Foreword - Dahua NVR21-4KS3 Series User Manual

General
This user's manual (hereinafter referred to be "the Manual") introduces the installation, functions and
operations of the Network Video Recorder (NVR) devices (hereinafter referred to be "the Device").
Read carefully before using the Device, and keep the manual safe for future reference.
Safety Instructions
The following signal words might appear in the manual.
Signal Words
Revision History
Version
V2.3.5
V2.3.4

Foreword

Meaning
Indicates a high potential hazard which, if not avoided, will result
in death or serious injury.
Indicates a medium or low potential hazard which, if not avoided,
could result in slight or moderate injury.
Indicates a potential risk which, if not avoided, could result in
property damage, data loss, reductions in performance, or
unpredictable results.
Provides methods to help you solve a problem or save you time.
Provides additional information as a supplement to the text.
Revision Content
● Added 26 models.
● Updated people counting.
● Updated EPTZ linkage.
● Updated AcuPick.
● Updated camera encoding.
● Added camera audio and remote
warning light.
● Added PPE detection.
● Added some models.
I
User's Manual
Release Time
November 2023
August 2023