71: PTZ Control Button⑥Network PTZ Function can be controlled when the PTZ camera is properly connected to RS-485.. PT : Control Pan/Tilt. Press PT button and control Pan/Tilt by using following buttons.- : Press this button to move right- : Press this button to move left- : Press this button to move up- : Press this button to move down. ZF : Control Zoom/Focus. Press ZF button and control Zoom/Focus by using followingbuttons.- : Press this button to Zoom in- : Press this button to Zoom out- : Press this button to Focus in- : Press this button to Focus out: HDD Free Space⑦HDD free space information from DVR.: Audio ON/OFF button⑧: Audio Volume control.⑨SVR-440 support Two-way Audio communication. Both of DVR site and clientshould have mike and speaker installed to use the function.: Alarm⑩When Alarm occurs on DVR, the color will turn to red.