25
4. Set D2D settings of temperature threshold trigger.
5.4 Historical Data Enquiry
EM300 series sensor supports sending downlink commands to enquire historical data for
specified time point or time range. Before that, ensure
the device time is correct and data
storage feature was enabled to store the data
.
Command format:
Reply format:
Data format:
ff
06 (Set Threshold
Alarm)
CTRL:cc =>11001100
100 = below or above
Min:96 00=> 00 96 = 15°C
Max: 2c 01=>01 2c = 30°C
ff 79 01011001
Channel
Type
Value
ff
79 (Set D2D
settings )
Number: 01, temperature threshold trigger
Function: 01, only use D2D
D2D Command: 1001=>0110
Channel
Type
Description
fd
6b (Enquire data in time point)
4 Bytes, unix timestamp
fd
6c (Enquire data in time range)
Start time (4 bytes) + End time (4 bytes),
Unix timestamp
fd
6d (Stop query data report)
ff
ff
6a (Report Interval)
2 Byte, unit:s,
Range: 30~1200s (60s by default)
Channel
Type
Description
fc
6b/6c
00: data enquiry success
01: time point or time range invalid
02: no data in this time or time range
20
ce (Historical Data) Data time stamp (4 Bytes) + Data Contents (Mutable)
Sensor
Description
EM300-TH
Tempe Humidity