14Operations flowThe operation flow of the extension unit is as follows.z Rack mountingInstall the extension unit in the rack. (Page 15)Go to step 2 when not installing in the rack.x➡➡ConnectionsConnect the extension unit to the recorder. (Page 17)c➡Startup Turn on the power of the extension unit. (Page 18)Turn on the power of the extension unit before turning on the power of therecorder.v➡Installation of the hard diskdrivesWhen using a network disk recorder, install the HDD units using the buttonsand checking the LCD on the front panel of the recorder. (Page 24)When unformatted hard disk drives are installed, they will automatically beformatted.According to your needs, determine the operational mode. (Page 29)Refer to the manuals provided with the recorder for further information.b➡When changing the assignment of the recording areas on the hard diskdrives, display the disk configuration menu from the setup menu and formatthe hard disk drives.Refer to the manuals provided with the recorder for further information.n Start operationWhen necessaryReplacement of the hard diskdrivesWhen using a network disk recorder, if a hard disk drive fails, perform shut-down process of the faulty disk using the buttons and checking the LCD onthe front panel. Then, replace the faulty disk and recover data. (Page 23 -31)Refer to the manuals provided with the recorder for further information.mFormatting of the hard diskdrives