User’s Manual13Pin Definition for 8ch/16ch Model:Pin Definition Pin Definition1 ALARM OUT O 14 Alarm OUT C2 ALARM OUT COM 15 GND3 RS485 D/R+ 16 GND4 RS485 D/R- 17 Reserved5 Reserved 18 ALARM In 9 (for 16ch only)6 ALARM In 1 19 ALARM In 10 (for 16ch only)7 ALARM In 2 20 ALARM In 11 (for 16ch only)8 ALARM In 3 21 ALARM In 12 (for 16ch only)9 ALARM In 4 22 ALARM In 13 (for 16ch only)10 ALARM In 5 23 ALARM In 14 (for 16ch only)11 ALARM In 6 24 ALARM In 15 (for 16ch only)12 ALARM In 7 25 ALARM In 16 (for 16ch only)13 ALARM In 8Power JackThe X4/X8/X16 DVR has a free voltage DC power connection jack. Pleaseconnect the power adapter that ships with the unit.NOTE: Use of other power adapter may cause overloading.