1. Modular design supporting hot plug, Easy operation and user friendly; 2. AC and DC power supply, build-in rechargeable battery to support 3-6 hours; 3. 720 hours trend data replaying, 2 hours waveform storing and replaying; 4. Sound, light, text prompt, 3 levels alarm and volume can be adjusted; 5. Link with central monitoring system via wire or wireless (web card ).