IC Realtime DVR-FLEX8E Product Manual - Page 29

485 A/B 485 communication port. They are used to control devices such as PTZ. Please parallel connect 120TΩ between A/B cables if there are too many PTZ decoders. 3.8.2 Alarm Input Port Please refer to the following sheet for more information. z Normal open or Normal close type. z Please parallel connect COM end and GND end of the alarm detector (Provide external power to the alarm detector). z Please parallel connect the Ground of the DVR and the ground of the alarm detector. z Please connect the NC port of the alarm sensor to the DVR alarm input(ALARM) z Use the same ground with that of DVR if you use external power to the alarm device. Figure 3-2 3.8.3 Alarm Output Port z Provide power to peripheral alarm device. z To avoid overloading, please read the following relay parameters sheet carefully. z RS485 A/B cable is for the A/B cable of the PTZ decoder. Model: Material of the touch Rating （Resistance Load） Insulation Surge voltage Length of open time Length of close time JRC-27F Silver Relay Specification Rated switch capacity Maximum switch power Maximum switch voltage Maximum switch currency Between touches with same polarity Between touches with different polarity Between touch and winding Between touches with same polarity 3ms max 30VDC 2A, 125VAC 1A 125VA 160W 250VAC, 220VDC 1A 1000VAC 1minute 1000VAC 1minute 1000VAC 1minute 1500V (10×160us) 3ms max 19