Rain and Snow Presence Sensor, Relay & RS485

Dimensions (unit: mm)

Details

Q1: How does the auto-heating function work on the Rain and Snow Presence Sensor?
A1: The sensor automatically activates heating when the ambient temperature drops below 15°C, raising the temperature up to 40°C to prevent ice and condensation buildup. Both the heating start threshold and maximum temperature are software-configurable via Modbus, allowing users to adjust settings based on specific climate conditions.

Q2: What is the difference between the relay output and RS485 output on the Rain and Snow Presence Sensor?
A2: The relay output (normally open) provides a simple on/off contact signal that can directly control external devices such as sprinkler valves or alarm systems, with a load capacity of 250VAC 1A / 30VDC 1A. The RS485 Modbus output transmits digital precipitation presence data for integration with PLCs, data loggers, and host computer systems, supporting function codes 03 and 06 for flexible remote monitoring and configuration.

Q3: How does the AC measurement technology in the Rain and Snow Presence Sensor improve reliability?
A3: Unlike DC measurement methods that cause electrode oxidation and electrolysis over time, the AC impedance measurement technology uses alternating current to prevent chemical reactions on the gold-plated sensing elements. This ensures long-term sensitivity and stable performance without signal drift, even in high-humidity or rainy environments, significantly extending the sensor's service life.

Tips: How do I choose the right output configuration for my Rain and Snow Presence Sensor?

Selecting the appropriate output depends on your control system and application needs. Consider the following options.

• Relay output (normally open) is ideal if you need to directly control external devices such as solenoid valves, alarm buzzers, or indicator lights. It provides a simple on/off contact signal with a load capacity of 250VAC 1A / 30VDC 1A, requiring no additional controller or programming.
• RS485 output is recommended for integration with PLCs, data loggers, or host computer systems. It transmits digital precipitation presence data via the Modbus protocol, supporting function codes 03 and 06 for remote monitoring, data logging, and parameter configuration such as heating temperature or sensitivity.
• Both outputs can be used simultaneously if your system requires both local device control and remote data transmission. This provides maximum flexibility without the need to choose one over the other.
• Consider your wiring distance. RS485 supports longer cable runs up to 1200 meters with better noise immunity, while relay output is suitable for shorter distances and simpler installations.

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