Digital Video Recorder User Manual 
 
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•  HTTP: Acronym for Hypertext Transfer Protocol. A protocol to transfer hypertext request 
and information between servers and browsers over a network 
•  PPPoE: PPPoE, Point-to-Point Protocol over Ethernet, is a network protocol for encapsulating 
Point-to-Point Protocol (PPP) frames inside Ethernet frames. It is used mainly with ADSL 
services where individual users connect to the ADSL transceiver (modem) over Ethernet and 
in plain Metro Ethernet networks. 
•  DDNS: Dynamic DNS is a method, protocol, or network service that provides the capability 
for a networked device, such as a router or computer system using the Internet Protocol 
Suite, to notify a domain name server to change, in real time (ad-hoc) the active DNS 
configuration of its configured hostnames, addresses or other information stored in DNS. 
•  Hybrid DVR: A hybrid DVR is a combination of a DVR and NVR. 
•  NTP: Acronym for Network Time Protocol. A protocol designed to synchronize the clocks of 
computers over a network. 
•  NTSC: Acronym for National Television System Committee. NTSC is an analog television 
standard used in such countries as the United States and Japan. Each frame of an NTSC 
signal contains 525 scan lines at 60Hz. 
•  NVR: Acronym for Network Video Recorder. An NVR can be a PC-based or embedded system 
used for centralized management and storage for IP cameras, IP Domes and other DVRs. 
•  PAL: Acronym for Phase Alternating Line. PAL is also another video standard used in 
broadcast televisions systems in large parts of the world. PAL signal contains 625 scan lines 
at 50Hz. 
•  PTZ: Acronym for Pan, Tilt, Zoom. PTZ cameras are motor driven systems that allow the 
camera to pan left and right, tilt up and down and zoom in and out. 
•  USB: Acronym for Universal Serial Bus. USB is a plug-and-play serial bus standard to interface 
devices to a host computer. 
18.3  Troubleshooting 
  No image displayed on the monitor after the device is starting up normally. 
Possible Reasons: 
— No VGA or HDMI connections. 
— Connection cable is damaged. 
— Input mode of the monitor is incorrect. 
Step 1 Verify the device is connected with the monitor via HDMI or VGA cable. 
If not, please connect the device with the monitor and reboot. 
Step 2 Verify the connection cable is good.