Selection & Interfaces

5.1 Core Product Overview

The smart campus environmental monitoring system comprises six core product categories, each serving a distinct function in the measurement and data acquisition chain. Selecting the right product for each category requires understanding the measurement principle, environmental conditions, maintenance requirements, and interface compatibility. The following overview presents the complete product lineup with representative examples of each category.

Figure 5.1: Core Product Lineup — Outdoor Noise Monitor, PM Sensor, Indoor Air Quality Monitor, Edge IoT Gateway, Multi-parameter Water Probe, Field Equipment Cabinet

5.2 Interface Logic Diagram

The edge gateway serves as the central integration point for all field devices, providing multiple interface types to accommodate the diverse communication protocols used by environmental sensors. The interface logic diagram illustrates the complete connection topology of the edge gateway, showing all input and output ports, their associated protocols, and the external devices connected to each port. Understanding this interface map is essential for system integration planning and troubleshooting.

RS485 Modbus RTU is the dominant wired protocol for outdoor environmental sensors due to its robustness, long cable runs, and multi-drop capability. The edge gateway typically provides four independent RS485 ports, each capable of addressing up to 32 devices on a separate bus. This isolation prevents a fault on one sensor bus from affecting other zones. The 4–20 mA analog input accommodates legacy sensors that predate digital communication standards.

Figure 5.2: Edge Gateway Interface Logic Diagram — Complete Port Map with Protocols and Connected Devices

5.3 Sensor Selection Criteria

Sensor selection must be driven by the measurement requirements of the application, not by cost alone. The critical selection criteria include measurement principle, measurement range, accuracy, response time, operating environment, maintenance requirements, and interface compatibility. The following table provides a structured comparison of the key selection criteria for each sensor category.

5.4 Core Product Function Table

The comprehensive product function table below provides a complete reference for all core products in the system, covering their functional capabilities, configuration options, and integration requirements. This table is intended as a procurement reference and integration checklist, ensuring that all required functions are specified and verified during the commissioning process.

5.5 Edge Gateway Selection Guide

The edge gateway is the most critical component in the system architecture, as it determines the reliability, scalability, and security of the entire monitoring network. Selection must consider not only the current requirements but also the expected growth in sensor count, the need for additional protocol support, and the security requirements of the deployment environment. The following comparison table covers the key selection dimensions for edge gateway products.