IFS Documentation Center

# Dry Contact Sensor

Image from dependency

# Product Description

The Dry Contact Sensors Sensor provides accurate contact status of dry contact signal. Dry Contact Sensors can convert dry contact signal into digital signal with LoRaWAN protocol.

# Product Features

  • Dry Contact Detection and Sampling Circuit
  • Instant Handling on Dry Contact State Change
  • Customizable Hold State Confirmation Period (Default 5s)
  • Configurable Heartbeat Cycle
  • Force Sampling by Magnet and On-board Force Test Button
  • Design and Assembly in Hong Kong, local engineering support

# Hardware interface

# Sensor Case

Image from dependency

# PCB Main Features

Image from dependency

# Software Interface

# LoRaWAN Specification

  • Specification 1.0.3, Region AS923
  • Class A or C (Default Class A)
  • ABP or OTAA (Default OTAA)

# Payload Inclusion

  • Battery Voltage (Unit: V, 3d.p.)
  • Dry Contact Logic Level (Active High)
  • Uplink Type (0: Heartbeat and Force Samplinng, 1: State Change)
Description Downlink Format (HEX) Value Range (HEX) Default Value Dec (HEX)
Restart 1AFF / /
ADR On/Off AD0XAD 0 or 1 0
Change Data Rate ADA0XFF 2 to 5 2
Change Heartbeat Cycle (unit: second) CDXXXXFF 0 to FFFF 1Hour: 3600 (0E10)
Change Heartbeat Cycle (unit: second)
Extended Range to support 1/2 years		 CDXXXXXXFF 0 to FFFFFF 1 Day: 86400 (015180)
Change Dry Contact Hold-State Confirmation Period to XX Second(s) DCXXDC 0 to 255 5 (05)

# Routine Behaviour

  • On dry contact channel state change, sensor hold n seconds (default 5) on tracking stable channel state. When the change is valid after the confirmation period, lorawan uplink will be sent.
  • When Magnet Sensor is triggered at the side of case or On-board TEST button is pressed (and released within 5 seconds), green LED turns on and interrupt triggers. The sensor will force send an uplink for current channel state.
  • If no valid state change appears within a cumulative heartbeat cycle (default 1 hour), the sensor will also force send an uplink.
  • When Magnet Sensor is triggered at the side of case and holded over 5 seconds, the sensor will resend join request (if current Network Join Mode is OTAA).

# LoRaWAN Payload Codec

# Chirpstack v4 codec

function decode_toHexString(bytes) {
    return bytes.map(function(byte) {
        return ("00" + (byte & 0xFF).toString(16)).slice(-2)
      }).join('')
}

function decodeUplink(input) {
  var tohex = decode_toHexString(input.bytes);
  var fPort = input.fPort;
  var return_json = {};
  if(fPort == 0) {return {data:return_json};}
  
  return_json["VCC"] = parseInt(tohex.slice(0,4), 16)/1000;
  if(fPort ==3) 
    return_json["Uplink_Type"] = 1;
  else  
    return_json["Uplink_Type"] = 0;
  return_json["Dry_Contact_Logic"] = parseInt(tohex.slice(5,6),16);
  return {data:return_json};
}

function encodeDownlink(input) {
  return {
    bytes: [225, 230, 255, 0]
  };
}

# Specification

Reporting Data Type
Battery Voltage Unit: V
Dry Contact Logic Level 0 or 1, Active High
Uplink Type 0: Heartbeat or Force Sampling, 1: State Change
Force Sampling Trigger 1. Magnet Trigger at Case Side
2. Test Button On-Board
LoRaWAN Specification 1.0.3
LoRaWAN Class A, C (Default A)
LoRaWAN Network Join Mode OTAA, ABP (Default OTAA)
LoRaWAN Configuration LoRaWAN Downlink
Rated Voltage 3.3 ~ 4.2V (Typ. 3.6V)
Battery Type 1* 8Ah 3.6V LifePo Battery
Battery Lifespan 2 years
Working Mode Typical: 70mA Max 120mA @Tx
Sleep Mode 10uA
Routine Interval (Default) 1. 1-hour Heartbeat
2. 5-Second Hold State Confirmation Period
Operating Temperature -20 ~ + 125°C
Relative Humidity <= 85%RH
Dimension 110 *80 *50 mm
(Reference only. Please refer to the delivery.)
Protection Level Rating IP67

# Revision

Version Date Content
1.0 28 May 2024 Initial Release
1.1 29 May 2024 Add Customeized Version for Housing Authority

# Datasheet

Click to download

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