To get the exact model of your unit, check this article: Where to get the model number?
Click the link below to download the manual.
DVR - (4480V, 4480RN, 4480G, 4580V, 4580G, 4580RN, 4680, 4680A, 4680RN, 4685, 4685RN, 4780V, 4ch 4980V, 8ch & 16ch 4980, 5580, 5580A, 5580G, 5580G2, 5580RN, 5580RU, 5680, 5680A, 5680RN)
NVR - (8580, 8580RN, 8780, 8780RN)
Wizard Quick Start Guide (QSG) - for all recorders listed above