42In this way, you can reduce packets and enhance network transmission efficiency.The following MTU value is for reference only. 1500: Ethernet information packet max value and it is also the default value. It is thetypical setup when there is no VPN. It is the default setup of some router, switch or thenetwork adapter. 1468: Recommend value for DHCP.Click Apply or Save to complete setup.Figure 2-362.9 Pan/Tilt/ZoomNote Slight difference may be found in the user’s interface, due to various protocols. Please make sure the speed domes A/B cables are properly connected to the A/B ports ofDVR. You have properly set PTZ information. Please switch camera monitor channel to current window.2.9.1 Pan/Tilt/Zoom SetupIn the main menu, from SETTING -> SYSTEM -> PAN/TILT/ZOOM, you can see the followinginterface. The Pan/Tilt/Zoom setup includes the following items. Please select channel first. SeeFigure 2-37. Control Mode: You can select control mode from the dropdown list. There are two options:Serial/HDCVI. For HDCVI series product, please select HDCVI. The control signal is sent tothe PTZ via the coaxial cable. For the serial mode, the control signal is sent to the PTZ via theRS485 port. Protocol: If the control mode is HDCVI, please select HDCVI protocol. The default setup is