Downlink Command

This chapter describes the downlink commands for device configuration and control. The downlink application port is 85 by default.

General Setting

Item Channel Type Byte Description
Reboot ff 10 1 ff
Collect Interval ff 02 2 UINT16, Unit: s
Re-collect Setting ff 1c 2 Byte 1: re-collect times

Byte 2-3: re-collect interval
Report Interval ff 03 2 UINT16, Unit: s
Data Storage ff 68 1 00: Disable, 01: Enable
Data Retransmission ff 69 1 00: Disable, 01: Enable
Data Retransmission Interval ff 6a 3 Byte 1: 00

Byte 2-3: UINT16, Unit: s, Range: 30~1200, Default: 600
UTC Time Zone ff 17 2 INT16/10
Device Time ff 11 4 Unix timestamp, Unit: s
Sync with with LNS ff 4a 1 ff
Example:
  1. Reboot the device.
    ff10ff
  2. Set collect interval as 20 minutes.
    ff02b004
    Channel Type Value
    ff 02 b004=>04b0=1200s=20 minutes
  3. Set report interval as 20 minutes.
    ff03b004
    Channel Type Value
    ff 03 b004=>04b0=1200s=20 minutes
  4. Set time zone as UTC-2.
    ff17ecff
    Channel Type Value
    ff 17 ecff=>ff ec=-20/10=-2

Data Collection Settings

Item Channel Type Byte Description
Sensor Status ff 18 2 Byte 1: 00=All, 01=Temperature, 02=Humidity, 05=CO2, 06=Barometric Pressure

Byte 2: 00=Disable, 01=Enable
Example:
  1. Disable temperature sensor.
    ff180101
    Channel Type Value
    ff 18 01=Temperature, 00=Disable

Calibration Settings

Item Channel Type Byte Description
Temperature Calibration ff f1 4 Byte 1: 00

Byte 2: 00-disable, 01-enable

Byte 3-4: Calibration value, INT16/10, Unit: °C
CO2 Numerical Calibration ff f1 4 Byte 1: 04

Byte 2: 00-disable, 01-enable

Byte 3-4: Calibration value, INT16, Unit: ppm
CO2 Calibration ff 1a 1 00=Restore Factory Calibration

03=Manual Calibration
Auto Background Calibration ff 39 5

Byte 1: 00-disable, 01-enable

Bytes 2-3: Calibration period, unit: hour

Bytes 4-5: Calibration value, unit: ppm
Pressure/Altitude Compensation ff 87 3

Byte 1: 00-disable, 01-barometirc pressure compensation, 03-altitude compensation

Bytes 2-3: Altitude value, unit: m, range: 0-5000
Example:
  1. Enable temperature calibration and set calibration value.
    fff10001fdff
    Channel Type Value
    ff f1 00=Temperature, 01=Enable

    fdff=>fffd=-3/10=-0.3 °C
  2. CO2 manual calibration after putting device to outdoors for more than 10 minutes.
    ff1a03
    Channel Type Value
    ff 1a 03=Manual Calibration
  3. Enable Auto Background Calibration, set calibration period as 168 hours (7 days) and the value as 400 ppm.
    ff3901a8009001
    Channel Type Value
    ff 39 01=Enable

    a8 00 => 00 a8=168h

    90 01 => 01 90= 400 ppm

Threshold Setting

Item Channel Type Byte Description
Temperature Threshold Alarm ff 06 9 Byte 1: 10=Disable, 51=Below (min. threshold), 52=Over (max. threshold), 53=Within, 54=Below or over

Byte 2-3: Minimum threshold, INT16/10, Unit: °C

Byte 4-5: Maximum threshold, INT16/10, Unit: °C

Byte 6-9: 00000000
CO2 Threshold Alarm ff 06 9 Byte 1: 08=Disable, 49=Below (min. threshold), 4a=Over (max. threshold), 4b=Within, 4c=Below or over

Byte 2-3: Minimum threshold, UINT16, Unit: ppm

Byte 4-5: Maximum threshold, UINT16, Unit: ppm

Byte 6-9: 00000000
Temperature Mutation Alarm ff 06 9 Byte 1: 1d=Disable, 5d=Enable

Byte 2-3: 0000

Byte 4-5: Mutation threshold, INT16/10, Unit: °C

Byte 6-9: 00000000
Alarm Reporting Times ff f2 2 UINT16
Alarm Dismiss Report ff f5 1 00-disable, 01-enable
Example:
  1. Set a temperature threshold as below 15°C or over 30°C.
    ff065496002c0100000000
    Channel Type Value
    ff 06 54=Below or over

    Min. threshold: 96 00=>00 96=150/10=15°C

    Max. threshold: 2c 01 => 01 2c =300/10=30°C