Downlink Command

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

General Settings

Item Channel Type Byte Description
Reboot ff 10 1 ff
Report Interval ff 03 2 UINT16, Unit: s
LED Indicator ff 2f 1 00: Disable, 01: Enable
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
Example:
  1. Reboot the device.
    ff10ff
  2. Set report interval as 20 minutes.
    ff03b004
    Channel Type Value
    ff 03 b004=>04b0=1200s=20 minutes

Time Settings

Item Channel Type Byte Parameter
UTC Time Zone ff 17 2 INT16/10
Device Time ff 11 4 Timestamp, UINT32, Unit: s
Examples:
  1. Set time zone as UTC-2.
    ff17ecff
    Channel Type Value
    ff 17 ecff=>ff ec=-20/10=-2

CO2 Calibration Settings

Item Channel Type Byte Description
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
Altitude Compensation ff 87 3

Byte 1: 00-disable, 01-enable

Bytes 2-3: Altitude value, unit: m, range: 0-5000
Example:
  1. Manual calibration after putting device to outdoors for more than 10 minutes.
    ff1a03
    Channel Type Value
    ff 1a 03=Manual Calibration
  2. 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

Screen Display Settings

Item Channel Type Byte Description
Screen Display ff 2d 1 00: disable, 01: enable
Last Update Display ff 85 1 00: disable, 01: enable
Screen Smart Mode ff 56 1 00: disable, 01: enable
Least Refresh Time ff 86 2 UINT16, Unit: min, Range: 2-1080
Screen Fresh Time ff 5a 2 UINT16, Unit: s
Screen Content ff f0 4

Byte 1-2: ffff

Byte 3-4: 0=disabled, 1=enabled for every bit
Bit Content
0 Temperature
1 Humidity
2 CO2
3 Emoticon
15-4 All 0
Hibernate Mode ff 75 6 Byte 1: 00=Disable, 01=Enable

Byte 2-3: Start Time, UINT16, Unit: minute, Range: 0-1439

Byte 4-5: End Time, UINT16, Unit: minute, Range: 0-1439

Byte 6: Repeat weekday, per bit 0=Disable, 1=Enable
Bit 7 6 ... 1 0
Sun. Sat. ... Mon. All
Note: If start time equals end time, it means all day.
Example:
  1. Disable the e-ink screen display.
    ff2d00
    Channel Type Value
    ff 2d 00: Disable the display
  2. Disable to display the emoticon.
    ffff0ffff0700
    Channel Type Value
    ff f0 07 00=> 00 07 = 0111

    Emoticon disable, others enable
  3. Enable screen hibernate mode, set the hibernate time between 22:00 to next day 9:00 on week days (Monday to Friday).
    ff7501 2805 1c02 3e
    Channel Type Value
    ff 75

    Byte 1: 01 = screen hibernate enable

    Byte 2-3: 28 05=>05 28=1320 mins =22:00

    Byte 4-5: 1c 02 => 02 1c = 540 mins =9:00

    Byte 6: 3e=00111110 => Monday to Friday enable

CO2 Threshold Settings

Channel Type Byte Description
ff 54 5

Byte 1: 00: disable, 01: enable

Byte 2-3: Bad threshold value, Unit: ppm

Byte 4-5: Polluted threshold value, Unit: ppm
Note: Polluted threshold value must be lower than bad threshold value.
Example:
Set CO2 bad threshold as 1500ppm and polluted threshold as 1000 ppm.

ff5401dc05e803
Channel Type Value
ff 54

01 = enable

Bad threshold: dc 05 => 05 dc = 1500 ppm

Polluted threshold: e8 03 => 03 e8 = 1000 ppm