS485 A/B cable is for the A/B cable of the PTZ decoder. T+,T-,R+,R- are four-wire double duplex RS485 port.T+ T-: output wireR+ R-: input wire3.7.4 Alarm Output Relay ParametersNoteRefer to the actual product for relay model information.Relay SpecificationModel HFD23/005-1ZS HRB1-S-DC5VMaterial of the touch AgNi+ gold-plating AuAg10/AgNi10/CuNi30Rating(ResistanceLoad）Rated switchcapacity 30V DC 1A/125V AC 0.5A 24V DC 1A/125V AC 2AMaximum 62.5VA/30W 250VA/48W
