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Amphenol Advanced Sensors LET-Basic Alarm Module

Amphenol Advanced Sensors LET-Basic Alarm Module uses the standard MODBUS-RTU protocol and an asynchronous serial 2-wire RS485 port. The host computer data reading interval shall be ≥ 500ms (recommended 1s). Its default device address is 01 and can be configured via host computer commands or LEAK-Talk software. The Amphenol Advanced Sensors LET-Basic Alarm Module supports BACnet IP and Modbus RTU/TCP.

Features

  • The LET-Basic alarm module is small in size, and all installation and operation can be easily completed without opening the module
  • The alarm module is an alarm mode of automatic reset after leak elimination
  • The output of the alarm indicator, buzzer, and relay follows the automatic reset
  • Stepless adjustment of detection sensitivity, one key mute button for alarm, and buzzer setting switch
  • The LET-Basic Alarm module is suitable for air conditioning equipment, computer room, liquid container, pump tank, and other occasions where leakage monitoring and alarm are needed
  • Total cable length 500 meters
  • Small size, guide rail installation
  • One-click silence, automatic reset function
  • RS485 MODBUS communication

Applications

  • Air conditioning equipment
  • Computer room
  • Liquid container
  • Pump tank
  • Mission-critical applications where leak detection is essential

Kit Contents

  • Controller
  • Power extension wire
  • Lead cable - 3 meters (~10ft)
  • Testing cable - 15 meters (~50ft)
  • Wire end connector

Specifications

  • Communication parameters
    • Data transfer rate: Baud rate 9600 BPS
    • Data transmission format: N (parity check), 8 (data bit), 1 (stop bit)
    • Device default address: 01
    • RS485 wiring port: Standard two-wire asynchronous communication, 8RS+, 9RS-
  • Leak controller
    • Dimensions/weight: L 86mm x W 58mm x H 52mm; 100g
    • Plastic casing: Black fireproof ABS material, DIN 35mm track installation
    • Detection sensitivity: Full-range stepless adjustment, response time less than 1 second (at maximum sensitivity)
    • Power requirement: 12VDC to 24VDC/AC, standby current 70mA, alarm current 120mA
    • Relay output: 1SPDT normally open and normally closed output, with a maximum output power of 220VAC/2A
    • RS485 output: RS + RS- dual communication interfaces, device address 1 to 255
  • Non-positioning detection cable
    • Weight: 30g/m
    • Cable diameter: 5.5mm
    • Cable length: 15m supplied with kit (custom lengths are available up to 500m)
    • Maximum exposure temperature: 85°C
  • Module
    • Patch cable: Optional
    • Lead cable length: 3m
    • Cable connector: Standard component
    • Hold downs: Standard component
Infographic - Amphenol Advanced Sensors LET-Basic Alarm Module

Typical Application System Diagram

Application Circuit Diagram - Amphenol Advanced Sensors LET-Basic Alarm Module
Published: 2026-08-07 | Updated: 2026-08-07